Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang Eds© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6 Table of contents Material science and advanc
Trang 2MACHINERY, MATERIALS SCIENCE AND ENGINEERING APPLICATIONS
Trang 4PROCEEDINGS OF THE 6 INTERNATIONAL CONFERENCE ON MACHINERY,
MATERIALS SCIENCE AND ENGINEERING APPLICATIONS (MMSE 2016), WUHAN,
HUBEI, CHINA, 28–29 OCTOBER 2016
Machinery, Materials Science
and Engineering Applications
Trang 5CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business
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www.crcpress.com – www.taylorandfrancis.comISBN: 978-1-138-02957-6 (Hbk)
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Trang 6Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang (Eds)
© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6
Table of contents
Material science and advanced materials
A PEG-400-etherified 2D resin improves the water absorption property
H Ding, Y He, Y.K Jiang, Y.Q Wu & X.X Yang
Selective formation of AlPO4-21 and AlPO4-12 molecular sieves by microwave
P.M Chang
Parameter optimization of forming limited diagram based on virtual
Q Yu, J Liang & L.-W Tian
Effects of CaTiO3 addition on the microstructure and microwave dielectric
W Hu, C.X Yin, H.T Sui, W.X Shi, H.J Sun & S.F Huang
Research on the biomimetic materials with highly oriented animal bone
Y.W Yuan, J Yu & L.M Yan
The damage variable and tensile properties of T2 pure copper with
L Li & Z.M Shi
Electrical engineering and automation control
The network control technology of the shipbuilding gantry crane based on PLCs 47
F Zhu, M Zhou, J.H Huang & J.H Huang
Development of a certain detecting device for a NCB proofing system
D.B Zhang, C.A Qiao, Y Liu, W.Q Huang & X.Y Li
A classification recognition method based on an improved kernel function
W.W Xiong, W Liang & M.X Su
Application of fuzzy comprehensive evaluation in fault diagnosis of
C Wu, D Wu, X.Y Mao, H.Y Ding, J.H Hu & Y.O Liu
Trang 7A study on the time–space characteristics of soil resistivity of substations in China 73
X Xu, X Liu, S Wang, Z.Z Li, G Liu & Z Wang
Identification of rotary kiln cylinder bending by using wavelet and fourier transforms 81
L Qin, Y Zhang & Q Peng
D.B Zhang, Y Liu, C.A Qiao & W.Q Huang
X.D Yu & H.Z Zang
B Feng, C.D Qiu, C.Q Xu & X.B Wu
Restoring force characteristic for motor bearing fault based on dynamic analysis 109
R Guo, C.D Qiu, X.B Wu & C.Q Xu
A design of the totem pole output circuit for current mode PWM controllers 115
D Zhao
L.L Wan
Y.F Liu, T.M Zhang, J.J Yang & Q Tian
Z Zhang, J.M Yang, Y.F Zhang & R.B Zhou
L.-L Wan & W.-P Zhou
D.B Zhang, C.A Qiao, Y Liu & W.Q Huang
Modeling and analysis of active heave compensation control in marine cranes 147
F Zhu & J.H Huang
Identifying the metal magnetic memory signal feature for stress concentration zone 153
J Zhang & S.Z Zhu
Command-filtered backstepping stabilization of nonlinear systems with quantized input 161
X Yu & P Zhuang
Application of genetic algorithm-support vector regression for estimating
Z.W Xia, X.T Wang, K.J Mao, G.S Shao, H.Y Ren & Y.Y Fang
Full-waveform current differential protection based on optical current transformers 175
K Yue, G.-Q Zhang, C Yang, Z.-Q Liu & D Yin
Numerical calculation of the infinite element method in an inhomogeneous medium 181
Y.Q Dun, Y Kong & Y.L Wang
Z.Y Wei, C.H Zhu & Z Yang
A scheme on the force and motion control of manipulator robots based
W Fang, Z Yang & Z.Y Wei
X.W Han & D.H Xu
Trang 8Electronic engineering
Q Li, Z Wang, J.L Wang & J.Y Li
H.S Zhang, G.Y Wang, M.Y Lu & R.Y Zhu
Applied mechanics
Z.G Chen, Y.J Yan, W Han & H.F Li
A modeling method of the bolted joint structure and analysis of its stiffness characteristics 229
G.Q Jiang, J.W Li & G.J Tang
An experimental study on the propulsive performance of a bionic dolphin tail fin 237
C Ma, L Sun, C.-X Bian, C.-K Ding & X.-Y Shen
A study on the lubrication performance of end faces with diamond macro-pores 241
X.P Cheng, L.P Kang, Y.L Zhang, B.L Yu, X.K Meng & X.D Peng
A study on the performance of self-adaptive mechanical seals under
X.P Cheng, Y.L Zhang, L.P Kang & B.L Yu
B.L Chen & Z.Q Xie
Mechanical engineering
H.B Yin, M.C He, S.S Huang & J.F Li
A study on vibration responses of mechanical systems with an impact on clearance joints 273
Z.F Bai, X Shi, J.J Zhao & J Chen
Y.Q Wang & G.P Zhang
Large deformation structure analysis of complex telescopic boom system
L Xu, X.D Xu, Z.J Tian & C.J Jin
Master–slave control of variable parameters of a vehicle hydraulic system support 297
H Lu, L.C Shi, Q.Y Wei, E.D Mao & P.L Li
J.Z Zhang, Y.X Hu, P Liu & Z.P Tian
Research on the optimization of the numerical control machine in engraving 311
X.-Y Liang, J Zheng & S Wang
X.H Zhang
The design of the truss-type floating raft system and study of its vibration
Y.Y Fang, Y.Y Zuo, K.J Mao & Z.W Xia
W Fan, H Lu, Y.Q Zhang, H Ling, Y.X Niu & M Duan
Trang 9Aerospace science and technology
The research of reliability of D subminiature connectors coupling in assembly
W Zhang, Y.G Liu, Y.E Wei, D.M Wang & J Wang
Mechatronics
Navigation of autonomous ground vehicles in cluttered and unknown environment 351
L.W Zhang & L.J Zhang
The design of a multiple hydraulic components test stand system based on mixed
J.G Yi & S.W Ju
Computer science and information technology
Research on interface circuits and calibration algorithms for resistive touch screens 367
C.L Tan, H.D Lei & Y.T Ye
C.J Xu
X Zhou & H.-Y Zhao
A solution of information integration and service sharing in aerospace TT&C systems 385
F Guan
Exploitation and realization of 3D virtual scene based on DirectX 11 technology 391
Q Yuan & H Zhang
L.M Ye & Y Zhu
Graphics, visual and image analysis
An extension of the quartic Wang–Ball closed curves with a given tangent polygon 409
C.W Wang & H Chen
Y Zhao & E Wei
Monitoring and communications
A study of an online dynamic workload prediction algorithm in the cloud environment 441
Y.Q Wang & C.X Fan
Y.Y Wang, X.D Lv & Q Hu
Trang 10An intensive study and experiment on the characteristics of NSGA-II 455
Q Yuan & H Zhang
C Luo
Signal processing
Y Chen & X Li
Z.J Meng, S.Y Huan & Y.T Ji
Fuzzy comprehensive evaluation
Aquifer water yield capacity evaluation using fuzzy evaluation-comprehensive
K Xu & Z Wei
Applied electrochemistry and analytical chemistry
The influence of Al foil current collectors on electrochemical properties
J.C Wang, W He, X.D Zhang, Y.K Hou, Z.L Zhang & H Guo
Determination of imidacloprid, carbendazim and acetamiprid residues in dried
L Lin, M.Y Wang, L.L Liu & C.L Yang
Y.B Zha, C.L Yang, J.Z Ye, X.F Wang, L Lin, S.D Zeng, Y.Q Huang & Y.P Su
Geosciences
Evaluation of groundwater quality in water source areas of a mining area
W.C Wang, J.W Zhao, P Fu, B.S Liang & Y Chen
Modern industrial technology
Y.Y Guo & J Zhang
An analysis of the influential factors of the choice of the pattern of ordering
X Sun, H.H Dong, A.L Huang, Y.F Yang, Y Qin & L.M Jia
L Wang
Y Li
Study on the technical applications of museum interactive display from spectators’
behavioral experience perspectives—an example from Shanghai Science
J Zhang & Y.Y Guo
Trang 11Research on the selection problem of back-up suppliers in the crisis of supply
Z.H Zhang & Q.L Gao
A study on the state of the art and effective implementation of MOOC based
R Xu & Q.L Zhan
Power system and its automation
Simulation and experimental study of the three-phase three-legged transformer
D Xia
H.X Wu
Optimizing battery capacity configuration for a photovoltaic micro-grid system 585
B.L Ouyang, Z Li, Y.Q Wang, L Wang, Y.Y Sun & Y Ma
Trang 12Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang (Eds)
© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6
Preface
Nowadays, more and more experts and scholars are paying attention to Machinery,
Materi-als Science, Electrical Engineering, Electronics Engineering, Control and Automation,
Wire-less Communications and Networks and all fields related to Engineering It is very important
to combine these together from the angle of theory and practice in the field of industrial
engineering The 2016 6th International Conference on Machinery, Materials Science and
Engineering Applications (MMSE 2016) will provide a good platform once again for
scien-tists and engineering managers to exchange their thoughts and cooperation We will have two
important forms to hold this international conference: Specialist reporting and Group
report-ing, to discuss and share the newest important academic thought and academic achievements
in Advanced Engineering Materials, Electrical Engineering and Automation Technology,
Applied Mechanics and Aerospace Science and Technology and others related topics
We will have more than 100 domestic and overseas representatives attending this
interna-tional conference Here, I’d like to express my sincere gratitude to those leaders, Colleges and
Universities, Research Institutes, Companies and all representatives, in appreciation of your
great support
Thank you!
