This paper describes a green method for the synthesis of graphenic material from cane sugar, a common disaccharide. A suitable methodology was introduced to immobilize this material on sand without the need of any binder, resulting in a composite, referred to as graphene sand composite (GSC). Raman spectroscopy confirmed that the material is indeed graphenic in nature, having G and D bands at 1597 and 1338 cm(-1), respectively. It effectively removes contaminants from water. Here, we use rhodamine 6G (R6G) as a model dye and chloropyrifos (CP) as a model pesticide to demonstrate this application. The spectroscopic and microscopic analyses coupled with adsorption experiments revealed that physical adsorption plays a dominant role in the adsorption process. Isotherm data in batch experiments show an adsorption capacity of 55 mg/g for R6G and 48 mg/g for CP, which are superior to that of activated carbon. The adsorbent can be easily regenerated using a suitable eluent. This quick and cost-effective technique for the into a commercial water filter with appropriate engineering.

Towards a mesoscopic model of water-like fluids with hydrodynamic interactions J. Chem. Phys. 135, 124902 (2011) A semiclassical study of the thermal conductivity of low temperature liquids J. Chem. Phys. 135, 114105 (2011) Rheological properties of alumina nanofluids and their implication to the heat transfer enhancement mechanism J. Appl. Phys. 110, 034316 (2011) Reverse nonequilibrium molecular dynamics simulation of thermal conductivity in nanoconfined polyamide-6,6 J. Chem. Phys. 135, 064703 (2011) Heat transport in polymer-dispersed liquid crystals under electric field This paper envisages a mechanism of heat conduction behind the thermal conductivity enhancement observed in graphene nanofluids. Graphene nanofluids have been prepared, characterized, and their thermal conductivity was measured using the transient hot wire method. The enhancements in thermal conductivity are substantial even at lower concentrations and are not predicted by the classical Maxwell model. The enhancement also shows strong temperature dependence which is unlike its carbon predecessors, carbon nanotube (CNT) and graphene oxide nanofluids. It is also seen that the magnitude of enhancement is in-between CNT and metallic/metal oxide nanofluids. This could be an indication that the mechanism of heat conduction is a combination of percolation in CNT and Brownian motion and micro convection effects in metallic/metal oxide nanofluids, leading to a strong proposition of a hybrid model.

Arsenic-free drinking water, independent of electrical power and piped water supply, is possible only through advanced and affordable materials with large uptake capacities. Confined metastable 2-line ferrihydrite, stable at ambient temperature, shows continuous arsenic uptake in the presence of other complex species in natural drinking water and an affordable water-purification device is made using the same.

This paper explores the reduction of water dispersed graphene oxide (GO) by sunlight as an environmentally friendly alternative to conventional methods of reduction of GO. The possible mechanism of the reduction process is delineated. The electrical and thermal conductivity, the degree of reduction and structural defects of sunlight reduced GO (sRGO) are studied thoroughly and compared with RGO samples produced through hydrazine (hRGO) and hydrothermal (hyRGO) reduction routes. The study reveals that the production of sRGO is feasible and its electronic properties are on a par with those of hRGO. Interestingly, sRGO showed the least structural defects, good dispersibility and higher conductivity vis-avis its counterparts. This cost effective and environmentally friendly method of reducing GO to RGO with enhanced electronic properties may find applications in bio-sensing and electrochemical energy storage devices.

Cyclodextrin–polymer composite electrospun nanofibers were developed for micropollutant (MP) removal from water. The fibers were fabricated by electrospinning of mixed poly­(ether sulfone) (PES) and β-cyclodextrin (CD) solutions under optimal conditions. The composite fibers were compared with bare PES nanofibers prepared by the same method. Scanning electron microscopy revealed that CD did not alter the fiber morphology, while the fiber capacity for MP uptake was enhanced by CD through the formation of inclusion complexes. The availability of CD on the fibers was confirmed by the emergence of visible luminescence due to the inclusion of a quantum cluster, Au25SBB18 (SBB = 4-(tert-butyl)­benzylmercaptan in thiolate form), in the cavities of CD exposed on fiber surfaces. The steroid hormone estradiol (E2) (100 ng/L) and pesticide chlorpyrifos (CP) (5 mg/L) were used as model pollutants in batch experiments designed to measure uptake potential. The nanofibers interact strongly with the model pollutants because of their high surface area and surface affinity. Increases of 20% in E2 uptake and 80% in CP uptake compared with bare PES nanofibers were observed. This behavior indicates promising applications of CD-containing materials for MP removal in water treatment and membrane technology.