Electrophoretic deposition of reduced graphene oxide thin films for reduction of cross sectional heat diffusion in glass windows

Original Articlereduction of cross-sectional heat diffusion in glass windows Loo Pin Yeoa,b,1, Tam Duy Nguyena,b,**,1, Han Linga, Ying Leea, Daniel Mandlerb,c, Shlomo Magdassib,c, Alfred

Trang 1

Original Article

reduction of cross-sectional heat diffusion in glass windows

Loo Pin Yeoa,b,1, Tam Duy Nguyena,b,**,1, Han Linga, Ying Leea, Daniel Mandlerb,c,

Shlomo Magdassib,c, Alfred Iing Yoong Toka,b,*

a School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798

b Singapore-HUJ Alliance for Research and Enterprise, NEW-CREATE Phase II, Campus for Research Excellence and Technological Enterprise (CREATE),

Singapore 138602

c Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel

a r t i c l e i n f o

Article history:

Received 15 February 2019

Received in revised form

29 March 2019

Accepted 1 April 2019

Available online 26 April 2019

Keywords:

Electrophoretic deposition

Reduced graphene oxide

Thin ﬁlms

Heat conduction

Smart windows

a b s t r a c t

Effective management of heat transfer, such as conduction and radiation, through glass windows is one

of the most challenging issues in smart window technology In this work, reduced Graphene Oxide (rGO) thinfilms of varying thicknesses are fabricated onto Fluorine-doped Tin Oxide (FTO) glass via electro-phoretic deposition technique The sample thicknesses increase with increasing number of deposition cycles (5, 10, 20 cycles) It is hypothesized that such rGO thinfilms, which are well-known for their high thermal conductivities, can conduct heat away laterally towards heat sinks and reduce near-infrared (NIR) transmittance through them, thus effectively slowing down the temperature increment indoors The performance of rGO/FTO in reducing indoor temperatures is investigated with a solar simulator and a UV-Vis-NIR spectrophotometer The 20-cycles rGO thinfilms showed 30% more NIR blocked at 1000 nm

as compared to clean FTO, as well as the least temperature increment of 0.57C following 30 min of solar irradiation Furthermore, the visible transmittance of the as-fabricated rGOfilms remain on par with commercial solarfilms, enabling up to 60% of visible light transmittance for optimal balance of trans-parency and heat reduction These results suggest that the rGO thinfilms have great potential in blocking heat transfer and are highly recommended for smart window applications

© 2019 The Authors Publishing services by Elsevier B.V on behalf of Vietnam National University, Hanoi This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

1 Introduction

Global warming and rapid fossil fuel depletion are major issues

that have continued to intensify over the years, yet remain without

a clear resolution Governments have been prompted to source for

renewable energy alternatives as well as methods to reduce their

energy consumption The building industry, in particular, consumes

a large percentage of energy each year, with room heating and

cooling making up at least 32% of a building's total energy

con-sumption [1,2] Modern building technology, in particular, is

typically assembled with many large scale window panels, thus causing the effect of heat and light transfer through windows to become increasingly signiﬁcant Therefore, smart window tech-nologies, which can modulate the transmittance of heat and light, are widely researched on due to their potential energy savings in lightings, heaters and air-conditioners Amongst smart window technologies, electrochromic devices, which are able to electrically modulate the transmittance of solar radiation, are one of the most widely investigated[3] However, heat can also be transferred in or out of the room through the glass window due to the conduction process, i.e by a temperature gradient The thermal conductivity of glass (with a typical thickness of 3 mm) is approximately 0.9 W/mK

[4] Depending on the temperature difference between the indoor and outdoor ambience, the direction of heat transfer will cause an increase or decrease in the indoor room temperature However, the management of heat conduction through the glass window has not been as widely investigated

* Corresponding author School of Materials Science and Engineering, Nanyang

Technological University, 50 Nanyang Avenue, Singapore 639798.

** Corresponding author School of Materials Science and Engineering, Nanyang

Technological University, 50 Nanyang Avenue, Singapore 639798.

E-mail addresses: tamnguyen@ntu.edu.sg (T.D Nguyen), miytok@ntu.edu.sg

(A.I.Y Tok).

Peer review under responsibility of Vietnam National University, Hanoi.

