Arun Kumar Yadav

Graphene and hexagonal boron nitride filled epoxy nanocomposites.

This project will be carried out in two stages, first is to establish the high concentration dispersion of hexagonal boron nitride and graphene using the suitable surfactant.

And second is to use this high concentration dispersion of hexagonal boron nitride for the preparation of epoxy nanocomposites.

The hexagonal boron nitride dispersion and its nanocomposites will be characterized using various characterization techniques such as UV-Vis-NIR spectroscopy, FTIR spectroscopy, tensile testing, SEM and TEM studies.

To develop the graphene and boron nitride filled polymer nanocomposites with higher thermal conductivity for electronic packaging applications.

Objectives

Introduction And basics.

Literature review.

Experimental work.

Results and Discussion.

Conclusion.

References.

CONTENTS

Hexagonal boron nitride is emerged as superior reinforcing filler for thermal management applications.

Simililary, graphene also exhibit the highest thermal conductivity measured so far.

The challenge is that overcome the aggregate formation of hexagonal boron nitride and graphene in the polymer matrix due to the strong Vander waals forces of attraction between the hexagonal boron nitride sheets and graphene.

In this regard, surfactant assisted dispersion strategy will be adopted to overcome the problem of aggregation of hexagonal boron nitride as well as graphene in epoxy nanocomposites.

INTRODUCTION

BASICCOMPOSITE MATERIALS-

Composite material is a material composed of two or more distinct phases (matrix phase and dispersed phase (filler)) and having bulk properties significantly different form those of any of the constituents.

Matrix phase

The primary phase, having a continuous character, is called matrix. Matrix is usually more ductile and less hard phase.

The functions and requirements of the matrix are to: Keep the fibers in place in the structure; Help to distribute or transfer loads; Protect the filaments, both in the structure and before and during fabrication; Control the electrical and chemical properties of the composite; Carry interlaminar shear.

Dispersed (reinforcing) phaseThe second phase (or phases) is embedded in the matrix in a discontinuous form.

This secondary phase is called dispersed phase. Dispersed phase is usually stronger than the matrix, therefore it is sometimes called reinforcing phase.

The needs or desired properties of the matrix that depend on the purpose of the structureare:

Minimize moisture absorption and have low shrinkage; Low coefficient of thermal expansion; Must flow to penetrate the fiber bundles completely and eliminate voids during the

compacting/curing process; have reasonable strength, modulus and elongation (elongation should be greater than fiber);

Must be elastic to transfer load to fibers; Have strength at elevated temperature (depending on application); Have low temperature capability (depending on application); Have excellent chemical resistance (depending on application); Be easily processable into the final composite shape; Have dimensional stability (maintain its shape).

BASIC

LITERATURE REVIEW

(a) Thermal conductivity of the neat epoxy and epoxy composites as a function of test temperature

(b) Thermal conductivity and thermal conductivity enhancement of the neat epoxy and its composites at 100 C.

J. Yu et al. / Polymer 53 (2012) 471e480

Boron nitride nanoplatelets for epoxy composites with improved thermal properties

(a) TEM images of h-BN naonsheets, (b) single/few layer h-BN nanosheets and (c) thick h-BN sheets. All the scale bars are 100 nm.

Thermal enhancement factors of h-BN nanosheet based composites andh-BN control based nanocomposites

Z. Lin et al. / Composites Science and Technology 90 (2014) 123–128

Exfoliated hexagonal boron nitride-based polymer nanocomposite

with enhanced thermal conductivity for electronic encapsulation

Boron nitride-MWCNT/epoxy hybrid nanocomposites: Preparation and mechanical properties

Scanning electron microscope images of BN nanoplatelets. High resolution TEM images of BN

nanoplatelets

H. Ulus et al. / Applied Surface Science xxx (2014) xxx– xxx

H. Ulus et al. / Applied Surface Science xxx (2014) xxx– xxx

Boron nitride-MWCNT/epoxy hybrid nanocomposites: Preparationand mechanical properties

Preparation process of the epoxy composites.

Elasticity Modulus charts of epoxy nanocomposites with different nanopar-ticle loadings.

10 mg of graphene + 10 mg of exfoliated boron nitride mixed in different PVP solution.

This solution ultrasonicated for 15 minutes then solution is tested in UV-Vis-NIR (ultra-violet (uv), visible (vis) and near infra-red (nir) radiation).

Spectra of exfoliated graphene and hexagonal boron nitride caputured in graph shown next bellow.

Experimental

200 400 600 800

0.2

0.3

0.4

0.5

0.6

Ab

so

ran

ce (

a.u

.)

Wavelength (nm)

Figure 1: UV-Vis-NIR spectra of exfoliated graphene and hexagonal boron nitride

Results and discussion10 mg graphene + 10 mg of hexagonal boron nitride and PVP solution has been prepared. This solution ultrasonicated for 15 minutes then solution is tested in UV-Vis-NIR. Spectra of exfoliated graphene and hexagonal boron nitride caputured in graph shown above. In the graph 1st top peak point shows present of boron nitride and 2nd peak point shows the presence of graphene oxide. As wavelength increases absorption decreases.

0.00 0.25 0.50 0.75 1.000.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

PVA concentration (wt%)

Ab

so

rpti

on

(a

.u.)

Figure 2: UV-Vis-NIR spectra of PVA assisted dispersion of graphene and exfoliate boron nitride

Result and discussion

ConclusionThe hexagonal boron nitride dispersion and its nanocomposites will be

characterized using various characterization techniques such as UV-Vis-

NIR spectroscopy, FTIR spectroscopy, tensile testing, SEM and TEM

studies that shows higher bulk properties .

The graphene and boron nitride filled polymer nanocomposites shows

higher thermal conductivity and higher strength for electronic packaging

applications.

resulting in the significant improvement of dynamic mechanical,

dielectric and thermal properties.

These results are beneficial to make the composites own great potential

applications, especially for electronics and aerospace industries.

References

1. Ziyin Lin a,b, Andrew Mcnamara c, Yan Liu b, Kyoung-sik Moon b, Ching-Ping Wonga,d,-Composites Science and Technology 90 (2014) 123–128

2. Jinhong Yu, Xingyi Huang*, Chao Wu, Xinfeng Wu, Genlin Wang, Pingkai Jiang*-Polymer 53 (2012) 471e480

3. H. Liem, H.S. Choy -Solid StateCommunications163(2013)41–45.

4. L. Ci,L.Song,C.Jin,D.Jariwala,D.Wu,Y.Li,A.Srivastava,Z.F.Wang,K.Storr, L. Balicas,F.Liu,P.M.Ajayan,Nat.Mater.9(2010)430.

5. M.P.Levendorf,C.J.Kim,L.Brown,P.Y.Huang,R.W.Havener,D.A.Muller,J. Park,Nature488(2012)627.

6. K.C. Yung,H.M.Liem,J.Appl.Polym.Sci.106(2007)3587. 7. I. Calizo,W.Bao,F.Miao,C.N.Lau,A.A.Balandin,Appl.Phys.Lett.91(2007) 201904.