The surface chemical modification of cellulosic fibres in view of their use in composite materials

The surface modification of various cellulosic materials was studied in heterogeneous conditions using different grafting agents bearing anhydride or isocyanate reactive groups. Some of these reagents were oligomeric, others polymeric and most were chosen so as to provide a non-polar character to the surface of the fibres in view of their possible use as reinforcing agents in composites based on polymeric matrices. The success of these chemical modifications was assessed by Fourier-transform Infrared Spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and elemental analysis. The accessibility of the superficial OH groups varied as a function of the coupling agent in terms of both molecular size and chemical nature and ranged between 1 and 3% of the total hydroxy groups borne by the initial cellulose sample. This revised version was published online in August 2006 with corrections to the Cover Date.     

聚醚硅油对聚苯乙烯表面极性的改性

聚醚硅油对聚苯乙烯表面极性的改性;变角衰减全反射傅立叶变换红外光谱;接触角;表面极性;聚醚硅油;表面能     

Recent advances in the use of graphene-family nanoadsorbents for removal of toxic pollutants from wastewater

Adsorption technology is widely considered as the most promising and robust method of purifying water at low cost and with high-efficiency. Carbon-based materials have been extensively explored for adsorption applications because of their good chemical stability, structural diversity, low density, and suitability for large scale production. Graphene – a single atomic layer of graphite – is the newest member in the family of carbon allotropes and has emerged as the “celeb” material of the 21st century. Since its discovery in 2004 by Novoselov, Geim and co-workers, graphene has attracted increased attention in a wide range of applications due to its unprecedented electrical, mechanical, thermal, optical and transport properties. Graphene's infinitely high surface-to-volume ratio has resulted in a large number of investigations to study its application as a potential adsorbent for water purification. More recently, other graphene related materials such as graphene oxide, reduced graphene oxide, and few-layered graphene oxide sheets, as well as nanocomposites of graphene materials have also emerged as a promising group of adsorbent for the removal of various environmental pollutants from waste effluents. In this review article, we present a synthesis of the current knowledge available on this broad and versatile family of graphene nanomaterials for removal of dyes, potentially toxic elements, phenolic compounds and other organic chemicals from aquatic systems. The challenges involved in the development of these novel nanoadsorbents for decontamination of wastewaters have also been examined to help identify future directions for this emerging field to continue to grow.