Biodegradation of lactic acid and polyethylene glycol based polyester urethanes

221-228A novel polyester urethane based on lactic acid and polyethylene glycol 400 (PEG400) was synthesized. The biodegradation of the polyester urethane under soil burial condition and by cultured bacteria (Pseudomonas aeruginosa) at different temperatures (5, 15, 37ºC) was studied. The biodegradation was assessed from the weight loss, tensile strength and ultimate elongation as well as chemical changes by FTIR spectroscopy and visual changes by optical and scanning electron microscopy. After 30 days of exposure of the polyester urethane films to cultured Pseudomonas aeruginosa around 33-36% degradation in terms of weight loss was observed. Under soil burial degradation the samples have shown 62% weight loss in 180 days but there is around 98 to 99% loss in tensile strength and elongation at break

Monitoring of drinking water quality: a preliminary approach by an electronic tongue based on functionalized polymer membrane electrodes

Functionalized polymer membrane electrodes based multichannel sensor is used as an electronic tongue to monitor the drinking water (DW) quality simply by measuring the surface electric potential with respect to Ag/AgCl reference electrode in 1 mM aqueous KCl.</p

Taste sensing with polyacrylamide grafted cellulose

237-243The research work covers polymer membrane preparation, morphology study, and structural characterization of the membrane and study of the taste sensing characteristics of membrane for five different taste substances. FTIR spectroscopic analysis, UV spectroscopic analysis and SEM were carried for the structure and morphology of polyacrylamide (PAM) grafted cellulose membrane. Sensor characteristics (temporal stability, response stability, response to different taste substances, and reproducibility of sensing performance) were studied using PAM grafted cellulose membrane. Sensor device prepared with this membrane showed distinct response patterns for different taste substances in terms of membrane potential. Threshold concentrations of PAM grafted cellulose membrane are below human threshold concentrations and are as follows: HCl, 0.008; NaCl, 0.05; Q-HCl, 0.001; sucrose, 0.008; and monosodium glutamate (MSG), 0.05 mM. Membranes also showed characteristic response patterns for organic acids (acetic acid, citric acid, formic acid etc.), mineral acids (HCl, H2SO4, HNO3), salts, bitter substances, sweet substances and umami substances. Sensor device prepared with this membrane has excellent shelf life

Polyvinyl alcohol-cellulose composite: a taste sensing material

Abstract. There are reports of fabrication of taste sensor by adsorbing lipids into Millipore filter paper. With this lipid based sensor, it has been found that the taste sensing efficiency of membrane can be remarkably improved. We have made an attempt to prepare taste sensor material by using functionalized polymer without any lipid. PVA–cellulose composite has been modified to use as the sensor material. The research work covers polymer membrane preparation, morphology study and structural characterization of the membrane and study of the taste sensing characteristics of this membrane for five different taste substances. PVA–cellulose composite membrane was modified by phosphorylation with POCl3. FTIR spectroscopic analysis, XRD analy-sis and SEM were done to get an idea about the structure and morphology of the prepared phosphorylated PVA–cellulose composite membrane. The sensor characteristics like temporal stability, response stability, res-ponse to different taste substances, and reproducibility of sensing performance were studied using phosphory-lated PVA–cellulose composite membrane. Sensor device prepared with this membrane has shown distinct response patterns for different taste substances in terms of membrane potential. Threshold concentrations of phosphorylated PVA–cellulose composite membrane for HCl, NaCl, Q-HCl, sucrose and MSG are 0×0 1 mM, 0×001 mM, 0×001 mM, 0×001 mM and 0×009 mM, respectively. The threshold concentrations are below human threshold concentrations. Membranes also showed characteristic response patterns for organic acids like ace-tic acid, citric acid, formic acid etc, mineral acids like HCl, H2SO4 and HNO3 salts, bitter substances, sweet substances and umami substances. Sensor device prepared with this membrane has excellent s elf life