Best wishes for successful work during this conference
MMSE 2016Oct 2016
Trang 14Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang (Eds)
© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6
Committees
EDITED BY
F Lei, Q Xu & G.D Zhang
CO-SPONSORED BY
Wuhan University of Science and Technology, China
Hubei University, China
Dr G.D Zhang, Wuhan University of Science and Technology, China
Prof Q Xu, Huddersfield University, UK
HONORARY CHAIR
Dr Andrianov Nikolay, Russian Academy of Sciences, Russia
Dr L Wang, China Mechanical Engineering Society, China
PROGRAM CHAIR
Prof Gwan Hyoung Lee, Yonsei University, Korea
Prof Hyung-Ho Park, Yonsei University, Korea
Prof Yu, Jung-Lang, Fu Jen Catholic University, Taiwan
INTERNATIONAL AND LOCAL SCIENTIFIC COMMITTEE
Dr Z.Y Lu, Huddersfield University, UK
Dr Z.M Zhang, Wayne State University, USA
Dr Urszula Forys, University of Warsaw, Poland
Dr A.H Xia, The University of Melbourne, Australia
Dr Chih-Hsing Chu, National Tsing Hua University, Taiwan
Prof Nisar Ahmed Memon, Mehran University of Engineering & Technology, Pakistan
Trang 15Dr Manzoor Iqbal Khatak, University of Balochistan, Pakistan
Prof G Feng, City University of Hong Kong, Hong Kong
Prof X.p Li, National University of Singapore, Singapore
Prof George Q Huang, University of Hong Kong, Hong Kong
Dr Wong Wai-on, Hong Kong Polytechnic University, Hong Kong
Dr Paolo Lugli, TU-Munich, Germany
Dr W.J Li, City University of Hong Kong, Hong Kong
Dr Stephen Goodnick, Arizona State University, USA
Dr Seiji Samukawa, Tohoku University, Japan
Dr Jianmin Xiong, Hubei University, China
Dr W.C Chen, Hubei Mechanical Engineering Society, China
Dr A.P Liu, China University of Geosciences, China
Dr H.M Zhou, Huazhong University of Science and Technology, China
Prof J.X Li, Wuhan Polytechnic University, China
Dr M.C Ye, China University of Geosciences, China
Prof Sh.M He, China University of Geosciences, China
Dr X.J Wang, Wuhan University, China
Prof H.B Li, Wuhan University, China
Prof Shengwu Xiong, Wuhan University of Technology, China
Prof J Yang, Wuhan University of Technology, China
Prof P Bo, China Agricultural University, China
Prof L Fen, Ningxia University, China
Prof M.Y Zhang, Sui Hua University, China
Prof Nurbaj Abdushalik, Xinjiang University, China
Trang 16Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang (Eds)
© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6
Introduction
We are very glad to invite you to take part in the 2016 6th MMSE, Wuhan, China on
Oct. 28–30 2016 It will bring you an unexpected harvest In the future, you may be a member
of our big family Therefore, it will be a good chance for you to make friends in academia
The 2016 6th International Conference on Machinery, Materials Science and Engineering
Applications (MMSE 2016) extends its sincere welcome to you to attend it MMSE 2016 is a
leading annual conference for all researchers home and abroad
With the rapid development of Machinery, Materials Science and Engineering
Applications, researchers in all fields begin to discuss some new ideas connected with
mechanical engineering and materials science In this conference, the author(s) can put their
focus on Advanced Engineering Materials, Advanced Manufacturing and Automation
Tech-nology, Applied Mechanics and other related Engineering topics This Conference will
pro-vide a valuable opportunity for researchers, scholars and some scientists to exchange their
ideas face to face together The object is to strengthen national academic exchanges and
cooperation in the field, promote the rapid development of machinery, materials science and
engineering applications, effectively improve China’s machinery, materials science and
engi-neering applications in the field of academic status and international influence and play an
active role to reduce the distance between domestic related and world-class disciplines
The conference is sponsored by Wuhan University of Science and Technology,
co-sponsored by Hubei University, University of Huddersfield, UK, University of Teesside,
UK, University of Nottingham, UK, Worcester Polytechnic Institute Dong-Eui University,
Korea, Hubei Mechanical Engineering Society, and co-sponsored by Chinese Mechanical
Engineering Society
All accepted papers of the 1st, 2nd, 3rd, 4th and 5th International Conference on Machinery,
Materials Science and Engineering Applications have been indexed by EI successfully
Here, on behalf of MMSE 2016, we appreciate our publisher: CRC Press/Balkema
With your support and help, MMSE will be more successful in the future!