1 These authors contributed equally to this work.

Contents lists available atScienceDirect Journal of Science: Advanced Materials and Devices

j o u r n a l h o m e p a g e : w w w e l s e v i e r c o m / l o c a t e / j s a m d

https://doi.org/10.1016/j.jsamd.2019.04.002

Journal of Science: Advanced Materials and Devices 4 (2019) 252e259

Trang 2

An effective method for the management of heat conduction

can be achieved by coating a superior thermally-conductive layer

on the glass surface This layer, which works similarly to a double

or triple-glazed window, can minimize heat diffusion through the

glass[5,6] However, this approach can signiﬁcantly reduce the

weight and fabrication cost of the window pane The enhanced

in-plane thermal conductivities of such thin ﬁlms enable their

application in heat transfer management, in which the heat can be

conducted away and collected at the edge of the window panels

(Figure S1) Currently, carbon-based structures such as graphene,

reduced graphene oxide (rGO) and carbon nanotubes (CNT) have

been widely reported for their extremely high thermal

conduc-tivities Balandin et al reported a thermal conductivity as high as

4.84e5.30 kW/mK for a suspended single-layer graphene [7],

while Seol et al reported 600 W/mK in supported graphene[8]

Similarly, single-walled and multi-walled CNTs were reported to

have high thermal conductivities of 3500 W/mK between 300 and

800 K and 3000 W/mK at room temperature respectively[9] As

such, these carbon-based materials have huge potentials as

thermal interface materials for heat removal, cooling systems for

the electronic industry[10,11], anti-fogging devices and in

heat-able smart windows etc[12] This also gives rise to the possibility

of carbon-based windows in cool or warm climates which can

manage indoor temperatures by conducting heat inside or out

respectively Current commercial solarﬁlms (e.g., V-Kool,

Infra-tint, 3 M) can block UV radiation, reﬂect or absorb infrared (IR)

radiation and reduce glare with lower visible transmittance

However, theseﬁlms focus only on blocking wavelengths in the

solar spectrum but neglect the consideration of the warming

ef-fect of conducted heat Carbon-based smart windows, on the

other hand, allow management of both solar radiation and heat

conduction, and thus could provide insights into novel

applica-tions in theﬁeld of smart windows

Despite the high thermal conductivity of pristine graphene, its

cost of fabrication through techniques such as epitaxial growth,

chemical vapor deposition (CVD) and exfoliation is very high due to

limited yield or expensive substrates and is thus not an ideal

ma-terial when considering scale-up productions [13,14] Besides,

graphene and CNTs also possess low visible transparency and has

issues with homogenous, large-area surface grafting As such, rGO

is considered the next best alternative for fabricating window

coatings due to competitive thermal conductivities as high as

1043.5 W/mK[15] and 1390 W/mK [16] as previously reported

Furthermore, rGO also has the advantages of ease of fabrication,

mass producibility, strong infrared absorption and high

trans-parency[17]

In this study, rGOﬁlms of varying thicknesses were

electro-phoretically deposited onto FTO glass substrate and their effect on

blocking heat entry were analyzed with a solar simulator The

sample thicknesses increase with increasing number of deposition

cycles (5, 10, 20 cycles) It is hypothesized that

thermally-conductive rGO can conduct heat away and reduce heat transfer

through it, thus effectively slowing down the temperature

incre-ment indoors Electrophoretic deposition (EPD) was selected for its

potential to deposit homogenous coatings, control coating

thick-ness and low cost [18] As-fabricated rGO thin ﬁlms can be a

promising coating material to manage the heat conduction through

glass windows

2 Materials and experimental methods

The chemicals mentioned in this paper are obtained from

SigmaeAldrich unless otherwise stated Fluorine-doped tin oxide

(FTO) glass substrates are also obtained from Sigma Aldrich (Model:

TEC-7, Pilkington™)

2.1 Fabrication of graphene oxide via modified Hummer's method Graphene Oxide (GO) was obtained from pure graphiteflakes via modified Hummer's method[19,20] The fabrication procedure

is illustrated inFig 1 Graphite powder (1 g) was added into 98%

H2SO4 (40 ml) under continuous stirring Subsequently, KMnO4

(6 g) was gradually added into the mixture The oxidation of graphite to graphite oxide in this step is highly exothermic, thus small portions of KMnO4was added in 5e10 min interval Deion-ized (DI) water (50 ml) was slowly added to minimize heat gen-eration and the mixture was stirred for 2 h 30% H2O2(10 ml) was then added to the mixture and further stirred for 10 min to remove excess KMnO4 Next, the resultant mixture was centrifuged (Thermo Scientiﬁc Sorvall Legend X1R) at 8000 rpm for 10 min The residue was washed with 6% HCl and DI water before being centrifuged again The washing step was repeated for at least 4 times The residue was then mixed with DI water (200 ml) Lastly, the graphite oxide was exfoliated with a probe sonicator (SONICS Vibra-Cell) at 70% amplitude for 1 h to obtain a homogenous GO suspension

