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Rubber nanocomposites are being studied because of their unique characteristics. Fillers are used in rubbers and elastomers to increase certain qualities for their ultimate uses. Fillers are used to strengthen rubber such as graphene/graphene oxide for the majority of activities. The hardness, modulus, anti-ageing and gas barrier properties of nanofilled-reinforced rubber are greater than pristine rubber. Studies from the literature depicted 150% increment in elastic modulus, 27.6% increment in modulus of rigidity and 35% increment in hardness of nitrile butadiene rubber when reinforced with graphene oxide (GO). Bulk, shear and Young's modulus of vulcanised rubber rises by 19.13%, 21.11% and 26.89% when infused with carbon nanotube. Because of its unique electrical, thermal and mechanical characteristics, rubber nanocomposites loaded with GO are also in high demand in industrial applications. Rubber nanocomposites, different nanofillers like graphene and graphene oxide and their benefits have been discussed. The review also outlines the rubber/GO nanocomposites' production procedures, novel characteristics and possible uses. [ABSTRACT FROM AUTHOR]

Heat dissipation is very essential for the efficient working of electronic devices. There is a widespread demand for high thermal conductivity materials. Boron nitride nanotubes have high thermal conductivity but due to their poor interfacial adhesion with polymers, their use as heat dissipating material is restricted. In this study, a silane-coupling agent has been used to modify the boron nitride nanotubes. These tubes were then inserted in polymethyl methacrylate matrix. Various properties such as thermal conductivity, storage modulus, and loss factor have been predicted. Molecular dynamics simulations have also been used for accurate prediction of the properties of boron nitride nanotubes/polymethyl methacrylate composites. The boron nitride nanotubes weight percentage was varied from 0% to 70% for studying the effect on thermal conductivity, storage modulus, and loss factor. The experimentally obtained thermal conductivity increased rapidly from 0.6 W/mK at 40 wt.% of boron nitride nanotubes to about 3.8 W/mK at 80 wt.% of boron nitride nanotubes in polymethyl methacrylate matrix (an increase of nearly 533%). A similar trend was obtained using molecular dynamics simulations. The storage modulus increased from 2 GPa (for pure polymethyl methacrylate) to about 5 GPa (for 70 wt.% boron nitride nanotubes). The glass transition temperature of boron nitride nanotubes/polymethyl methacrylate composites shifted to higher temperatures with an increase in boron nitride nanotubes weight percentage. [ABSTRACT FROM AUTHOR]

A computational method based on molecular dynamics simulation has been used to investigate the tribological behavior of carbon nanotube reinforced styrene-butadiene rubber. A three-layer molecular model in which top and bottom layers with Fe atoms and core with styrene-butadiene rubber matrices have been designed. The effect of sliding velocities from 1 m/s to 11 m/s has been studied at an applied normal loading. The properties predicted are abrasion rate and coefficient of friction. The average values of coefficient of friction and abrasion rate decrease from 0.451 to 0.328 and 21.16 to 16.5%, respectively, under sliding velocities of 1 m/s to 11 m/s. The molecular dynamics results show the decrease in coefficient of friction and abrasion rates with increasing sliding velocity. [ABSTRACT FROM AUTHOR]

Single layer graphene sheets and carbon nanotubes have resulted in the development of new materials for a variety of applications. Though there are a large number of experimental and numerical studies related to these nanofillers, still there is a lack of understanding of the effect of geometrical characteristics of these nanofillers on their mechanical properties. In this study, molecular dynamics simulation has been used to assess this issue. Two different computational models, single layer graphene sheets–copper and carbon nanotube–copper composites have been examined to study the effect of nanofiller geometry on Young’s modulus and thermal conductivity of these nanocomposites. Effect of increase in temperature on Young’s modulus has also been predicted using molecular dynamics. The effect of nanofiller volume fraction (Vf) on Young’s modulus and thermal conductivity has also been studied. Results of thermal conductivity obtained using molecular dynamics have been compared with theoretical models. Results show that with increase in Vf the Young’s modulus as well as thermal conductivity of single layer graphene sheets–Cu composites increases at a faster rate than that for carbon nanotube–Cu composite. For the same Vf, the Young’s modulus of single layer graphene sheets–Cu composite is higher than carbon nanotube–Cu composite. [ABSTRACT FROM AUTHOR]

The present study focuses on modeling of carbon nanofibers (CNFs) and evaluating the effect of their reinforcement in polypropylene (PP) matrix. A novel approach for modeling of CNF has been explained in this study. Molecular dynamics (MD) simulation has been used to study the effect of CNF volume fraction (Vf) and aspect ratio (l/d) on mechanical properties of CNF–PP composites. Materials Studio 5.5 has been used as a tool for finding the modulus and damping in composites. CNF composition in PP was varied by volume from 0 to 16%. Aspect ratio of CNF was varied from l/d = 5 to l/d = 100. Results have also been obtained for longitudinal loss factor (η11). To the best of the knowledge of the authors, till date there is no study, either experimental or analytical, which predicts η11 for CNF–PP composites at nanoscale. Hence, this will be a valuable addition in the area of nanocomposites. Results show that with only 2% addition by volume of CNF in PP, E11 increases by 748%. Thereafter, the increase is at a lower rate. Increase in E22 is very less in comparison to the increase in E11. With increase in CNF aspect ratio (l/d) till l/d = 60, the longitudinal loss factor (η11) decreases rapidly. Thereafter, the decrease is smaller. Results of this study are in agreement with those predicted by Shinichi et al. [ABSTRACT FROM AUTHOR]

Blunt bowel and mesenteric injuries (BBMI) are frequently missed despite the widespread use of computed tomography (CT). Early diagnosis for timely management of surgically significant blunt bowel and mesenteric injuries (sBBMI) can be challenging. Several tools predictive for sBBMI have been proposed such as the “Bowel Injury Prediction Score” (BIPS) that is based on presence of abdominal tenderness, white blood cell count ≥17,000/mm3 and CT grade. The utility of this scoring system for early diagnosis of sBBMI has neither been studied in an Indian population nor prospectively validated.A single-centre prospective cohort study was conducted at a Trauma Centre in India. After screening of 1793 patients with blunt trauma abdomen who presented between 1st January 2022 and 31st August 2022 and underwent CT scan, eventually, 80 patients of age >18 years, hemodynamically stable and CT finding suspicious of BBMI were included. BIPS score was calculated. Patients were followed to evaluate the outcome.The incidence of sBBMI was 3.06%. Mean age of study patients was 36.2 ± 16.5 years with male predominance (92.5%) and road traffic accidents the commonest mode of injury. Patients with BBMI were more likely to require operative intervention in the presence of abdominal tenderness at presentation (p < 0.01) and CT grade ≥4 (p < 0.01). For patients with WBC counts of ≥17,000/mm3, no statistically significant difference was noted in the need for operative intervention. BIPS ≥2 had 94.5% sensitivity, 72% specificity, 88% PPV, and 86% NPV for identifying patients with sBBMI.Calculation of BIPS at the time of presentation can avoid unnecessary delays in surgical management and thereby reduce overall morbidity and mortality even in an Indian setup. However, WBC counts > 17,000/mm3 were not found to be predictive of sBBMI. [ABSTRACT FROM AUTHOR]