With our warmest regards and all the best
MMSE 2016
Trang 18Material science and advanced materials
Trang 20Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang (Eds)
© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6
A PEG-400-etherified 2D resin improves the water absorption
property and thermal stability of silk fibres
Huan Ding & Yong He
Yunshan North Road, Gaoxin Park, New North Zone, Chongqing, China
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
ABSTRACT: The silk (Bombyx mori) fibre has been widely used in the textile industry, due
to its excellent properties such as gloss, softness and light texture It also shows great
poten-tial for biomedical and pharmaceutical applications However, the natural water-absorbing
deficiency of silk fibre is obvious and limits its application in absorbents and medical,
cos-metic, and hygiene products In this study, polyethylene glycol 400 (PEG-400)-etherified 2D
resin (DMDHEU) was utilised to graft silk fibre (referred as grafted silk) to make up for the
insufficiency of natural silk The water absorption and contact angle analysis results revealed
that grafted silk has better water absorption than the silk fibre The morphological
struc-ture of grafted silk observed by using Scanning Electron Microscopy (SEM) reveals more
tightly packed fibres when compared to the silk fibre And also, the distribution of
PEG-400-etherified 2D resin is less uniform than the sericin distribution on the surface of the silk
fibre The stress–strain curves evaluated by using Dynamic Mechanical Analysis (DMA)
indi-cated that the degree of polymerisation of grafted silk is higher than that of the silk fibre
Dif-ferential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) results showed
that both the decomposition temperature and thermal stability of grafted silk are higher than
those of the silk fibre Our results suggested that PEG-400-etherified 2D resin could improve
the water absorption and thermal stability properties of the silk fibre effectively
1 INTRODUCTION
The cocoon of silkworm, Bombyx mori, is made of natural fibre that is composed of proteins
stored in the middle/rear silk gland of the silkworm and discharged through the anterior duct
and spin on the fifth instar Two kinds of silk proteins have been identified as the major
com-ponents of silk: fibroin, which is a fibrous protein composed of a heavy chain, a light chain
and a glycoprotein linked by disulfide bonds and sericin, which serves as an adhesive to bind
fibroin into the fibre [1] Silk fibres have been widely used in the textile industry for
centu-ries and are priced for their gloss, softness and light texture, among other characteristics In
recent years, although the increasing popularity of various synthetic polymers attracted
sig-nificant attention, silk fibre is still an interesting natural material due to its superior strength
and toughness, biocompatibility, and biodegradability The amino acid components in silk
proteins play an important role in its chemical modification Serine, threonine, aspartic acid
and glutamic acid are the main components of sericin [2] Therefore, the silk fibre can be
Trang 21chemically modified through its amino acid side chains to alter its properties Moreover, the
sericin protein is useful because of its oxidative resistance, antibacterial activity, UV
resist-ance, and capacity for blending with other macromolecular materials, including artificial
polymers, to produce materials with improved properties [3]
Recently, the use of traditional composites made of glass, aramid or carbon
fibre-rein-forced plastics has come under increasing scrutiny due to growing environmental awareness
Thus, in the interest of protecting the environment, biocomposites composed of
biodegrad-able polymers for matrix and natural fibres reinforcement have attracted substantial interest
in composite science [4] Among biodegradable polymers, Polyethylene Glycol (PEG) has
received particular attention in academics and industry PEG is a polymerisation product of
glycol and ethylene oxide catalysed by sodium or potassium hydroxide [5] It is a non-toxic,
hydrophilic, biocompatible, and biodegradable polymer, and is one of only a few synthetic
polymers approved by the FDA for internal consumption and injection in a variety of foods,
cosmetics, personal care products and pharmaceuticals It has also been used in a wide range
of biomedical applications [6] A number of PEG-based technologies have been developed
in commercial, therapeutic, research, and diagnostic fields [7] It is thus a desirable and
environmental-friendly substitute for the conventional chemical textile fibre treatment
rea-gents In the present study, we used PEG-400-etherified 2D resin to graft silk fibre, in order
to improve the water absorption of silk fibre, and thus created a novel and fully
biodegrad-able biocomposite silk We investigated the relevant properties of silk fibre and grafted silk
by means of different assays and methods such as the Water Absorption assay, Dynamic
Mechanical Analysis (DMA), Thermogravimetric Analysis (TGA) and Differential
Scan-ning Calorimetry (DSC) These results indicated that the water absorption property and
thermal stability of grafted silk have been significantly enhanced This innovative silk could
potentially be used in the fields of cosmetic materials, tissue engineering and health-related
products
2 MATERIALS AND METHODS
2.1 Materials
Silk fibre from the silkworm (Bombyx mori) was supplied by Xinghang Xi (State Laboratory
of Silkworm Genome Biology, Southwest University, Chongqing, China) Analytical grade
PEG-400 was purchased from YuBei new Asia co LTD (Chongqing, China) 2D resin was
obtained from Founder Chemical Corporation (Chengdu, China) MgCl2•6H2O was
pur-chased from Sangon Biotech Co LTD (Shanghai, China) All other reagents and chemicals
were of analytical grade and used without further purification All water used in these
experi-ments was distilled
2.2 Preparation of silk grafted by PEG-400-etherified 2D resin
The bath method and the second baptist two rolling production process were adopted to graft
silk fibre First, PEG-400 was accurately weighted, added to a certain amount of water, and
dissolved by using a magnetic stirrer (HJ-5) at 1400 rpm at room temperature MgCl2•6H2O
and 2D resin were then added and thoroughly mixed by using a magnetic stirrer to create the
grafting solution Second, to limit swelling and increase its specific surface area, silk fibre was
soaked in water at 60°C for 10 min Third, the swollen silk fibre was immersed in grafting
solution at room temperature for 20 min, removed and drained And then, the fibre was
re-immersed back in the solution, heated and incubated at the desired temperature for 30 min,
removed and drained again The silk was pre-baked for 2 min in a blast oven (DHG-9145 A)
at 90°C, immediately transferred to another blast oven pre-heated to 130°C and baked for 3
min Finally, the grafted silk was washed three times with water at 40°C, dried at room
tem-perature and stored at room temtem-perature
Trang 222.3 Water absorption assay
To calculate the water absorbency of silk fibre and grafted silk fibre, the dry weight was
sub-tracted from the weight of the silk fibre after it was immersed in and saturated with water
This number was then divided by the dry weight according to equation (1):
Q (G G −G G ) )/G1 G *100% (1)where
Q is the water absorption (%)
G1 is the dry weight, g;
G2 is the saturated wet weight, g
2.4 Contact angle calculation
Because a single silk fibre is a thin cylinder, it is very difficult to accurately measure the
con-tact angle of an individual fibre by using planar technology Therefore, BJ Carroll and
Yam-aki have proposed the drop shape method In this method, the shape of the droplet hanging
on the fibre was observed, and the contact angle was calculated based on the Young–Laplace
equations [8,9]
As shown in Fig 1, the equilibrium condition of the droplet surface, ignoring the effect of
gravity, is the additional pressure (ΔP) throughout the surface of the droplet, which is a fixed
value By using the Young–Laplace equation, the following can be obtained:
where
R1 and R2 are the droplet surface curvature radii at a point and
r is the surface tension
According to Fig 1, we can obtain the following equation via integration:
−( ) ( )=( ++ ) ( ) ) ) ( )) ( ))////⎡⎣⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡⎡( ( ( − )( )( )( − )⎤⎦⎤⎤1 2// (3)
In the above equation:
α = (x2cosθ – x1) / (x2 – x1cosθ)
We can use the boundary conditions (x = x1, z = 0; x = x2, and z = L/2) of equation (3) to
calculate θ This method of measuring θ reveals the degree of hydrophilicity of some
materi-als Generally speaking,
Figure 1 Simulation diagram of the liquid droplet profile.
