Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

Polymer based nanocomposites are gaining attention in various fields of science and technology due to its tunable properties. In this work, we report for the first time, the preparation and study on electrical and mechanical properties of standalone poly(vinyl alcohol) (PVA) based graphite nanoplatelet (GnP) composite films using modified film casting technique. Our modified tape casting method can produce films with uniform thickness, and uniform dispersion of filler deprived of pinholes. This technique is scalable for the mass production of polymer composite films for device application. We have obtained a significant enhancement in the electrical conductivity of 9 orders of magnitude and a maximum value of 0.143 S/m using PVA–GnP composites. To the best of our knowledge, this increase is the highest among the reported values for PVA–GnP composite films. However, a reduction in crystallinity and tensile strength can be seen with the addition of GnP fillers. The maximum tensile strength obtained for PVA–GnP composite films was 15 MPa and is adequate for use in electronic applications and devices. The effect of filler addition in PVA is discussed in detail. © 2020 Wiley Periodicals LLC

World University root node

Department of Physics

School of Advanced Sciences

Vellore Campus

Department of Manufacturing Engineering

School of Mechanical Engineering

Journal of Applied Polymer Science

Enhanced electrical conductivity and structural, mechanical characterization of standalone poly(vinyl alcohol)-graphite nanoplatelets composite films

High-energy ball milling is a promising and effective technique for the production of aluminium nanoparticles. Elemental aluminium powder of 325 mesh, 99.5% purity is taken for this investigation. A planetary ball mill, PM 100, with tungsten carbide balls of diameter 9.5 mm was used. The vial containing 62 g of powder and 620 g of tungsten carbide balls in the ratio 1:10 (wt/wt) was utilized. Toluene was used as a wet grinding media in order to reduce the heat produced during ball milling operation. Ball milling was carried out for 70 hours and the obtained nano-particles were characterized using wide angle X-Ray diffraction technique. The peaks were analyzed by using PANalytic X'pert HighScore software. Optimum milling time for producing nanoparticles of size 20-21 nm was found to be 50-60 hours. © 2018 IAEME Publication.

International Journal of Mechanical Engineering and Technology

Effect of milling time on production of aluminium nanoparticle by high energy ball milling

Expanded graphite (EG) and multiwalled carbon nanotubes (MWNTs) based hybrid nano-composites were prepared with polyamide 6 (PA6) matrix via melt-mixing technique using a conical twin-screw micro-compounder. A novel organic modifier (lithium salt of 6-aminohexanoic acid; Li-AHA) was employed to modify MWNTs, which was utilized to intercalate Li-AHA modified MWNTs into the partially exfoliated EG gallery. Morphological investigation showed the intercalation of Li-AHA modified MWNTs into a partially exfoliated EG gallery in an EG/MWNTs-m2h hybrid, whereas the unmodified EG/MWNTs-h hybrid mixture exhibited a separate identity in the mixture. Improved interaction via melt-interfacial reaction between the acid end group of PA6 and the amine functionality of Li-AHA in the EG/MWNTs-m2h hybrid filler was confirmed by Fourier transform infrared spectroscopic analysis. The extent of melt-interfacial reaction was increased as a function of Li-AHA concentration in the filler. Wide angle X-ray diffraction analysis showed the existence of the α-crystalline phase of PA6. The incorporation of MWNTs, EG and EG/MWNTs hybrid in the PA6 matrix has favoured an α-crystalline structure of the PA6 phase. Crystallization studies have indicated a significant increase in the bulk crystallization temperature of the PA6 phase in the presence of MWNTs, EG and the EG/MWNTs hybrid filler. Moreover, the formation of PA6 'trans-crystalline lamellae' on the MWNTs surface was facilitated in the case of composites with MWNTs and the EG/MWNTs hybrid filler. An attempt has been made to investigate the role of the EG/MWNTs hybrid filler in influencing the crystallization behaviour of the PA6 phase in the hybrid nano-composites. © 2015 the Owner Societies.

Physical Chemistry Chemical Physics

Influence of hybrid nano-filler on the crystallization behaviour and interfacial interaction in polyamide 6 based hybrid nano-composites

Particle-filled polymer composites are becoming attractive because of their wide applications and low cost. In this study, the effects of fillers such as mica and fly ash, at varying concentrations, on the mechanical, thermal, electrical, rheological, and morphological properties of polyester thermoplastic elastomer (Hytrel®) were investigated. Composites of Hytrel ® with varying concentrations (5-40 wt%) of mica and fly ash were prepared by twin screw extrusion. Mechanical properties, such as flexural strength and modulus, were found to increase with filler concentration. Mica showed a moderate increase in tensile strength with low concentrations, whereas the strength decreased with fly ash concentration. Thermal and electrical properties of the composites were found to increase with filler concentration. Morphological studies revealed that there was a good dispersion of filler in the polymer matrix at lower concentrations. © The Author(s), 2010.