Abstract: Abstract Thin films of polyvinyl alcohol (PVA) loaded with various concentrations of (f-MWCNTs) were prepared via the regular casting method. The physicochemical characteristics of pure and PVA/f-MWCNTs films were investigated with various techniques; X-ray diffractometer (XRD), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy (UV-Vis), and thermogravimetric analysis (TGA). Moreover, the impact of loading ratios of f-MWCNTs on the dielectric constant and AC conductivity of the PVA/f-MWCNTs nanocomposite film was examined. XRD results suggest a possible improvement in the crystallinity of the PVA/f-MWCNTs composite film compared to a pristine one. Also, FTIR and XPS results confirm the formation of a hydrogen bond between PVA chains and f-MWCNTs. The optical band gaps of the PVA/f-MWCNTs composite film decrease, while the optical conductivity (σ opt ), dielectric constant (έ), and AC conductivity increase with increasing wt% of f-MWCNTs in the PVA matrix. Further, the thermal stability of PVA/f-MWCNTs films improved in comparison with that of PVA film.

Abstract: Abstract This article provides a brief review of conjugated polymers and the various typical polymerization reactions exploited by the community to synthesise different conjugated polyelectrolytes with varied conjugated backbone systems. We further discuss with detailed emphasises the mechanism involved such as photo-induced electron transfer, resonance energy transfer, and intra-molecular charge transfer in the detection or sensing of various analytes. Owing to their excellent photo-physical properties, facile synthesis, ease of functionalization, good biocompatibility, optical stability, high quantum yield, and strong fluorescence emission. Conjugated polymers have been explored for wide applications such as chemical and biological sensors, drug delivery and drug screening, cancer therapeutics and imaging. As such we believe it will be a timely review article for the community.

Abstract: Abstract Sericin has been used in functional and potentially biodegradable materials for cosmetics, biomedical, agricultural, and food applications. It is a natural polymer with applications in absorbent materials, such as hydrogels, because of its hydrophilic character. However, sericin by itself is brittle, and in contact with water has low structural stability, being necessary its blending with other polymers or the application of crosslinking processes. In this work, hydrogel films were prepared from different mixtures containing sericin (SS), carboxymethylcellulose (CMC), and polyvinyl alcohol (PVA), using a simple and environmentally friendly method consisting of a gelling process followed by solvent casting. A mixture design was applied to assess the incidence of each component and its interaction with the output variables of interest. Two response variables were evaluated in each formulation: water absorption capacity (WA) and gel fraction (GF). It was also possible to model the output variables based on the proportions of the sample components. In addition, a set of formulations were used to produce hydrogels with high water absorption rates while maintaining their structural stability. The optimal hydrogel formulation (HF) was structurally and thermally characterized by FTIR and TGA, respectively. Hydrogel morphology was also studied by scanning electron microscopy (SEM). The results of this study constitute an important contribution to the design of novel processing routes to extend the use of silk sericin in the development of new materials.

Abstract: Abstract This paper explores the effect of nanoclay for improving the interfacial properties of starch bioplastic material filled with cellulose-nanoparticles (CNPs). The CNPs were prepared through acid-hydrolysis process by using acid concentration to break the amorphous region of chopped fiber to produce nano-cellulose. Various CNPs concentration (0.5 – 2.5 wt.%) were dispersed in cornstarch biopolymer matrix to form bioplastic films through solution casting method and listed for thermal and mechanical properties. Cornstarch bioplastic filled with 1.5 wt.% of CNPs showed optimum improvement in thermal and mechanical properties. Furthermore, nanoclay (NC) of varying weight percentage (0.1 – 0.5 wt. %) were added to the optimum improved 1.5 wt.% CNPs filled cornstarch bioplastic material. Hence, the hybrid cellulose-nanoparticles/nanoclay (CNPs/NC) filled cornstarch was improved both thermally and mechanically. The stiffness parameter ( $${\beta }_{f}$$ β f ) and confinement region ( $$C$$ C ) of the bioplastic during relaxation stage were 0.70 and 1.03 respectively for hybrid fillers at 1.5/0.3_CNPs/NC, which is an indication that nanoclay had a very good reinforcing effect on the starch polymer system. Improved tensile modulus and tensile strength of the CNPs/NC by 639% and 97% respectively were found when compared to CNPs filled cornstarch bioplastic material. Furthermore, the addition of nanoclay slow down the effect of water absorption rate. Hence, the water uptake of the bioplastic film was normalized.