Trang 231 When θ is between 30° and 120°, a matcand a smaller θ value indicates a more absorbent
material; when θ < 0°, a material is defined as a super-absorbent;
2 When θ >120°, a material is defined as hydrophobic;
3 When θ >150°, a material is defined as super-hydrophobic
2.5 Morphology observations
Morphology was observed by using a JSM-6510 LA analytical Scanning Electron
Micro-scope (SEM, Japan) Micrographs of silk fibre and grafted silk were acquired at a high
vac-uum and a voltage of 20 kV Before morphological observation, SBC-12 small ion sputtering
was used to gild all samples All samples were coated at a 6~8 mA current for 80 s, which
created about 10 nm coating of gold
2.6 Determination of relative elements
Since JSM-6510 LA analytical SEM and Elemental Analysis (EDS) software are integrated
into a single instrument, elemental analysis was performed with INCA Oxford software by
directly collecting and analysing the SEM image
2.7 Quasi-static tensile test
A quasi-static tensile test was performed by using a DMAQ800 (TA Instruments, USA)
for all mechanical testing under atmospheric conditions (25°C, RH < 40%) Specimens
were loaded into the tension clamp and quasi-static tensile tests were conducted in DMA
in controlled-force mode The force-ramp rate was 0.1 N/min for each subject fibre The
force–displacement curves were recorded Cross-sectional area data were derived from
SEM observation The cross-sectional area was calculated from Eq (4) on the basis of
shape anisotropy in a procedure described elsewhere [10–13] and was used to rescale
the associated force–displacement curves to obtain the stress–strain curves presented in
Fig. 6 And then, the engineering stress–strain curves were analysed by using Universal
V4.5 A TA instrument software Due to potential dispersion in the experimental data, ten
specimens of each type were measured under the same conditions and the results were
averaged
We obtained the initial diameter and cross-sectional area from the experimentally
deter-mined diameter values after SEM observation by using the following equation:
where D0 and D are the initial and final diameters, respectively;
L0 and L are the initial and final sample lengths, respectively
Eq (4) assumes that the volume of the sample remained constant during the tensile test
[11–13]
2.8 Evaluation of thermal properties
The effect of PEG-400-etherified 2D resin on the melting and decomposition behaviour of
silk fibre was investigated with DSC by using a DSC Q20 machine (TA Instruments, USA)
1~5 mg of each sample was sealed in an aluminium crucible and scanned from 30 to 500°C
at 10°C/min The protective nitrogen gas flow rate was 50 ml/min The thermal behaviour
of the silk fibre and grafted silk was evaluated with the corresponding Universal V4.5 A TA
instrument software TGA analysis was performed with a Q50 TGA (TA Instruments, USA)
1~10 mg of each sample was heated from 40 to 800°C at a rate of 10°C/min at a protective
nitrogen gas flow rate of 50 ml/min The thermal behaviour of the silk fibre and grafted silk
was determined by using Universal V4.5 A TA instrument software
Trang 242.9 Fourier transform infrared spectroscopy (FTIR) assay
A Nicolet iN10 FTIR spectrometer with an MCT-A nitrogen-cooled detector (Thermo
Fisher Scientific, USA) was used for infrared spectra acquisition Spectra were acquired at
a 4 cm–1 resolution from 675 to 4000 cm−1 Static spectra were obtained from an average of
64 scans at a 2.5317 cm–1 mirror speed All spectral operations were executed and a principal
component analysis was performed afterwards by using Nicolet OMNIC software Infrared
spectra were used to investigate the chemical conformation and miscibility of silk fibre and
grafted silk in the spectral region of 600–2500 cm−1
3 RESULTS AND DISCUSSION
3.1 Water absorption
Water absorption is a key factor for silk fibres used in many biomaterials, including
disin-fecting wipes, wound dressings, haemostatic stickers, bandages, and absorbent pads It is
clear in Fig 2 that the water absorption of grafted silk was significantly higher than that
of silk fibre The water absorbency of grafted silk increased by 126.43% when compared to
silk fibre, suggested that grafting with PEG-400-etherified 2D resin is a simple, effective,
efficient and green method to improve the water absorption of silk fibres when compared
with copolymerisation or blending In addition, we observed that the colour of grafted silk
was whiter than silk fibres, and it did not yellow during long-term storage at room
tempera-ture Numerous studies [14–18] have indicated that exposure of tryptophan and tyrosine
to UV radiation (~300 nm) can produce fluorescent derivatives However, in this study,
long-time storage at room temperature did not cause grafted silk to yellow It was likely
that tryptophan and tyrosine of silk fibre reacted with PEG-400-etherified 2D resin
dur-ing the graftdur-ing reaction Namely, the carboxyl groups of tryptophan and tyrosine reacted
with hydroxyl groups of PEG-400-etherified 2D resin in an esterification reaction These
results demonstrate that this is a simple, convenient and environmentally friendly method
for modifying silk fibres to improve their properties, such as water absorption, colour
bril-liance, and durability
3.2 Contact angle
As seen in Table 1, silk fibre, with a contact angle of 167.6°, is a hydrophobic fibre After
grafting with PEG-400-etherified 2D resin, the contact angle decreases from 167.6° to 73.3°,
converting this hydrophobic fibre into hydrophilic fibre and improving the water absorption
property of silk fibres It is very helpful in applying silk fibre in absorbents, medical,
cos-metic, and hygiene fields, such as disinfecting wipes, wound dressings, haemostatic stickers,
bandages, and absorbent pads, among others
Figure 2 Water absorption of silk fibre and grafted silk.
Trang 25Figure 3 Contact angles of raw and grafted silk.
Table 1 Contact angles of raw and grafted silks.
Sample Contact angle of the left Contact angle of the left
Figure 4 SEM images of raw and grafted silks.
3.3 Morphology
While it is important to understand the structural and morphological changes that occur
during grafting, it is equally important to acquire accurate quantitative knowledge of the
changes in the mechanical properties of silk under load, if we aim to understand and
repro-duce the desirable properties of silk [19] Fig 4 shows the morphology of silk fibre and
grafted silk, and the surface morphology of the silk fibre and grafted silk are shown in Fig 4
A and B, respectively It can be seen in Fig 4 A that sericin is a bonding agent between fibres
that maintains the spatial structure of the silk fibre Sericin is unevenly distributed on the
sur-face of the silk fibre due to its viscosity The morphology of grafted silk is very similar to that
of the silk fibre Small differences are evident in the following two aspects First, grafted silk
is more tightly packed than the silk fibre This may be caused by the interactions between the
PEG-400-etherified 2D resin and silk fibre Second, polymer PEG-400-etherified 2D resin
in grafted silk is distributed somewhat less uniformly than the sericin on the surface of silk
fibre When comparing Fig 4 A and B, it is clear that grafted silk has maintained more of its
natural characteristics in the presence of crosslinking reactions In particular, there is no
dif-ference in texture between the two materials Therefore, this processing method has improved
the properties of silk without affecting its desirable natural characteristics
3.4 Relative elemental content
Changes in the relative elemental content of silk fibre and grafted silk may be reflected in
the occurrence and degree of reaction When comparing Tables 2 and 3, the nitrogen content
in silk fibre (34.05%) is higher than that of grafted silk (22.18%), but the oxygen content is
lower (65.95% for silk fibre and 77.82% for grafted silk) This is primarily due to the
intro-duction of the PEG-400-etherified 2D resin, because it contains many hydroxyl groups This
Trang 26Figure 5 Elemental analysis results of raw silk and grafted silk.
Table 2 Calculation results of raw silk elements.
Element
Line type
Apparent concentration
Intensity correction K ratio wt%
Standard samples
Apparent concentration
Intensity correction K ratio wt%
Standard samples
also suggests that the PEG-400-etherified 2D resin interacts with silk fibre through
chemi-cally modified amino acid side chains
3.5 Mechanical properties
The mechanical properties tests used in this paper applied tensile stress to the samples
and measured strain as the dimensional response We chose stress rather than strain as the
control variable because of biological function When a silkworm falls, the radial/dragline
threads have to take up the load rather than respond to an applied dimensional strain
Indeed, many natural processes are often driven by ‘stress’ Thus, we believe that stress is
more important than strain as an evolutionary driver for the structure and properties of
natural materials [19] As seen in Fig 6, the two curves follow essentially a same trend
Relative to silk fibre, the breaking strength and elongation of grafted silk at the point
of breakage was increased This assessment of morphological characteristics has
demon-strated that the degree of polymerisation for silk fibre can be improved by grafting with
PEG-400-etherified 2D resin, while grafting strengthens intermolecular forces due to the
viscous flow resistance of PEG-400 This result is consistent with the conclusions of
Jian-nan Wang and Jiayong Sheng [20, 21] These authors concluded that the initial modulus
of silk fibre was primarily determined by the non-crystalline arrangement between
mol-ecules The magnitude of the binding force between molecules is smaller and the molecular
regularity is lower, which increases the void volume within the material The void volume
provides the motor-unit activity space, increases the molecular activity and lowers the
Trang 27ini-Figure 6 Stress–strain curve.