2.2 Reduction of GO via electrophoretic deposition The GO suspension was ﬁrst diluted to 1 mg/ml using Phosphate-buffered Saline (PBS) solution and subsequently, its pH was adjusted to 10 with NaOH The electrophoretic deposition (EPD) procedure of GO was carried out in a three-electrode set-up consisting of clean FTO as the working electrode, platinum sheet as the counter electrode and Ag/AgCl as the reference electrode (Figure S2)[21] Before EPD, N2gas was bubbled into the GO sus-pension under continuous stirring throughout the EPD procedure, starting from 30 min before the actual deposition A potential range

ofþ0.6 to 1.5 V was used to deposit reduced graphene oxide (rGO) onto the FTO substrate to obtain samples of 5, 10 and 20 cycles 2.3 Characterization

Surface morphology of the deposited rGO thin films was analyzed with a Field Emission Scanning Electron Microscope (FESEM, JEOL JSM-7600F) and Atomic Force Microscopy (AFM, Park Systems NX10) Thickness of thefilm samples were measured with the surface profiler (Alpha-Step IQ) X-ray Diffractometer (XRD, Panalytical X'Pert Pro), equipped with Cu-Karadiation, was carried out to analyze the crystallographic structure of the samples Fourier Transform Infrared Spectroscopy (FTIR, PerkinElmer Frontier) was carried out to observe the changes in molecular bonding following the reduction of GO The surface chemistry of as-fabricated rGO thinfilms was characterized by X-ray Photoelectron Spectrometer (XPS, Kratos AXIS Supra) The UV-Vis-NIR Spectroscopy (Agilent Cary 5000) was carried out to measure the visible light and NIR transmittance across the rGO/FTO samples

The performance of the different rGOﬁlms in blocking heat was analyzed with a solar simulator (Class 150 W XES-40S2-CE) equipped with a xenon lamp The set-up prepared for the solar simulation is depicted inFig 2 The set-up shown was enclosed in

an opaque acrylic box to prevent entry of external lighting With an irradiance of 1000 W/m2, the equipment simulates the sun, allowing the effect of rGO on blocking heat entry into the box to be analyzed Thermocouples were attached in the box to measure the increase in temperature in the internal environment during solar irradiation The samples were irradiated for 30 min and the internal temperature of the box was recorded at every minute The initial internal temperature of the box was maintained between 24.75 and 24.79C at the start of each analysis Irradiance of air and plain FTO glass substrate were also measured as references

L.P Yeo et al / Journal of Science: Advanced Materials and Devices 4 (2019) 252e259

Trang 3

3 Results and discussion

3.1 Morphology, crystal and chemical structures of

electrophoretically-deposited rGO thinﬁlms

Fig 3 a-c present the FESEM images of

electrophoretically-deposited rGOﬁlm (5, 10, 20-cycles) on FTO glass substrate The

formation of rGO thinﬁlms after the electrophoretic deposition

process can be clearly observed The deposited rGO ﬁlms are

relatively large, in the range of several micrometres They consist

of multiple, thin layers of overlapping rGO due to the

layer-by-layer alignment typical of EPD Irregular folds can be observed

on the ﬁlms which become more prominent as the number of

deposition cycles increases The thicknesses of the rGOfilms were also measured with a surface profiler and the average thickness is 0.374mm, 0.578mm and 1.759mm for 5, 10 and 20 cycles rGOfilms respectively The view of the rGO thinfilms with varying elec-trophoretically deposited cycles is included in Figure S3 The cyclic-voltammetry (CV) curves recorded during the electropho-retic deposition and reduction of GO are shown inFigure S4 A large reduction peak was recorded for 5-cycles reduction

at1.2 V, with a starting potential of e 0.85 V; 10-cycles reduction

at1.32 V, with a starting potential of 0.9 V; 20-cycles reduction

at1.06 V, with a starting potential of 0.4 V The large reduction peaks observed are due to the removal of oxygen functional groups in GO to form rGO[22]

Fig 1 Illustration of the GO fabrication procedure by modiﬁed Hummer's Method.

