Cost-effective, clean, highly transparent, and flexible as well as a coatable packaging material is envisioned to solve or at least mitigate quality preservation issues of organic materials, originating from moisture interaction under ambient conditions. Liquid phase processing of packaging coatings using nano-clay and polyvinyl alcohol (PVOH) has been developed and reported. Detailed analysis of the developed coating revealed moisture permeability of 2.8 × 10−2 g·cm/m2·day at 40 °C and 85% relative humidity (RH), which is in close accordance with Bharadwaj’s theoretical permeability model. Moreover, the developed coatings are not only more than 90% transparent, when exposed to white light, but also exhibit excellent flexibility and even after going through 10,000 bending cycles maintained the same blocking effect against moisture.

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Silica is one of the most efficient gas barrier materials, and hence is widely used as an encapsulating material for electronic devices. In general, the processing of silica is carried out at high temperatures, i.e., around 1000 °C. Recently, processing of silica has been carried out from a polymer called Perhydropolysilazane (PHPS). The PHPS reacts with environmental moisture or oxygen and yields pure silica. This material has attracted many researchers and has been widely used in many applications such as encapsulation of organic light-emitting diodes (OLED) displays, semiconductor industries, and organic solar cells. In this paper, we have demonstrated the process optimization of the conversion of the PHPS into silica in terms of curing methods as well as curing the environment. Various curing methods including exposure to dry heat, damp heat, deep UV, and their combination under different environments were used to cure PHPS. FTIR analysis suggested that the quickest conversion method is the irradiation of PHPS with deep UV and simultaneous heating at 100 °C. Curing with this method yields a water permeation rate of 10−3 g/(m2⋅day) and oxygen permeation rate of less than 10−1 cm3/(m2·day·bar). Rapid curing at low-temperature processing along with barrier properties makes PHPS an ideal encapsulating material for organic solar cell devices and a variety of similar applications.

The majority of food packaging materials are petroleum-based polymers, which are neither easily recyclable nor ecologically friendly. Packaging films should preferably be transparent, light in weight, and easy to process, as well as mechanically flexible, and they should meet the criteria for food encapsulation. In this study, poly (vinyl alcohol) (PVA)-based films were developed by incorporating glass flakes into the films. The selection of PVA was based on its well-known biodegradability, whereas the selection of glass flakes was based on their natural impermeability to oxygen and moisture. The films were processed using the blade coating method and were characterized in terms of transparency, oxygen transmission rate, mechanical strength, and flexibility. We observed that the incorporation of glass flakes into the PVA matrix did not significantly change the transparency of the PVA films, and they exhibited a total transmittance of around 87% (at 550 nm). When the glass flakes were added to the PVA, a significant reduction in moisture permeation was observed. This reduction was also supported and proven by Bhardwaj’s permeability model. In addition, even after the addition of glass flakes to the PVA, the films remained flexible and showed no degradation in terms of the water vapor transmission rate (WVTR), even after bending cycles of 23,000. The PVA film with glass flakes had decent tensile characteristics, i.e., around >50 MPa. Increasing the concentration of glass flakes also increased the hardness of the films. Finally, a piece of bread was packaged in a well-characterized composite film. We observed that the bread packaged in the PVA film with glass flakes did not show any degradation at all, even after 10 days, whereas the bread piece packaged in a commercial polyethylene bag degraded completely. Based on these results, the developed packaging films are the perfect solution to replace commercial non-biodegradable films.

Implants are used to replace damaged biological structures in human body. Although stainless steel (SS) is a well-known implant material, corrosion of SS implants leads to the release of toxic metallic ions, which produce harmful effects in human body. To prevent material degradation and its harmful repercussions, these implanted materials are subjected to biocompatible coatings. Polymeric coatings play a vital role in enhancing the mechanical and biological integrity of the implanted devices. Zein is a natural protein extracted from corn and is known to have good biocompatibility and biodegradability. In this study, zein/Ag-Sr doped mesoporous bioactive glass nanoparticles (Ag-Sr MBGNs) were deposited on SS substrates via electrophoretic deposition (EPD) at different parameters. Ag and Sr ions were added to impart antibacterial and osteogenic properties to the coatings, respectively. In order to examine the surface morphology of coatings, optical microscopy and scanning electron microscopy (SEM) were performed. To analyze mechanical strength, a pencil scratch test, bend test, and corrosion and wear tests were conducted on zein/Ag-Sr doped MBGN coatings. The results show good adhesion strength, wettability, corrosion, and wear resistance for zein/Ag-Sr doped MBGN coatings as compared to bare SS substrate. Thus, good mechanical and biological properties were observed for zein/Ag-Sr doped MBGN coatings. Results suggested these zein/Ag-Sr MBGNs coatings have great potential in bone regeneration applications.