Cochin University of Science and Technology

About: Cochin University of Science and Technology is a education organization based out in Kochi, Kerala, India. It is known for research contribution in the topics: Thin film & Natural rubber. The organization has 5382 authors who have published 7690 publications receiving 103827 citations. The organization is also known as: CUSAT & Cochin University.

Biodegradation of polyvinyl alcohol-low linear density polyethylene-blended plastic film by consortium of marine benthic vibrios

Abstract: Marine bacteria, Vibrio alginolyticus and Vibrio parahemolyticus isolated from sediments were evaluated for their ability as a consortia, to degrade polyvinyl alcohol-low linear density polyethylene (PVA-LLDPE)-blended plastic films in shake flask conditions at 120 rpm at 37 °C over 15 weeks. Results indicated that relatively 20 % decrease in tensile strength of the film could be achieved with 25 and 30 % blend of PVA in the PVA-LLDPE plastic film compared to other ratios. Micrographs obtained with scanning electron microscope showed visible cracks and grooves on the surface of the PVA-LLDPE blend film after 15 weeks of incubation with bacterial consortium. The decrease in tensile strength of the PVA-blended plastic films after treatment and the results of the scanning electron microscopic analysis evidence that the consortium could cause degradation of PVA-LLDPE plastic blends compared to suitable controls. This is the first report on polyvinyl alcohol degrading Vibrio sp. from marine sediments and its application in microbial degradation of polyvinyl alcohol-low linear density polyethylene plastic blends. The study indicated potential of marine benthic vibrios that have novel enzymes and unique characteristics for application in bioremediation and solid waste management particularly in handling synthetic polymers such as PVA-blended plastic films.

Development of an Electrochemical Sensor for the Determination of Amaranth: a Synthetic Dye in Soft Drinks

Abstract: The voltammetric behaviour of synthetic food colourant, amaranth, was studied using a multiwalled carbon nanotube (MWCNT) thin film-modified gold electrode in 0.1 M acetate buffer solution of pH 5.0. A well-defined oxidation peak was obtained for amaranth at 0.792 V with the modified electrode. The diffusion controlled oxidation of amaranth at the modified electrode can be attributed to the electrocatalytic nature of MWCNT, since the bare electrode has not produced an electrochemical signal under the same experimental conditions. The operational parameters such as supporting electrolyte, pH of the solution and amount of MWCNT–Nafion suspension were optimised. Under optimum conditions, the oxidation peak current varies linearly with concentration in the range from 1.0 × 10−5 M to 1.0 × 10−6 M with a limit of detection at 6.8 × 10−8 M. The developed sensor has good sensitivity and selectivity towards oxidation of amaranth. The sensor was successfully employed for the determination of amaranth in three different samples of soft drinks, and the results were in good agreement with the standard spectrophotometric method.

Morphology and mechanical properties of thermoplastic elastomers from nylon‐nitrile rubber blends

Abstract: Nylon-nitrile rubber blends having different plastic-rubber component ratios (100/0, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, 20/80, and 0/100) were prepared by melt mixing technique in a Rheocord-90 at a temperature set at 180°C. The mixing characteristics of the blends have been analyzed from the rheographs. The morphology of the blend was studied using optical and electron microscopies, with special reference to the effect of blend ratio. The micrographs indicate a two-phase system where the component having lower proportions was found to disperse in the major continuous phase. A cocontinuous morphology was observed for 50/50 composition. Mechanical properties of the blends have been measured according to standard test methods. The effect of blend ratio on the mechanical properties like tensile strength, tear strength, elongation at break, stress-strain behavior, and hardness has been analyzed. The influence of the strain rate on the mechanical properties has also been analyzed. The mechanical properties were found to have a strong dependence on the amount of nylon in the blend. It is found that the blends with higher proportions of nylon have superior mechanical properties. The observed changes in mechanical properties are explained on the basis of the morphology of the blend. Various theoretical models such as Series, Parallel, Halpin-Tsai, and Coran's equations have been used to fit the experimental mechanical data. © 1996 John Wiley & Sons, Inc.