Fig 2 Illustration of the solar simulation experimental set-up.

ﬁlms deposited on FTO glass observed at 10 K magniﬁcation.

Trang 4

Fig 4a-c present the AFM images of rGO thinﬁlms of different

thicknesses The average surface roughness of 5, 10 and 20-cycles

rGO are estimated to be about 33.3, 39.8 and 58.3 nm,

respec-tively, as presented inFig 4d As expected, there is an increase in

theﬁlm surface roughness when an increasing amount of rGO was

deposited Despite the presence of folds observed in the FESEM

images, the surface roughness remains relatively low This suggests

that the current electrophoretic deposition and reduction method

is capable of producing relatively smoothﬁlms regardless of the

deposited thickness A study by Chen et al reported that cluttering

in the arrangement of graphene atoms could reduce the speed of

thermal phonon propagation and thus decrease the thermal

con-ductivity of graphene[23] As such, a smooth rGOﬁlm is highly

desirable for quick heat transfer across theﬁlm

Fig 5presents the FTIR spectra of rGO and drop-casted

gra-phene oxide (DC-GO)ﬁlms to conﬁrm the successful reduction of

GO to rGO with the electrophoretic deposition method The

pro-cedure for the fabrication of DC-GO is illustrated inFigure S4 From

the DC-GO spectra, it can be observed that GO was successfully

oxidized from graphite due to the presence of oxygen-containing

functional groups[24] The GO spectrum consists of a broad peak

centered at 3435 cm1which originates from the stretching mode

of OeH group, while the peak at 1642 cm1is associated with

ar-omatic C]C ring stretching, the broad peak at 1186-1458 cm1and

the peak at 1085 cm1is related to stretching of epoxy CeO groups

[25e27] Following reduction into rGO, it can be observed that peak

intensities associated with the alkoxy and hydroxyl groups are

signiﬁcantly reduced or have disappeared, suggesting successful

reduction of GO

Fig 6presents the XRD patterns of the rGOﬁlms As the ﬁlms

were deposited onto an FTO glass substrate, characteristic peaks of

FTO were observed at 2q¼ 26.6, 33.9, 37.9, 51.7, 61.8and 66.0

which corresponds to the (110), (101), (200), (211), (310) and (301) planes of SnO2(ICDD 01-070-4176), respectively The XRD pattern

of drop-cast graphene oxide (DC-GO) obtained from modiﬁed Hummer's method produced a peak at 2q¼ 9.3with an average

d-spacing of 0.95 nm, which corresponds to the (001) plane[28e30] Following reduction of GO, the GO peak disappears, indicating the successful removal of oxygen-containing functional groups Although there is an overlap in peaks, the diffraction peak char-acteristic of rGO is also located at 2q¼ 26.6in the rGOﬁlms, which

ﬁlms and (d) their corresponding surface roughness.

Fig 5 FTIR spectra of RGO and drop-casted graphene oxide (DC-GO) L.P Yeo et al / Journal of Science: Advanced Materials and Devices 4 (2019) 252e259

Trang 5

corresponds to the (002) plane [29] The d-spacing of rGO was

observed to be approximately 0.34 nm, with negligible differences

amongst the 5, 10 and 20-cycle samples

3.2 Surface chemistry and UV-Vis eNIR absorption of rGO thin

ﬁlms

Fig 7shows the XPS spectra of as-fabricated rGO thinﬁlms The

wide scan spectra (Fig 7a) of all samples indicate the presence of

C1s and O1s, which again conﬁrms the formation of rGO thin ﬁlms

The Sn3d peaks are present due to the FTO substrate, with the

Sn3d5/2and Sn3d3/2components located at approximately 487 and

496 eV, respectively There are small energy shifts observed as compared to typical SnO2XPS spectra (where Sn3d5/2and Sn3d3/2

components are located at 485 and 494 eV, respectively) due to fluorine doping in FTO glass substrate The fine XPS spectra of C1s (b), O1s (c) and Sn3d (d) of 5-cycles rGO thinfilm are presented in

Fig 7b-d By curve-fitting analysis (Gauss*Lorentz Algorithm), the C1s core-level spectrum of 5-cycles rGO thinfilms was deconvo-luted to obtain 3 main peaks: CeC (~284.4 eV), CeO (~285.8 eV), and C]O (~288 eV) The CeC peak is attributed to carbon with sp2 and sp3hybridization, with some shoulders at higher binding en-ergies due to the oxygen linkages (CeO, C]O) The O1s core-level spectrum was deconvoluted into three peaks: C]O (~531.1 eV), CeO (~533.7 eV), C(O)OH (~535.7 eV)[31] Thefine XPS spectra of

