2008 DEC 29 - (VerticalNews.com) -- "Nanofiltration (NF) is considered to be an intermediate process between ultrafiltration (UF) and reverse osmosis (RO). In the present work, chitosan derivative containing carboxylic acid group (-COOH), i.e," scientists in Surat, India report.

  "N,O-carboxymethyl chitosal (NOCC), is prepared. Then, the NOCC composite NF membrane having a polyether sulfone (PES) UF membrane as the substrate is prepared using a method of coating and crosslinking, in which glutaraldehyde solution is used as the crosslinking agent. The developed membranes are characterized in terms of Fourier transform infrared/attenuated total reflectance (FTIR/ATR), scanning electron microscopy/energy dispersive V ray analysis (SEM/EDXA), elemental analysis (EA), swelling behavior, tensile strength, and thermogravimetric analysis (TGA), which confirm the formation of the target membranes. Rejection efficiency of nickel ions from aqueous Solutions, of nickel sulfate and nickel chloride, is investigated. The experiments are carried Out for different feed concentrations, feed flow rates and applied pressures and the corresponding permeate flux and rejections are measured. The maximum observed rejection is found to be 80 and 62% of 5 ppm, 78 and 59%, of 10 ppm; and 74 and 57% of 50 ppm feed concentration of nickel sulfate-water and nickel chloride-water systems, respectively," wrote A.G. Boricha and colleagues ...read more

  2008 DEC 29 - (VerticalNews.com) -- According to recent research from South Korea, "A series of waterborne polyurethane (WBPU)/clay nanocomposite coating materials were prepared by prepolymer process with different clay contents (0-2 wt %). The study investigated surface structure as well as water resistance, thermal, mechanical, and water vapor permeability (WVP) of composite materials as a function of clay contents."

  "The glass transition temperature of composite materials was higher than pristine WBPU and also increased with increasing clay contents. Thermal stability, and water resistance of the nanocomposite films also increased, when compared with pristine WBPU, and these properties increased with an increase in clay content. The maximum tensile strength was found with optimum clay content (1 wt %) of composite films. The WVP of coated nylon fabrics depend on the clay content and temperatures. The rate (%) of WVP of coated nylon fabrics decreased with increasing clay content at a fixed temperature," wrote M.M. Rahman and colleagues, Pusan National University ...read more

  2008 DEC 29 - (VerticalNews.com) -- "Mechanical properties and fracture toughness micromechanisms of copolypropylene filled with different amount of nanometric CaCO3 (5-15 wt %) were studied," scientists writing in the Journal of Applied Polymer Science report.

  "J-integral fracture toughness was incorporated to measure the effect of incorporation of nanoparticle into PP matrix. Crack-tip damage zones and fracture Surfaces were studied to investigate the effect of nanofiller content on fracture toughness micromechanisms," wrote R.L. Khosh and colleagues ...read more