tial modulus After grafting with PEG-400-etherified 2D resin, the intermolecular forces
of the silk fibre is strengthened, the molecular structure becomes closer, the molecules are
more orderly, and the activity of peptide chains and segments is blocked Overall,
PEG-400-etherified 2D resin grafting does not affect the mechanical properties of the silk fibre,
and to some extent can improve its strength
3.6 Thermal property analysis by using TGA and DSC
3.6.1 TGA analysis
TGA is an effective approach for the evaluation of the thermal stability of polymeric
mate-rials It is also useful for the quantitative determination of the degradation behaviour and
composition of fibres and matrix in a composite According to the results of Guanfeng Liu
and Xiaoling Wang, the Differential Thermal curve (DTA) of the silk fibre contained peaks
at 70°C, 310 and 395°C, with nearby thermal effects The first peak was caused by the release
of water in the form of physical or chemical adsorption The second peak was believed to
be primarily caused by the decomposition of non-crystalline or quasi-crystalline regions of
fibroin and sericin The third peak occurred due to the decomposition of crystallised fibroin
and sericin molecules
As shown in Fig 7, the TGA curves of the silk fibre and grafted silk passed through
three phases upon heating from 0°C to 800°C The decomposition temperature of each
phase and the final weight loss is shown in Table 4 As shown in Fig 7, the first weight-loss
phase for grafted silk began at 47°C The dotted grey curve in Fig 7 demonstrated that
very little weight loss occurred in the first phase At temperatures below 100°C, the weight
loss of grafted and silk fibre was 6% and 0%, respectively The initial weight loss was due to
the evaporation of water from grafted silk This significant difference indicates that
graft-ing with PEG-400-etherified 2D resin improved the water absorption of the silk fibre, while
there was no significant weight loss at the 100~200°C temperature change The
decomposi-tion of grafted and silk fibre starts at 227.8°C and 275.07°C, respectively These results are
consistent with the work of Yongqing Zhao [22] and Han Zhang [23], who demonstrated
that the silk fibre began to lose weight significantly near 250°C and lost weight almost
quickly at a temperature approximately equal to 309°C In this phase, the weight loss of
the silk fibre and grafted silk was 23% and 6%, respectively, in accordance with the first
phase In the final phase, at the temperature range from 429.84°C to 800°C, there was
lit-tle difference in thermal stability between the silk fibre and grafted silk, because PEG-400
decomposed at approximately 238°C We conclude that grafting with PEG-400-etherified
2D resin can improve the thermal stability and reduce the weight loss of the silk fibre And
also, grafting with PEG-400-etherified 2D resin does improve the water absorption
prop-erty of the silk fibre
Trang 28Table 4 TGA results of the raw silk and grafted silk composites.
T1, T2 and T3: the temperatures at which first, second, and third stage decompositions begin,
respectively Tg: glass transition temperature.
Figure 8 DSC curves of the silk fibre and grafted silk.
Figure 7 TGA curves of silk fibre and grafted silk.
3.6.2 DSC analysis
Fig 8 showed the DSC curves of the silk fibre and grafted silk Previous DSC studies
had indicated that the silk fibre began to dehydrate at 100°C and decomposed at 305°C
In this study, the melting behaviour and decomposition temperature of both materials were
investigated and all peaks for decomposition and enthalpy are listed in Table 5 The results
demonstrated that grafted silk produced a significant exothermic peak at 238°C that did
not appear in the DSC curve of the silk fibre This exothermic peak corresponded to the
decomposition temperature of PEG-400 and was consistent with the results of TGA Peaks
at 91.99°C and 318.24°C correspond to the decomposition temperatures of water and silk
fibre, respectively These differences were reflected in the following two ways: (1) as shown
in Fig 8, the enthalpy change for grafted silk, at 91.99°C, was greater than that of silk
fibre This observation explained the fact that the water absorption of grafted silk was
higher than that of the silk fibre; (2) the enthalpy change for grafted silk at 318.24°C was
lower than that of the silk fibre This conclusion is consistent with the TGA results
pre-sented above
Trang 29Table 5 DSC results of the raw silk and grafted raw silk composites.
Sample Tm1 (°C) ΔHm1 (J/g) Tm2 (°C) ΔHm2 (J/g) Td (°C) ΔHm3 (J/g)
Tm1: initial melting temperature ΔHm1: initial enthalpy of fusion.
Tm2: the decomposition temperature of raw silk ΔHm2: enthalpy of fusion of raw silk.
Td: the decomposition temperature of PEG ΔHm3: enthalpy of fusion of PEG.
Table 6 Silk amide bond absorption peaks.
Structure type
Amide I [ νC = O(cm −1 )]
Amide II [ δN = O(cm −1 )]
Amide III [ νC =N(cm −1 )]
Amide V [ γN = H(cm −1 )]
Random
conformation
Figure 9 FTIR spectra of silk fibre and grafted silk.
Both TGA and DSC analysis arrived at the same conclusion that grafting with
PEG-400-etherified 2D resin can improve the water absorption property and thermal stability of
the silk fibre
3.7 FTIR analysis
Silk fibre from B mori is composed of proteins containing different types of amide bonds
with specific infrared absorption peaks and structures and the FTIR profile of silk fibre has
been extensively studied [7,24] Table 6 demonstrated that silk fibre had distinct amide I,
amide II, amide III and amide V bands [25]
Fig 9 showed that silk fibre possessed an irregular conformation for amide I and amide II,
at 1673.91 cm–1 and 1554.74 cm–1, respectively These two amide bands transformed into β-sheet
conformation at 1637.03 cm–1 and 1527.81 cm–1, respectively, after grafting with
PEG-400-ether-ified 2D resin However, the conformation of amide III and amide V remained unchanged This
suggested that grafting improved the structural stability of the silk fibre In studies by Parag
Kolhe and Rangaramanujam M Kannan [7], characteristic absorption bands for PEG were
observed at 1280 cm–1, 947 cm–1 and 843 cm–1 In our results, PEG absorption peaks appeared
at 1280 cm–1, 944.52 cm–1 and 843 cm–1 Furthermore, an absorption peak for hydroxyl groups
Trang 30appeared at 1065.23 cm This is consistent with the EDS analysis results and confirms that
PEG-400-etherified 2D resin did interact with silk fibre In short, it can be seen that grafting
with PEG-400-etherified 2D resin can improve the structural stability of the silk fibre
4 DISCUSSION AND CONCLUSIONS
Silkworm silk fibre is a renewable protein biopolymer that has been proven to be valuable
in the textile industry and also for medical and cosmetic applications because of its
supe-rior mechanical properties and bio-compatibility Chemical modification is essential for
the creation of an ideal fibre because some properties of silk fibre limit its performance
in some applications In this paper, we present the modification of silk fibre by grafting
with PEG-400-etherified 2D resin to improve its water absorption property and thermal
stability Mechanical and theoretical analyses have demonstrated that, after grafting, the
mechanical and thermal stability of silk fibres were improved FTIR spectroscopy results
also demonstrated that grafting increases its structural stability Overall, our results support
the following conclusions: (i) grafting with PEG-400-etherified 2D resin improves the water
absorption property of silk fibre 2D resin is a very effective cross-linking agent; (ii) grafting
improves whiteness and does not affect the texture of the silk fibre; (iii) grafting with
PEG-400-etherified 2D resin improves the mechanical properties and flexibility of the silk fibre;
(iv) TGA, DSC and FTIR spectroscopy analyses demonstrate that the thermal and structural
stability of the silk fibre also have been improved by grafting with PEG-400-etherified 2D
resin These results taken together suggest that grafting with PEG-400-etherified 2D resin
is a better method for improving the water absorption property of silk fibres than blending
or copolymerisation Furthermore, this method improves the structural and thermal
stabil-ity of silk fibres, while retaining their natural performance In short, grafting of silk fibre
with PEG-400-etherified 2D resin is a fast, simple, low-cost, effective, and environmentally
friendly modification process
REFERENCES
[1] M Mondal, K Trivedy and S Nirmal Kumar 2007 The silk proteins, sericin and fibroin in
silk-worm, Bombyx mori Linn-a review Caspian J Env Sci, 5: 63–76.