10 and 20-cycles rGO thinfilms are also presented inFigure S5 The detailed elemental composition of the various rGO thin films is presented inTable 1 In general, the atomic ratio of C/O is about 7:3 for all three rGO samples Interestingly, in the C1s deconvolution, while the CeC and CeO components remain unchanged, the C]O component mostly decreases with increasing number of deposition cycles For O1s deconvolution, the C]O component and carboxylic groups reduce while the CeO component increases with increasing number of deposition cycles This may imply the presence of less eCOOH and eCOH functional groups in the electrophoretically-deposited rGO thinfilms with increasing film thickness This is also in agreement with the observation from the FTIR and XRD analyses

Fig 8presents the UV-Vis-NIR spectra of the rGOﬁlms with different number of deposition cycles (5, 10, 20-cycles) within the range of 300e1600 nm[32] Wavelengths above 1600 nm were not included as the FTO glass substrate itself allows less than 30% infrared transmittance above 1600 nm [33] The effect of increasing rGO thickness on NIR transmittance thus cannot be observed clearly in that wavelength range and was subsequently

Fig 6 XRD patterns of rGO thin ﬁlms fabricated with different deposition cycles

(5-cycles, 10-(5-cycles, 20-cycles).

films The fine XPS spectra of C1s (b), O1s (c) and Sn3d (d) of 5-cycles rGO thin films.

Trang 6

omitted With an increasing thickness of rGOﬁlms deposited, the

transmittance of Vis and NIR wavelengths sees a general

decreasing trend The NIR transmittance of clean FTO, 5, 10 and

20-cycles rGO thin ﬁlms is in the range of 16.75e80.14%,

22.52e60.07% 16.47e45.19% respectively By increasing from 5 to

10 deposition cycles, there is approximately 12.63% more NIR

blocked at 1000 nm Increasing from 10 to 20 cycles shows

negligible difference in NIR blockage However, a 20-cycle rGO thin

ﬁlm still enables 30% more NIR blocked at 1000 nm as compared to

clean FTO In the visible range, there is a consistent reduction in

transmittance as the number of rGOﬁlm thickness increases The

visible transmittance decreases from 50.61 e 60.07% to

36.30e45.19% to 24.27e40.40% when the number of cycles

increased from 5 to 20 cycles In order for the rGO thinﬁlms to be

used in windows, the visible transparency has to be sufﬁciently

high Hence, these results suggest that there are limitations in

further increasing rGO deposition cycles to reduce the NIR blockage indefinitely Nonetheless, the visible transmittance of the as-fabricated rGO films remains on par with commercial solar films[34,35], enabling up to 60% of visible light transmittance for optimal balance of transparency and heat reduction

3.3 Reduction of heat transfer through glass using rGO thinﬁlms

Fig 9 presents the results from the solar simulation test As previously mentioned, the rGO samples (5, 10, 20-cycles) were irradiated with artiﬁcial light for a period of 30 min and the internal temperature of the box was recorded every minute Air and plain FTO glass substrate were also irradiated under the same parameters

as references As shown inFig 9a, following 30 min irradiation, the FTO samples coated with rGOfilms showed an increase in tem-perature of only 0.76C, 0.68C and 0.57C for 5, 10 and 20-cycles samples, respectively On the other hand, irradiating air and plain FTO glass substrates caused an increase by 4.40 C and 1.80C, respectively.Fig 9b shows the % increment in temperature with different samples A magnified graph of theDT of 5, 10, 20-cycles films is also included A steep decline in temperature increment can be observed once the rGO thinfilms were utilized The 5-cycles rGO thinfilms alone shows approximately 5.8 times and 2.4 times reduction in interior temperature increment as compared to air and FTO glass substrate, respectively The interior temperature incre-ment showed a 13% reduction when the rGO film thickness is increased from 5 to 10-cycles and a further 15.5% reduction when thefilm thickness increased from 10 to 20-cycles Increasing the film thickness show, as expected, lower increment in interior temperature There are 2 possible reasons for this explanation:

Firstly, according to the heat transfer equation - whereDQ/Dt is the rate of heat conduction,Кis the thermal conductivity of the material per unit thickness, A is the area of the material, L is the layer thickness andDT is the temperature difference across the material - increasingﬁlm thickness would result in a slower heat transfer through the rGOﬁlm by conduction, due to the presence

Fig 8 UV-Vis-NIR transmittance spectra of rGO ﬁlms (5-cycles, 10-cycles, 20-cycles)

over the wavelength range of 300e1600 nm.

