The mechanical, thermal, swelling, and release properties of chitosan-gelatin (CG) films have been investigated in order to verify the influence of UV and gamma radiation on the stability of the films. Thin films of chitosan and gelatin (1 : 3, w/w) that were radiated with 100 krad of gamma dose showed the best performance and the TS values reached 25, 45, and 49 MPa, respectively, for chitosan, gelatin, and blend. The corresponding highest TS values were 23, 42, and 45 MPa, respectively, for 10 passes of UV radiation. The effect of radiation over gelatin, chitosan, and CG blend caused modification in the arrangement of molecules in the crystal lattice that is significant by XRD analysis. Surfaces of the films were also investigated by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) studies further revealed structural changes of the films. These changes were attributed to understanding the behavior of the irradiated chitosan, gelatin, and CG blend on application of thermal energy using DSC and TGA studies, water uptake of the films in aqueous medium, and soil degradation properties to observe the best possibility for its application.

No abstract

Catalytic pyrolysis of waste plastics into liquid hydrocarbon was conducted in a locally-made stainless steel reactor. Mesoporous kaolin clay treated with sulfuric acid in the concentration range of 3-7 M was used as a catalyst and waste polyethylene was the plastic feed. The X-ray powder diffraction (XRPD) pattern showed that the raw kaolin clay is crystalline. However, XRPD patterns of H2SO4 acid treated kaolin and Ni and Ru metal impregnated H2SO4 treated kaolin did not exhibit any characteristic diffraction peaks of kaolin. The acid treatment of kaolin causes leaching of Al3+ and results in disintegration of layered structure of kaolin, leading to the formation of Al2(SO4)3, SiO2, and amorphous phase. After 5 M H2SO4 acid treatment, the content of Al2O3 decreased significantly to 18.62%. The Si/Al ratio and specific surface area were found to increase after 5 M sulfuric acid treatment from 1.79 to 3.48 and 6.85 m2/g to 17.92 m2/g, respectively. The nitrogen adsorption-desorption isotherms of the 5 M H2SO4 acid treated kaolin clay showed the isotherm to be of type IV typical for mesoporous structure. Among 3, 5, and 7 M H2SO4 treated kaolin catalysts, the 3 M H2SO4 treated kaolin (at a catalyst to plastic feed ratio of 1:5) exhibited the highest activity with the yield of 83% liquid hydrocarbon. The Ru- and Ni-impregnated 5 M H2SO4 treated kaolin catalyst provided 76% and 79% yield, respectively of liquid hydrocarbon at a catalyst to plastic ratio of 1:5. The gas chromatography-mass spectrometry (GC-MS), 1H NMR, and FTIR spectral analysis confirmed the presence of linear and branched alkanes and alkenes (C9-C20) in the end product obtained with 5 M H2SO4 treated kaolin catalyst. The produced liquid hydrocarbon was found to be free from aromatic compounds importantly polycyclic aromatic hydrocarbons which are potent mutagenic and carcinogenic. Journal of Bangladesh Academy of Sciences, Vol. 44, No. 1, 1-12, 2020

No abstract

Results on the applicability of microwave assisted synthesized poly(diallyldimethyl ammonium chloride) (polyDADMAC) in reactive dye containing textile wastewater treatment are reported. Diallyldimethylammonium chloride and poly(diallyldimethylammonium chloride) have been characterized by spectral means. The microwave assisted synthesized polyDADMAC has shown some effectiveness in textile wastewater treatment. COD removal efficiency of actual textile wastewater is below 30% whereas the standard dye sample shows about 50-60% COD removal efficiency. TDS and TSS also decreased after treatment of the wastewater with polyDADMAC.