[2] Norihisa Kato, Seiji Sato, Atsushi Yamanaka, Hideyuki Yamada, Naozumi Fuwa and Masakazu
Nomura 1988 Silk Protein, Sericin, inhibits lipid peroxidation and tyrosinase activity Biosci
Bio-technol, 62: 145–147.
[3] Yuqing Zhang 2002 Applications of natural silk protein sericin in biomaterials Biotechnology
Advances, 20: 91–100.
[4] A.K Mohanty, M Misra, G Hinrichsen, Biofibres 2000 Biodegradable polymers and
biocompos-ites: An overview macromolecular materials and engineering 276: 1–24.
[5] Zhexun Zhao 1993 Preparation of PEG and it’s Application Commerce reported of Tianjin
Uni-versity 20:18–21.
[6] Narayan Bhattarai, Hassna R, Ramay, Jonathan Gunn, Frederick A Matsen, Miqin Zhang 2005
PEG-grafted chitosan as an injectable thermosensitive hydrogel for sustained protein release
Jour-nal of Controlled Release 103: 609–624.
[7] Kolge P, Kannan RM 2003 Improvement in ductility of chitosan through blending and
copo-lymerization with PEG: FTIR investigation of molecular interactions Biomacromolecules
4:173–180.
[8] Carroll B J 1976 The accurate measurement of contact angle, phase contact areas, drop volume,
and laplace excess pressure in drop-on-fiber systems Journal of Colloid and Interface Science, 57:
488–495.
[9] Jun Ichi Yamaki, Yuzo Katayama 1975 New method of contact angle between monofilament and
liquid Journal of Applied Polymer Science 19: 2897–2909.
[10] Ping Jiang, Huifen Liu, Changhe Wang, Lingzhi Wu, Jianguo Huang, Cong Guo 2006 Tensile
behavior and morphology of differently degummed silkworm (Bombyx mori) cocoon silk fibres
Materials Letters 60: 919–925.
Trang 31[11] H Somashekarappa, V Annadurai, Sangappa, G Subramanya 2002 Materials Letters, 53:
[14] Wenzheng Luo, Yunfang Feng 1990 Studies on the mechanism of silk yellowing by ultraviolet
irradiation Journal of Zhejiang Silk Engineering College 7: 52–57.
[15] Masuhiro Tsukada, Tsuneo Imai, Giuliano Freddi, Subasini Lenka, Nobutami Kasai 1998
Graft-ing of vinyl monomers onto silk usGraft-ing redox systems YellowGraft-ing of silk Journal of Applied Polymer
Science 69: 239–246.
[16] Yoshikuni Yanagi Yoshiyuki Kondo Kiyoshi Hirabayashi 2000 Deterioration of silk fabrics and
their crystallinity Textile Research Journal 70: 871–875.
[17] Detai Ye, Baoyong Jiang 1998 Research on silk yellowing caused by ultraviolet irradiation Silk
Monthly 9–12.
[18] Jianzhong Shao, Jinqiang Liu, Jinhuan Zheng, C M Carr 2002 X-ray photoelectron spectroscopic
study of silk fibroin surface Polymer International 51: 1479–1483.
[19] Juan Guan, David Porter, Fritz Vollrath 2012 Silks cope with stress by tuning their mechanical
properties under load Polymer 53:2717–2726.
[20] Jiannan Wang, Yuyue Chen, Honggen Yi, Jiayong Sheng 2003 The Research of Silk Fiber’s
Mor-phological Structure and Performance When it Dissolves Slightly in Calcium Solutions Acta
Seri-cologica Sinica 29:173–176.
[21] Jiayong Sheng, Yuyue Chen 1999 Research on the assemble structures of the bulky mulberry silk
filament Acta Sericologica Sinica 25: 46–52.
[22] Yongqing Zhao, Hongyan Cheng, Kin-Tak Lau, Cailing Xu, Dandan Zhao, Hulin Li 2010
Silk-worm silk/poly (lactic acid) biocomposites: Dynamic mechanical, thermal and biodegradable
properties Polymer Degradation and Stability 95: 1978–1987.
[23] Han Zhang, Jun Magoshi, Mary Becker, Jieyu Chen, Ryuji Matsunaga 2002 Thermal properties
of Bombyx mori silk fibers Journal of Applied Polymer Science 86:1817–1820.
[24] Yongcheng Liu, Zhengzhong Shao, Yuyu Sun, Tongyin Yu 1998 The structure and function of
silk fibroin Polymer Bulletin 3: 17–23.
[25] Guodi Qian, Yuliang Yao 1983 The Application of Infrared Spectar to the Ivestigation of the
Structure of Silk Fiber Suzhou Silk Institute of Technology 4: 26–30.
