More than 320 million tons of plastics are produced annually, and the rate of plastic waste generation steadily increases by 3.9% per year. Introduction of plastic waste into water bodies may lead to many adverse environmental impacts as the plastic debris is very stable and generally requires a longer time to degrade. Over a period of time, bulk plastic debris will slowly degrade into small fragments known as macroplastics (particles size >5mm) and microplastics (particles size <5mm). Accumulation of this newly emerging class of pollutants potentially decreases the efficiency of the existing water treatment system. Therefore, improvement on the existing water treatment technique is required. This study aimed at investigating the effect of using the UV-assisted thermo-photocatalytic reaction on the degradation of polypropylene (PP) macro- and microplastics in an aqueous environment for 6 hours. ZnO nanoparticles (<50 nm) were employed as the photocatalyst. 23 Full Factorial design was carried out in order to identify the correlation between the reaction temperature (35-50 o C), size of PP plastic (25-100 mm2 ) and the catalyst dosage (1–3 g/L) factors and their influences on the weight loss of macro/micro-plastics. Maximum plastic weight loss of 7.8 wt% was achieved at 50°C, 1 g/L ZnO and 25 mm2 of PP plastic. The interaction between temperature and size must be taken into consideration.

High demands on low-voltage electronics have increased the need for zinc oxide (ZnO) varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr₆O₁₁) based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr₆O₁₁ addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr₆O₁₁ from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, α, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and α lowering with increasing Pr₆O₁₁ content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary.

With the trend for green technology, the study focused on utilizing a forgotten herb to produce an eco-friendly coating. Andrographis paniculata or the kalmegh leaves extract (KLE) has been investigated for its abilities in retarding the corrosion process due to its excellent anti-oxidative and antimicrobial properties. Here, KLE was employed as a novel additive in coatings and formulations were made by varying its wt%: 0, 3, 6, 9, and 12. These were applied to stainless steel 316L immersed in seawater for up to 50 days. The samples were characterized and analyzed to measure effectiveness of inhibition of corrosion and microbial growth. The best concentration was revealed to be 6 wt% KLE; it exhibited the highest performance in improving the ionic resistance of the coating and reducing the growth of bacteria.