Nanomaterials have been actively pursued for biological and medical applications in recent years. Here, we report the synthesis of several new poly(ethylene glycol) grafted branched polymers for functionalization of various nanomaterials including carbon nanotubes, gold nanoparticles (NPs), and gold nanorods (NRs), affording high aqueous solubility and stability for these materials. We synthesize different surfactant polymers based upon poly(γ-glutamic acid) (γPGA) and poly(maleic anhydride-alt-1-octadecene) (PMHC18). We use the abundant free carboxylic acid groups of γPGA for attaching lipophilic species such as pyrene or phospholipid, which bind to nanomaterials via robust physisorption. Additionally, the remaining carboxylic acids on γPGA or the amine-reactive anhydrides of PMHC18 are then PEGylated, providing extended hydrophilic groups, affording polymeric amphiphiles. We show that single-walled carbon nanotubes (SWNTs), Au NPs, and NRs functionalized by the polymers exhibit high stability in aqueous solutions at different pH values, at elevated temperatures, and in serum. Morever, the polymer-coated SWNTs exhibit remarkably long blood circulation (t1/2 = 22.1 h) upon intravenous injection into mice, far exceeding the previous record of 5.4 h. The ultralong blood circulation time suggests greatly delayed clearance of nanomaterials by the reticuloendothelial system (RES) of mice, a highly desired property for in vivo applications of nanomaterials, including imaging and drug delivery.

Biodiesel is considered as an alternative fuel which can replace the traditional fuels easily with its less hazardous effects and economical pricing. This study compares an ultrasonic‐assisted catalytic transesterification using ZnO nanocatalyst for waste cooking oil (WCO) with the conventional stirring method. The structural and morphological characterizations of prepared catalysts were done by XRD and FESEM with EDX methods. The effect of reaction parameters such as oil to methanol ratio, catalyst amount and reaction time was investigated to optimize the transesterification conditions. GC/MS and FTIR analysis have been carried out to identify and confirm the presence of fatty acid methyl esters (FAME) under optimum conditions. The FAME conversion yield up to 96% under ultrasonication method was calculated. Two important fuel properties like density and viscosity were analyzed and compared with the standard biodiesel. These studies provided the clear evidence that WCO can be employed as a substantial source of biodiesel as fuel in diesel engines. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1176–1182, 2018

This work demonstrates the fabrication of a composite nanomaterial consisting of spherical silica nanoparticles decorated onto the graphene sheets which has been prepared by the sonication-assisted method. Graphene/silica nanocomposites were fabricated by the hydrolysis of tetraethyl orthosilicate in the presence of graphene oxide which has been obtained by modified Hummer's method. The obtained nanostructures were characterised by the X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD analysis depicts the coexistence of silica and graphene in the composite material. The morphology of synthesised silica-graphene nanocomposites was characterised by SEM and TEM. All images have been observed in the presence of SiO 2 nanoparticles of similar sizes which were grafted on the surface of graphene effectively. More significantly, the BET analysis revealed that the silica decorated graphene nanocomposites exhibit enhanced surface area than bare silica and graphene.