Trang 32Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang (Eds)
© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6
Selective formation of AlPO4-21 and AlPO4-12 molecular sieves
by microwave technique
Pengmei Chang
Drilling and Production Technology Research Institute of Liaohe Oilfield, Panjin, P.R China
ABSTRACT: AlPO4-12 Molecular Sieves (MS) were also synthesized through the
Micro-wave Technique (MT), using Trimethylamine (TMA) rather than Dimethylamine (DMA) as
the template in the presence of Hydrofluoric acid (HF) XRD, SEM, MAS NMR and
TG-DSC were used to characterize the products synthesized in different conditions The results
indicated that the MT accelerated the crystallization of AlPO4-12 MS, particularly owing to
the release of aluminum species from AlFn complexes and dissolving the impurity The
struc-tural directing effect of the TMA was changed through ion pairing with fluoride ions, leading
to the crystallization of AlPO4-12 rather than AlPO4-21 MS
1 INTRODUCTION
In the early 1980s, a new series of open-framework aluminophosphates (denoted AlPO4-n)
were first prepared by using organic amines as the templates in a hydrothermal synthesis
system Since then, many kinds of AlPO4-n MS with new structures were fabricated through
introducing different organic amines into the synthesis system [1–2] In many cases, most
of AlPO4-n MS could be synthesized in the presence of several kinds of organic templates
For example, AlPO4-21 MS could be synthesized by using ethylamine, DMA or TMA as
the templates [3, 4] More than 20 types of organic amines were applied as the templates
to fabricate AlPO4-5 MS successfully [5] However, there were still some exceptions As
reported previously, AlPO4-12 MS could be synthesized only when the DMA was used as
template [6] Conventionally, AlPO4-n MS were synthesized by time-consuming
hydrother-mal method Microwave irradiation realized efficient internal “in core” volumetric heating
by direct coupling of microwave energy to the molecules that were present in the reaction
mixture, thus leading to the great enhancement of the energy transferring [7] Microwave
irradiation could enhance the crystallization rates of the MS for more than ten times
com-pared to the CHT [8–9] In the case of SAPO-56 MS, uniform hexagonal crystals with AFX
topology were successfully synthesized by the MT at 150°C for 10 min, whereas the similar
crystals could be prepared by using the CHT at 200°C for 96 h [10] In addition to the
reduction in synthesis time, the MT exhibited some significant effects on the improvement
for the purity, uniformity and structures of the MS [11] Gharibeh et al [12] found that the
MT did not only accelerate both the nucleation and growth rates of SAPO-11 MS, but also
afforded more uniform and narrow particle distribution compared to the CHT
Further-more, SAPO-5 and SAPO-34 MS were selectively formed by using the MT or CHT,
respec-tively, of the same gel irrespective of the acidity or the type of the templates [13] The results
demonstrated that microwave irradiation could be used as a special phase selective synthesis
method for some unstable MS
In the current work, the MT speeded up the crystallization of AlPO4-21 and AlPO4-12
compared to the CHT Furthermore, AlPO4-12 MS were successfully fabricated for the
first time by using TMA rather than DMA as the templates with the assistance of HF
Trang 332 EXPERIMENTAL
All of the reactants were commercially available with analytical purity Pseudo-boehmite
(Al2O3), phosphoric acid (H3PO4, 85%, aq.) were dispersed in 40 mL deionized water and
stirred for 1.5 h Simultaneously, hydrofluoric acid (HF, 40%, aq.) was selectively added into
the suspension After that, the TMA was added dropwise into the reaction mixture under
vigorously stirring for another 0.5 h Finally, the molar ratio of the reactants was fixed as
n(Al2O3):n(P2O5):n(TMA):n(HF):n(H2O) = 1.0: 1.25: 1.0: 0~1.0: 100 The suspension was
transferred into Teflon autoclave, which was sealed and placed in a microwave oven The
vessel was heated to 120°C in approximately 2 min and maintained at the temperature for a
predetermined time The microwave power was 400 W at the heating stage For the synthesis
by the CHT, the suspension was loaded in a Teflon lined autoclave and put in a preheated
electric oven at 120°C for a fixed time without agitation All products were separated, washed
for several times and dried in an oven at 100°C for 5 h Finally, the organic templates were
removed by calcination in the muffle at 550°C for 4 h
The crystal structure and crystallinity of the samples were determined by powder X-Ray
Diffraction (XRD, UltimaIV, Rigalcu Co., Japan) using Cu Kα radiation The
morpholo-gies of the products were determined by Scanning Electron Microscopy (SEM, Quanta 200,
Philips-FEI Co., Holland) The thermal decomposition of templates in the MS was detected
by the thermal analysis system (TG-DSC, Q1000, TA Co., USA) The chemical environment
of the products was detected by 19F MAS NMR equipment (AV400, Bruker Co., Germany)
3 RESULTS AND DISCUSSION
The synthesized conditions are shown in Table 1 Fig 1(A) shows the XRD patterns of the
samples listed in Table 1(A) to (D) When the system was heated for 8 h, there was no obvious
diffraction peaks observed in Fig 1A(1), indicating that no crystals formed in this process
Once the synthesized time was prolonged to 12 h, several obvious diffraction peaks appeared
in Fig 1 A(2), which all corresponded well to AlPO4-21 MS with ATV structure (JCPDF No
43-0572) except one peak locating at d = 4.35 Actually, the peak at d = 4.35 could be assigned
to the by-product of aluminum phosphate (JCPDF No 48-0652) The intensity of AlPO4-21
MS diffraction peaks increased steadily by increasing reaction time from 12 h to 48 h, whereas
the peak at d = 4.35 weakened gradually by prolonging the synthesized time and disappeared
at 48 h As a result, pure AlPO4-21 MS with high crystallinity could be obtained after
syn-thesis for a long time by using the CHT Fig 1(B) depicts the XRD patterns of the samples
listed in Table 1(E) to (H) In contrast to the samples synthesized by the CHT, the typical
dif-fraction peaks of AlPO4-21 MS appeared in the curve (1) of Fig 1(B) after synthesis by the
Table 1 Reaction conditions of the samples.
Sample No. n(HF):n(H2O) Time Synthesized method Calcination
Trang 34MT for 10 min The impure peaks at d = 8.37 and 4.35 could be attributed to the un-reacted
Al2O3 and by-product of aluminum phosphate, respectively When the microwave irradiation
time was fixed at 20 min, the peak at d = 8.37 disappeared, indicating that the residual Al2O3
reacted with other reactants absolutely As shown in Fig 1 A curves (2) to (4), the
diffrac-tion peaks of the AlPO4-21 MS grew in intensity as the synthesis time increased When the
microwave irradiation time was prolonged to 60 min, any noticeable diffraction peaks of the
impure phases disappeared, and thus pure AlPO4-21 MS were obtained
Some inhomogeneous crystals with rough surface were observed from Fig 2 In contrast
to the sample D synthesized by the CHT, some clear and perfect AlPO4-21 crystals in the
form of regularly rhombic polyhedron were observed in the sample H, demonstrating that
the MT improved both of the crystallization rate and crystals quality
Fig 3 depicts the XRD patterns of the samples synthesized by using the MT or CHT
with the different usage of HF As shown in the curves (1) of Fig 3(A) and (B), both of the
curves agreed well with the standard XRD pattern of AlPO4-21 MS, indicating that the initial
product synthesized in the absence of HF was AlPO4-21 MS, irrespective of the MT or CHT
used for the synthesis As shown in Fig 3(A), when a slight amount of HF was added into the
synthesis system, only four weak diffraction peaks of the sample I were observed in curve (2)
Similarly, HF was added into the reactants in order to synthesize AlPO4-12 MS by the CHT
Unfortunately, although the molar ratio between HF and H2O was adjusted from 0.5:100 to
1.0:100, only a few of diffraction peaks were observed in curves (2) to (5) of Fig 3(B), which
made it difficult to distinguish the crystal phases in these samples In contrast to the MT,
Figure 1 (A) XRD patterns of the products synthesized by using CH: curve (1) to curve (4)
corre-sponded to the sample A to D (B) XRD patterns of the products synthesized by using the MT: curve
(1) to curve (4) corresponded to the sample E to H.
Figure 2 Displays the SEM images of the sample D and H.
Trang 35AlPO4-12 MS could not be synthesized by the CHT in the presence of HF due to the slow
crystallization rate
The SEM images of the sample H to K As shown in Fig 4(A), when a slight amount
of HF was added into the synthesis system, AlPO4-21 MS with rhombic polyhedral
mor-phologies disappeared absolutely, but quasi spheres aggregated by many nano-sheets were
obtained Once the n(HF):n(H2O) was fixed as 0.5:100, the morphology of the obtained
AlPO4-12 MS was still spheres aggregated by smaller sheet crystals Further increasing the
usage of HF, the obtained AlPO4-12 MS in the form of nano-rods were observed in Fig 4(C)
and (D) It is interesting that the structural transformation from AlPO4-21 to AlPO4-12 MS
accompanied with significant changes on crystal morphologies with the assistance of HF
In order to make clear of the function of HF in the crystallization of AlPO4-12 rather than
AlPO4-21 MS, MAS NMR was employed to detect chemical environment of 19F in the sample
L and R For the pure AlPO4-12 MS (sample H) synthesized by the MT, only one resonance
peak at −118.7 ppm appeared in Fig 5(A), which resulted from F– ions acting as a counterion
Figure 3 (A) XRD patterns of the products synthesized with different usage of HF by using CH:
curve (1) sample H, (2) to curve (5) corresponded to the sample I to L in Table 1 respectively; (B)
XRD patterns of the products synthesized by using the MT: curve (1) to curve (5) corresponded to the
amounts of 0.25, 0.5, 0.75 and 1.0 respectively for 48 h.
Figure 4 SEM images of the products synthesized by using the MT: image (A) to (D) corresponded
to the sample I to L in Table 1 respectively.