Table 1

Elemental composition of rGO thin ﬁlms determined by XPS.

Sample Elemental composition (at.%) C1s deconvolution (at.%) O1s deconvolution (at.%)

Fig 9 The temperatureetime plots (a) and temperature change analysis (b) of the solar simulation results for different samples.

Trang 7

of more conduction pathways in the thicker ﬁlm Furthermore,

increasing thickness of the rGOﬁlm gives rise to denser ﬁlms with

better connectivity, thus increasing the ease of in-plane thermal

phonon propagation[36] Within the testing period, most of the

heat was likely conducted laterally across the rGO thinﬁlm instead

of through the sample, resulting in a postponement of

perpen-dicular heat entry Secondly, as previously observed in Fig 8,

increasing the rGOﬁlm thickness has the effect of reducing NIR

transmittance across the thinﬁlm The reduced entry of radiant

heat into the room also contributed to the lower room temperature

increment However, since there is a limit to how much NIR

transmittance can be blocked by increasing rGO thickness, this

suggests that the further reduction in interior temperature

incre-ment between the 10 and 20 cycle ﬁlm is likely due to the

preferred propagation of the thermal phonons through other

conduction pathways

4 Conclusion

In this study, the rGO thinﬁlms were investigated for its

po-tential to be incorporated into smart windows to block heat

transfer The GO suspension was fabricated via modiﬁed Hummer's

method and was reduced and deposited onto FTO substrates using

electrophoretic deposition technique Three different rGO thin

ﬁlms of varying number of deposition cycles (5, 10, 20-cycles) were

fabricated and tested in a UV-Vis-NIR spectrophotometer and a

solar simulator to determine their ability to block NIR wavelengths

and reduce indoor temperatures The 20-cycles rGO thin ﬁlms

showed an NIR transmittance of 18.8e40.4%, which is 30% more NIR

blocked at 1000 nm as compared to clean FTO It also showed the

least temperature increment of 0.57C following 30 min of solar

irradiation While maintaining excellent heat transfer reduction,

the visible transmittance of theﬁlms was also on par with

com-mercial solarﬁlms, enabling up to 60% of visible light transmittance

for optimal balance of transparency and heat reduction It is

sug-gested that the excellent heat blocking results of rGO thinﬁlms are

due to a combination of good heat conduction and reduced NIR

transmittance and as such, possesses great potential in

heat-blocking window technologies

Declaration of interest statement

The authors declare no conﬂict of interest

Acknowledgements

This research is supported by grants from the National Research

Foundation, Prime Minister's Ofﬁce, Singapore under its Campus

of Research Excellence and Technological Enterprise (CREATE)

Program

Appendix A Supplementary data

Supplementary data to this article can be found online at

https://doi.org/10.1016/j.jsamd.2019.04.002

References

[1] D Perera, N.-O Skeie, Comparison of space heating energy consumption of

residential buildings based on traditional and model-based techniques,

Buildings 7 (2) (2017) 27 https://doi.org/10.3390/buildings7020027

[2] D Ürge-Vorsatz, L.F Cabeza, S Serrano, C Barreneche, K Petrichenko, Heating

and cooling energy trends and drivers in buildings, Renew Sustain Energy

Rev 41 (2015) 85e98 https://doi.org/10.1016/j.rser.2014.08.039

[3] G.N Tiwari, Solar Energy: Fundamentals, Design, Modelling and Applications,

[4] M Rubin, Calculating heat transfer through windows, Int J Energy Res 6 (4) (1982) 341e349 https://doi.org/10.1002/er.4440060405

[5] B.P Jelle, Solar radiation glazing factors for window panes, glass structures and electrochromic windows in buildingsdmeasurement and calculation, Sol Energy Mater Sol Cell 116 (2013) 291e323 https://doi.org/10.1016/j.solmat 2013.04.032

[6] M Gr Vrachopoulos, M.K Koukou, G Filos, C Moraitis, Investigation of heat transfer in a triple-glazing type window at Greek climate conditions, Cent Eur J Eng 3 (4) (2013) 750e763 https://doi.org/10.2478/s13531-013-0130-9

