Concerning the importance of composite material for multi-purpose applications, an attempt has been taken to synthesize composites using natural fiber with unsaturated polyester resin. Since the use of synthetic polymer plays a key role in polluting the environment, we have used natural fiber (banana fiber) as an alternative source. Our approach dealt with the preparation of reinforced composites by hand lay-up technique using 20 % banana fiber (by weight) as reinforcing materials. Several techniques were applied to characterize synthesized composites e.g. universal testing machine (UTM), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). UTM facilitated the measurement of the tensile strength (TS), tensile modulus (TM), elongation at break (EB), bending strength (BS), and bending modulus (BM) while functional groups were confirmed by FT-IR and the morphology of the composites was investigated by SEM. Observed results revealed that the TS, TM, BS, and BM followed an increasing fashion of 100%, 53%, 75%, and 55% respectively with respect to the matrix materials. On the other hand, the EB of the composite reduced drastically by 50%. Hence, higher mechanical properties were obtained for the banana fiber reinforced composites (BFRC) than the unsaturated polyester resin (UPR) matrix.

Over the past few years, activated carbon (AC) has attained significant attention as an efficient adsorbent for heavy metal (lead, cadmium, chromium etc.) removal. In Bangladesh, bagasse and jute fibre are the two most potential raw materials for producing activated carbon due to their high availability and low cost. The activated carbon was produced by thermal treatment method. The produced AC were characterized using FTIR, XRD, SEM etc. Batch experiments under agitation was also carried out for adsorption of heavy metals and then characterized using AAS (Atomic Adsorption Spectroscopy). Adsorption with commercially available activated carbon was also done to use as standard. Among all ACs produced in this study, the highest percentage removal of heavy metals which were Cr3+ and Cd2+ was at 57.06% and 43.01% respectively for J-400 ( AC produced from jute fibre at 4000C). This obtained value was 16.6% and 12.9% higher in comparison to Commercially available Activated carbon for Cr3+ and Cd2+ respectively.

Biopolymer carboxymethyl tamarind seed kernel polysaccharide (CMTSP) was synthesized by the reaction of tamarind kernel powder (TKP) of Tamarindus indica L. with monochloroacetic acid by an improved method. The synthesis was conducted in presence of sodium hydroxide at optimized conditions of time, temperature, concentrations of TKP, MA, sodium hydroxide. Tamarind seed polysaccharide (TSP) was also extracted from TKP by boiling distilled water. The chemical structure of TKP, TSP and CMTSP were analyzed by the ATRFTIR. When TKP, TSP, and CMTSP’s comparative physico-mechanical properties were examined and compared, CMTSP performed better due to increase in viscosity, water solubility and tensile properties.

Polymeric proton exchange membranes (PEMs) are vital components of fuel cells, as they enable the transport of protons while preventing the crossover of fuel and oxidant gases. However, conventional PEMs have limitations such as low use temperature, low proton conductivity, and poor mechanical and thermal stability. Various types of nanoparticles have been investigated to modify PEMs to overcome these limitations, as they can increase proton conductivity, mechanical strength, thermal stability, and chemical resistance. Metal oxides such as SiO2 and TiO2 have been shown to improve the proton conductivity and mechanical properties of PEMs. Carbon-based materials such as graphene oxide have been found to enhance both the proton conductivity and thermal stability of PEMs. The use of nanoparticles in modified polymeric PEMs for fuel cells shows excellent potential for improving the performance and durability of fuel cells. Future research should focus on developing cost-effective and scalable methods for nanoparticle synthesis and incorporation into PEMs. Polybenzimidazole (PBI) is the most widely studied high-temperature polymer for preparing composite PEMs. This review provides the recent development of PBI composite PEMs modified with different types of nanoparticles.