Trang 36to TMA+ ions This confirmed that F– ions preferred to balance the counter charge of TMA+
ions rather than coordinate with Al3+ ions in the framework of the AlPO4-12 MS For the
impure AlPO4-12 MS (sample L) synthesized by the CHT, the shoulder at –122 ppm was also
observed in Fig 5(B), which also could be assigned to the complex TMA-F But two peaks at
–140.9 and –177.4 ppm could be assigned to F– ions in the structure of AlF2(OH)4 and AlF6
respectively according to other previous researches [10] The result demonstrated that Al-F
complexes had not been released absolutely after heating by the CHT for one week
4 CONCLUSION
AlPO4-21 MS were successfully synthesized by using TMA as the templates through the
CHT or MT; however, the MT exhibited higher synthetic efficiency in the crystallization
of AlPO4-21 MS with high crystal quality comparing to the CHT Furthermore, AlPO4-12
MS were also synthesized for the first time by the MT, using TMA rather than DMA as the
templates in the presence of HF It can be considered as a technique breakthrough because
previously AlPO4-12 MS could only be synthesized when DMA was used as the templates As
being a thermally unstable crystal phase, the structure of AlPO4-12 MS partially destroyed
during the templates burning process
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synthesis, Zeolites 3, 282–291.
[6] Q.M Gao, S.G Li, R.R Xu, 1997, Synthesis of microporous aluminophosphates (AlPO4-12,
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[8] L Bonaccorsi, L Calabrese, A Freni, E Proverbio, 2013, Hydrothermal and microwave
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characteriza-tion of nano-NaX zeolite by microwave assisted hydrothermal method, Adv Powder Technol 25,
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[11] S.T Yang, J.Y Kim, H.J Chae, M Kim, S.Y Jeong, Wha S Ahn, 2012, Microwave synthesis of
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[13] S.H Jhung, J.S Chang, J.S Hwang, S.E Park, 2003, Selective formation of SAPO-5 and SAPO-34
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Trang 38Machinery, Materials Science and Engineering Applications – Lei, Xu & Zhang (Eds)
© 2017 Taylor & Francis Group, London, ISBN 978-1-138-02957-6
Parameter optimization of forming limited diagram based
on virtual material method
Qiang Yu, Jin Liang & Li-wen Tian
State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering,
Xi’an Jiaotong University, Xi’an, China
ABSTRACT: Studying on the accuracy of forming limited diagram for H340LAD-Z steel
on the platform of dynaform software, virtual material method is used to adjust the value of
exponent in Barlat’s yield surface m, exponent for Swift exponential hardening n, Lankford
parameter r The virtual material parameters are studied in this paper Overall distribution
of uniaxial tensile strain at break test is obtained with XJTUDIC three-dimensional
digi-tal speckle strain measurement and analysis system The results show that the optimal level
parameters can be obtained when m = 4, r = 0.8, n = 0.18 and ultimate displacement relative
error is decreased from 15% to 6.3%
1 INTRODUCTION
Forming Limit Diagram (FLD) is one of the most commonly used criterions for judging
inte-grated performance in sheet metal forming process And it is the technology and judgment
basis for the research and analysis of sheet metal forming limit and the success or failure of
the stamping process [1–4] The material properties of the steel plate are different, and even
the material parameters with same grade may be also different sometimes, thus the results
of finite element analysis are still some errors in the simulation of sheet metal forming [5,6]
Therefore, study on simulation accuracy of finite element software has important theoretical
and practical value in application and development for automobile panel manufacturing
Finite element numerical simulation technology, 3D full field measurement technology
and orthogonal test are used in this paper The optimal parameters of virtual material is
carried out by adjusting the material parameters of exponent in Barlat’s yield surface m,
exponent for Swift exponential hardening n, and Lankford parameter r value The method
can improve simulation prediction accuracy of H340LAD-Z alloy by Dynaform software
and improve the work of die design and tryout process
2 NUMERICAL SIMULATION AND DIE TRYOUT
According to the National Standard GBT 15825.8–2008, 9 groups FLD samples are designed,
the test samples are round with diameter of 180 mm, the width range is from 20 mm to 180
mm, the interval is 20 mm The samples after cupping test tryout are shown in Figure 1 The
limit strain under different strain paths are obtained and complete FLD of tryout can be
carried out [7–9]
Stamping sheet material in this paper is H340LAD_Z with the thickness of 1.5 mm Material
Type 36 in dynaform software library is used as the original material parameters in simulation
And density of material is 7.85 × 103 kg/m3 with Young’s modulus 2.07 × 105 MPa, Poisson
ratio 0.28, yield strength 403 MPa And exponent in Barlat’s yield surface m is 6 with
harden-ing exponent n 0.16, Lankford parameter r 1.0 in the material library of Dynaform software.
According to t national standard size, Finite element model is established as shown in
Fig-ure 2 the movement of the simulation process is divided into two stages: closFig-ure stage and
Trang 39drawing stage For the closure stage, blank holder is static, sheet metal is placed on the blank
holder, and the speed of die moving down is 2500 mm/s until closed with blank holder For the
drawing stage, speed of punch moving down is 3500 mm/s and the binder force is 2 × 105 N
3 ORTHOGONAL DESIGN AND PARAMETERS OPTIMIZATION OF VIRTUAL
MATERIAL
Exponent in Barlat’s yield surface m, hardening exponent n and Lankford parameter r are
selected as test factors called factor A, B, C It assumes that there is no interaction among the
various factors Each factor corresponds to three kinds of test levels, with m = 2, 4, 6, r = 0.8,
0.9, 1.0, n = 0.16, 0.18, 0.20 According to the principle that containing all the factors and the
least number of test times, the L9 (34) 3 factors 3 levels orthogonal table is used, and error
column blank is set The average value differences of the limit strain obtained by cupping test
tryout and simulation from 9 samples are taken as the test index The orthogonal test plan
and results are shown in Table 1
Extremum difference analysis method is used to analyze virtual material parameters
Extremum difference is the difference between the maximum and minimum values of the
test results under different levels The results of extremum difference analysis are shown in
Table 2 Ki represents the means of the i-th factor, and the i-th row of factors corresponding
to excellent levels can be evaluated according to Ki R factors are the differences between
maximum and minimum values at three levels Ri represents the fluctuation of the test due to
the changes of factor level
Factors significance is judged according to its extremum difference iR Deviation of
extremum difference is represented by blank column in orthogonal table If extremum
differ-ence of factor is lower than extremum differdiffer-ence of error, then corresponding significance is
less than the error range From Table 2:
1 Optimal virtual material level: m = 4, r = 0.8, n = 0.18.
2 The influence sequence of factors: n > m > r.
The FLD obtained from cupping test tryout, simulation with original material parameters
from dynaform material library and virtual material parameters are shown in Fig 3
Figure 1 The result of cupping test.
Figure 2 The model of finite element numerical simulation.
Trang 404 EXPERIMENTAL VERIFICATION OF VIRTUAL MATERIAL
The numerical simulations of uniaxial tension process are carried out with the original
mate-rial parameters and virtual matemate-rial parameters respectively The uniaxial tension results
are obtained by XJTUDIC three-dimensional digital speckle strain measurement system as
shown in Fig 4 The experiment process is that the samples are painted with white matte
paint evenly then some black spots are sprayed randomly The uniaxial tension process are
monitored and analyzed by XJTUDIC system Fig 5 shows the rupture samples of uniaxial
tensile experiment True stress-strain curve of uniaxial tensile is obtained as shown in Fig 6
The curve shows that the stress decreased rapidly after it reaches the highest point of the
curve It can be judged that turning point is the breaking point with displacement 16.92
Table 1 Plan and result of orthogonal experiment.
Test No.
Evaluation index
Figure 3 FLD of experiment, original and virtual material.