[7] A.A Balandin, S Ghosh, W Bao, I Calizo, D Teweldebrhan, F Miao, C.N Lau, Superior thermal conductivity of single-layer graphene, Nano Lett 8 (3) (2008) 902e907 https://doi.org/10.1021/nl0731872

[8] J.H Seol, et al., Two-dimensional phonon transport in supported graphene, Science 328 (5975) (2010) 213 https://doi.org/10.1126/science.1184014 [9] E Pop, D Mann, Q Wang, K Goodson, H Dai, Thermal conductance of an individual single-wall carbon nanotube above room temperature, Nano Lett 6 (1) (2006) 96e100 https://doi.org/10.1021/nl052145f

[10] A.A Balandin, Thermal properties of graphene and nanostructured carbon materials, Nat Mater 10 (2011) 569 https://doi.org/10.1038/NMAT3064 [11] N Han, et al., Improved heat dissipation in gallium nitride light-emitting di-odes with embedded graphene oxide pattern, Nat Commun 4 (2013) 1452.

https://doi.org/10.1038/ncomms2448 [12] B.H Nguyen, V.H Nguyen, Promising applications of graphene and graphene-based nanostructures, Adv Nat Sci Nanosci Nanotechnol 7 (2) (2016),

023002 https://doi.org/10.1088/2043-6262/7/2/023002 [13] H Tan, D Wang, Y Guo, Thermal growth of graphene: a review, Coatings 8 (1) (2018) https://doi.org/10.3390/coatings8010040

[14] Md.S.A Bhuyan, Md.N Uddin, Md M Islam, F.A Bipasha, S.S Hossain, Syn-thesis of graphene, Int Nano Lett 6 (2) (2016) 65e83 https://doi.org/10.1007/ s40089-015-0176-1

[15] N.-J Song, C.-M Chen, C Lu, Z Liu, Q.-Q Kong, R Cai, Thermally reduced graphene oxide ﬁlms as ﬂexible lateral heat spreaders, J Mater Chem 2 (39) (2014) 16563e16568 https://doi.org/10.1039/c4ta02693d

[16] P Kumar, F Shahzad, S Yu, S.M Hong, Y.-H Kim, C.M Koo, Large-area reduced graphene oxide thin ﬁlm with excellent thermal conductivity and electromagnetic interference shielding effectiveness, Carbon 94 (2015) 494e500 https://doi.org/10.1016/j.carbon.2015.07.032

[17] S.J Rowley-Neale, E.P Randviir, A.S.A Dena, C.E Banks, An overview of recent applications of reduced graphene oxide as a basis of electroanalytical sensing platforms, Appl Mater Today 10 (2018) 218e226 https://doi.org/10.1016/j apmt.2017.11.010

[18] H Zhang, X Zhang, D Zhang, X Sun, H Lin, C Wang, Y Ma, One-step elec-trophoretic deposition of reduced graphene oxide and Ni(OH)2 composite ﬁlms for controlled syntheses supercapacitor electrodes, J Phys Chem B 117 (6) (2013) 1616e1627 https://doi.org/10.1021/jp305198j

[19] M Larisika, J Huang, A Tok, W Knoll, C Nowak, An improved synthesis route

to graphene for molecular sensor applications, Mater Chem Phys 136 (2) (2012) 304e308 https://doi.org/10.1016/j.matchemphys.2012.08.003 [20] J.T Han, B.J Kim, B.G Kim, J.S Kim, B.H Jeong, S.Y Jeong, H.J Jeong, J.H Cho, G.-W Lee, Enhanced electrical properties of reduced graphene oxide multi-layer ﬁlms by in-situ insertion of a TiO2 layer, ACS Nano 5 (11) (2011) 8884e8891 https://doi.org/10.1021/nn203054t

[21] S.J An, Y Zhu, S.H Lee, M.D Stoller, T Emilsson, S Park, A Velamakanni, J An, R.S Ruoff, Thin ﬁlm fabrication and simultaneous anodic reduction of deposited graphene oxide platelets by electrophoretic deposition, J Phys Chem Lett 1 (8) (2010) 1259e1263 https://doi.org/10.1021/jz100080c [22] H.-L Guo, X.-F Wang, Q.-Y Qian, F.-B Wang, X.-H Xia, A green approach to the synthesis of graphene nanosheets, ACS Nano 3 (9) (2009) 2653e2659.

