Studies on cellulose acetate–polysulfone ultrafiltration membranes: I. Effect of polymer composition

Ultrafiltration techniques have particular advantages for simultaneous purification, concentration and fractionation of macromolecules. Studies are presented on novel ultrafiltration membranes, based on cellulose acetate and polysulfone blends, for the separation of proteins and heavy metal ions. The effects of polymer composition on pure water flux, water content, molecular weight cut‐off and hydraulic resistance are discussed. Scanning electron microscopy images of the membranes show the presence of segregated individual domains of cellulose acetate and polysulfone. The molecular weight cut‐off obtained from the protein separation studies is also presented. Applications of these membranes for separating metal ions from aqueous streams are discussed. Copyright © 2005 Society of Chemical Industry     

Site‐specific delivery of green tea coated aluminium magnesium silicate beads and studies on their effect against chicken coccidiosis

In this report, the site‐specific co‐delivery of green tea/aluminium magnesium silicate (AMS) was reported and the specific target delivery was achieved orally. The new co‐precipitation process was developed to synthesis the green tea/AMS hybrid complex and using energy‐dispersive X‐ray spectroscopy, Fourier‐transform infrared spectroscopy and Raman confirmed its successful synthesis. The blood biocompatibility of the green tea/AMS was tested using chicken blood, and the compound is safe up to 500 mg/ml. After mixed with hydroxypropyl methylcellulose phthalate, the oral beads were synthesised using a linking agent. The oral beads underwent different pH‐based dissolution studies and the results indicated that the beads specifically dissolved in gastric pH (6.5). The pharmaco kinetic studies were performed to estimate the delivery kinetics. The results revealed that the beads underwent as per the Higuchi model. The anticoccidial effects of the beads were tested using chicken. The animal studies were performed in two different modes such as prophylactic treatment and active treatment after Eimeria species challenge. The results indicated that the prophylactic treatment with beads 100% protected the chicken and the active treatment with beads after the Eimeria challenge significantly protected against the intestinal damage and it also enhanced the anticoccidial effect.Inspec keywords: X‐ray chemical analysis, drug delivery systems, pH, drugs, biomedical materials, blood, dissolving, Fourier transform infrared spectra, Raman spectra, aluminium compounds, magnesium compounds, precipitation (physical chemistry), materials preparationOther keywords: prophylactic treatment, active treatment, anticoccidial effect, green tea coated aluminium magnesium silicate beads, chicken coccidiosis, target delivery, Fourier‐transform infrared spectroscopy, blood biocompatibility, chicken blood, hydroxypropyl methylcellulose phthalate, oral beads, pharmacokinetic studies, delivery kinetics, animal studies, site‐specific codelivery, pH‐based dissolution, coprecipitation process, green tea‐AMS hybrid complex, energy‐dispersive X‐ray spectroscopy, Raman spectroscopy, linking agent, gastric pH, Al₂ Mg₃ O₁₈ Si₆ , intestinal damage, Eimeria species, anticoccidial effects, Higuchi model     

Keratin hydrolysate as an exhausting agent in textile reactive dyeing process

Salt is an essential exhausting agent for the dyeing of cotton fabric with reactive dyes. The usage of salt leads to an increased effluent load in terms of total dissolved solids and also limits the opportunities for recycling textile dye house effluents. These effluents are difficult to degrade and their disposal leads to environmental pollution. In the present work, we have prepared keratin hydrolysate (KH) from waste of wool processing industries to reduce the usage of salt in dyeing. The KH was fixed to the cotton fabric at five different add on percentage, and the presence of the KH on the fabric was confirmed by FTIR, TGA and SEM-EDX Studies. The KH-fixed fabrics were further dyed with reactive dyes without addition of salt. The colour strength of the fabric increased up to 91 % to that of the control sample. The studies reveal that the tone of the fabric was not altered and KH usage can significantly reduce salt consumption in reactive dyeing process.     

Multi-signaling detection of Hg2+ and Cu2+ by a ferrocene–pyrazole dyad associated with molecular-scale arithmetic

Ferrocene-based sensor R was synthesized and characterized by spectroscopic methods. The optical, electrochemical and cation-sensing properties of receptor R are presented. Receptor R behaves as a selective multi-channel signaling chemosensor molecule for Hg²⁺ and Cu²⁺ ions in CH₃CN. The binding mode of Hg²⁺ with R was determined by ¹³C NMR titration. Both optical and electrochemical methods were applied for the detection of cations in water sample. The characteristic fluorescence of R with the Cu²⁺ selective ON–OFF and the Hg²⁺ selective fluorescence bathochromic shift can be observed and the concept has been used to construct a combinational logic circuit at the molecular level.     

One-step synthesis and solvent-induced exfoliation of hybrid organic-inorganic phyllosilicate-like materials

A room-temperature sol-gel-based process was used to produce by direct synthesis talc-like organosilicates having hexadecyl or aminopropyl groups pending in the interlayer space. Thermal analyses, Fourier transform infrared and 13C/29Si solid-state nuclear magnetic resonance spectroscopies confirmed the presence of organic moieties bonded to the inorganic network. Exfoliation of these organoclays in polar solvents such as water for the positively charged magnesium phyllo(aminopropyl)silicate, and in low polar solvents such as toluene and chloroform for hydrophobic magnesium phyllo(hexadecyl)silicate, was investigated by TEM. The ability of these layered magnesium organosilicates to exfoliate in appropriate solvents was exploited for the preparation of transparent self-supporting films and ordered macroporous networks using by latex colloidal crystal templates.     

Tethering of Cu(II) Schiff base metal complex on mesoporous material MCM-41: catalyst for Ullmann-type coupling reactions

The siloxane-functioned Cu(II) complex derived from 3-aminopropyltrimethoxysilane, terephthaldehyde and 2-aminophenol was anchored on hexagonal mesoporous silica MCM-41. The MCM-41 and its Schiff base MCM-41 complex was characterized by FTIR, small-angle X-ray diffraction, SEM-EDX, N₂ adsorption and desorption analysis and TGA. The synthesized Cu-Schiff base MCM-41 catalyst has been successfully applied as a catalyst for Ullmann-type coupling reaction of the aryl halides with aryl halides, phenols, amines and N-heterocyclic amines. In the coupling reaction the yields of the products were good and the catalyst was recovered by simple filtration method and can be reused.