In this study, biocomposite based on poly(lactic acid) (PLA) and lotus fiber (LF) was prepared. PLA was plasticized with 4 wt% of polyethylene glycol (PEG). The contents of LFs in the composites were 10, 15 and 20 %. Mechanical and thermal properties and morphology of the PLA/LF composites were investigated. The results showed that LFs significantly improved both tensile strength and elongation at break of the composites, but slightly decreased the thermal stability as compare to neat PLA. SEM analysis results showed that the LF has a rough surface and were well-dispersed in the PLA matrix at the content of 10 and 15 wt%.

Introduction: Helicobacter pylori and Candida albicans are classified as the most common pathogenic agents in humans. H. pylori is responsible for gastroduodenal diseases and greatly associated with gastric carcinogenesis, while C. albicans is the main cause of fungal urinary tract, genital yeast, and fungal skin infections. The increasing appearance of drug-resistant strains of H. pylori and C. albicans has made the treatment of the infections more serious. Hydrosols from plant steam distillation have been traditionally used in medicine, cosmetics, and culinary uses. They have been recently suggested as antimicrobial agents owing to their safety and ability to reduce the potential of resistance. The aim of the present study is to assess antibacterial and antifungal activities of hydrosols extracted from the fresh fruits of Litsea cubeba against H. pylori and C. albicans. Methods: The L. cubeba fruit hydrosol was obtained by steam distillation method. Evaluation of the growth-inhibiting and microbicidal effects of the hydrosol towards the H. pylori ATCC 43504 and C. albicans ATCC 10231 was determined through MIC (minimal inhibitory concentration), MBC (minimal bactericidal concentration), and MFC (minimal fungicidal concentration) measurements using broth dilution assays. Compositions of the dissolved essential oil (dEO) from the hydrosol were analyzed by GC-MS (gas chromatography-mass spectrometry). Results: The results indicated that the L. cubeba fruit hydrosol exhibited strong antimicrobial ability towards the bacterium H. pylori (MIC of 10%, MBC of 30%) and the yeast C. albicans (MIC of 10%, MFC of 40%). The cells of H. pylori and C. albicans were killed completely after 24 and 18 hours of treatment with 30% and 40% of the hydrosol, respectively. The major constituents of the dEO were geranial (32.92%), neral (27.12%), p-menthan-8-yl acetate (8.45%), 2-cyclopropyl-2-methylspiro[2.2]pentane-1-carboxylic acid (8.09%), linalool (4.24%), and methyl heptenone (4.15%). Conclusion: The results of the study suggest that L. cubeba fruit hydrosols could be used as potent natural antibacterial and antifungal preparations in the global effort to discover safe alternatives to toxic antimicrobial agents.

Organometal halide perovskite materials have shown high potential as light absorbers for photovoltaic applications. In this work, perovskite planar solar cells were fabricated on corning substrates with the structure as follows: the first layer made of tantalum-doped tin oxide as transparent contact material, followed by sputtering niobium-doped titanium oxide as the compact electron transport layer; covered with perovskite CH3NH3PbI3 as the light harvester by combination between spin-coating and dipping methods; CuSCN was evaporated as the hole transport layer; the final thin Al/Ag electrodes were deposited. This configuration is shortly described as Al/TTO/NTO/CH3NH3PbI3/CuSCN/Ag. Such heterojunctions are expected to be suitable for the development of efficient hybrid solar cells. The fabricated cells were measured under the air mass 1.5 illumination condition, showed the rectification effect and exhibited a power conversion efficiency of 0.007%, with a open circuit voltage of 53.2 mV, a short circuit current of 0.36 mA/cm2, and a form factor of 37%. The power conversion efficiency will be further optimized in near future.

In this study, MoS2 was composited with RGO (the reduced form of graphene oxide) for enhancing the photocatalytic degradation of RhB in aqueous solution by applying visible light irradiation. A new approach to synthesize graphene was applied by reduction of graphene oxide using ascorbic acid. Factors affecting the photocatalytic degradation including pH, initial rhodamine B concentration, light source intensity and quencher existence were investigated. The results showed that MoS2/RGO composite exhibited better photocatalytic activity in the degradation of RhB (with a conversion of 80 %) compared to pure MoS2 (with a conversion of 30.8 %) under visible light irradiation. The higher photocatalytic performance of MoS2/RGO was found in slight acidic environment. Among the tested free radical killers, ammonium oxalate revealed the most significant effect on the photocatalytic degradation of RhB.This research also indicated that MoS2/RGO composite can be considered as a potential catalyst for the degradation of persistent organic dyes in wastewater.