https://doi.org/10.1021/nn900227d [23] L Chen, Y Zhang, Q Wu, Effect of graphene coating on the heat transfer performance of a composite anti-/deicing component, Coatings 7 (10) (2017).

https://doi.org/10.3390/coatings7100158 [24] T.F Emiru, D.W Ayele, Controlled synthesis, characterization and reduc-tion of graphene oxide: a convenient method for large scale producreduc-tion, Egypt J Basic Appl Sci 4 (1) (2017) 74e79 https://doi.org/10.1016/j.ejbas 2016.11.002

[25] N Sharma, V Sharma, Y Jain, M Kumari, R Gupta, S.K Sharma, K Sachdev, Synthesis and characterization of graphene oxide (GO) and reduced graphene oxide (rGO) for gas sensing application, Macromol Symp 376 (1) (2017)

1700006 https://doi.org/10.1002/masy.201700006 [26] V Loryuenyong, K Totepvimarn, P Eimburanapravat, W Boonchompoo,

A Buasri, Preparation and characterization of reduced graphene oxide sheets via water-based exfoliation and reduction methods, Adv Mater Sci Eng 2013 (2013) 5 https://doi.org/10.1155/2013/923403

[27] D Ickecan, R Zan, S Nezir, Eco-friendly synthesis and characterization of reduced graphene oxide, J Phys Conf Ser 902 (1) (2017), 012027 https://doi org/10.1088/1742-6596/902/1/012027

[28] Q Zhuo, J Gao, M Peng, L Bai, J Deng, Y Xia, Y Ma, J Zhong, X Sun, Large-scale synthesis of graphene by the reduction of graphene oxide at room temperature using metal nanoparticles as catalyst, Carbon 52 (2013) 559e564 https://doi.org/10.1016/j.carbon.2012.10.014

[29] M.J McAllister, et al., Single sheet functionalized graphene by oxidation and thermal expansion of graphite, Chem Mater 19 (18) (2007) 4396e4404.

https://doi.org/10.1021/cm0630800 L.P Yeo et al / Journal of Science: Advanced Materials and Devices 4 (2019) 252e259

Trang 8

[30] P Chen, H Li, S Song, X Weng, D He, Y Zhao, Adsorption of dodecylamine

hydrochloride on graphene oxide in water, Results Phys 7 (2017) 2281e2288.

https://doi.org/10.1016/j.rinp.2017.06.054

[31] S Drewniak, R Muzyka, A Stolarczyk, T Pustelny, M Kotyczka-Moranska,

M Setkiewicz, Studies of reduced graphene oxide and graphite oxide in the

aspect of their possible application in gas sensors, Sensors 16 (1) (2016).

https://doi.org/10.3390/s16010103

[32] T.D Nguyen, L.P Yeo, T.C Kei, D Mandler, S Magdassi, A.I.Y Tok, Efﬁcient

near infrared modulation with high visible transparency using SnO2eWO3

nanostructure for advanced smart windows, Adv Opt Mater 0 (0) (2019)

1801389 https://doi.org/10.1002/adom.201801389

[33] H Ling, L.P Yeo, Z Wang, X Li, D Mandler, S Magdassi, A.I.Y Tok, TiO 2 eWO 3

coreeshell inverse opal structure with enhanced electrochromic performance

in NIR region, J Mater Chem C 6 (31) (2018) 8488e8494 https://doi.org/10 1039/c8tc01954a

[34] 3M 3M™ Sun Control Window Films, Prestige Series for Residential, 2019.

https://www.3m.com.sg/3M/en_SG/company-sg/all-3m-products/~/3M-Sun-Control-Window-Films-Prestige-Series-for-Commercial/?

N¼5002385þ3292716662&preselect¼3293786499&rt¼rud [35] Eastman Chemical Company, iQUE TM BY V-KOOL Architecture Window Films,

2018 https://www.v-kool.com/architecture-window-ﬁlm [36] G Lian, C.-C Tuan, L Li, S Jiao, Q Wang, K.-S Moon, D Cui, C.-P Wong, Vertically aligned and interconnected graphene networks for high thermal conductivity of epoxy composites with ultralow loading, Chem Mater 28 (17) (2016) 6096e6104 https://doi.org/10.1021/acs.chemmater.6b01595 L.P Yeo et al / Journal of Science: Advanced Materials and Devices 4 (2019) 252e259

Định dạng
Số trang	8
Dung lượng	1,73 MB