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We report the first work on the development of biodegradable acoustic foams from self‐grown bacterial cellulose (BC) from kombucha solution and green processing techniques. Kombucha BC‐agar and kombucha BC‐polyvinyl alcohol foams were fabricated by using slurries of BC pellicles mixed with the additives, froze for 24 h, and recast into foams using the freeze‐drying method. The foams were aerogel‐like with a density 20 kg/m3, thermally stable upto 220 °C, and crystallinity ~74%. Morphological analysis revealed macropores with coarse walls in agar‐based foams, whereas the PVA‐based foams comprised a polydisperse pore network with coarse walls. A broadband absorption was observed with a maximum of 0.4 for the 2.5‐mm‐thick single‐layer foams and 0.9 for the 12‐mm‐thick multilayer foams. The sound absorption was found to be on par with the biodegradable foams of agar and other cellulose‐rich materials such as agricultural residue, yet with a lightweight. Being largely porous, the foams had little transmission loss. As the densities and the crystallinities of these foams are tunable by the addition of other polymers, the results from this study provide scope to explore BC‐based lightweight materials for large‐scale fabrication suitable for sound absorption over specific regimes. [ABSTRACT FROM AUTHOR]

The ability to generate valuable products through oxidation makes it one of the most pivotal industrial processes. While organic oxidants have traditionally been the focus in converting alcohols into carbonyl compounds, inorganic oxidants have been relatively underutilized. In this study, we delve into the influence of Potassium periodate (KIO4) in an acidic environment on the oxidation of selected alcohols, comparing its performance with that of catalyst silver nanoparticles prepared from two distinct plant sources: Madhuca longifolia flowers and Ziziphus jujuba leaves. The reactions were intentionally conducted under conditions that adhere to first-order kinetics. At regular intervals throughout the reaction, iodometric measurements were employed to monitor the progress of the reaction. It was noted that the oxidation rate exhibited a proportional increase corresponding to the concentration of alcohol for all the alcohols examined, while it decreased with an increasing concentration of the oxidant. In contrast, when AgNP catalysts were employed in conjunction with KIO4, significantly higher rate constants were achieved compared to using KIO4 alone. This research underscores the potential of silver nanoparticles prepared from plant sources as effective catalysts for alcohol oxidation, offering promising avenues for the development of more efficient and sustainable oxidation processes in the industry. [ABSTRACT FROM AUTHOR]

Toward identifying environmentally friendly sound‐absorbing materials, the fabrication of biodegradable bagasse foams and their acoustic absorption and transmission loss were investigated. 10‐mm‐thick bagasse foams were fabricated using different concentrations of four non‐carcinogenic surfactants: sodium dodecyl sulfate (SDS), sodium bicarbonate (SB), potassium oleate (PO), and polyoxyethylene sorbitol ester (T20). Electron microscopy revealed that the foams comprised microfibers with a 10%–25% porosity. The foams were found to be thermally stable up to 300 °C. While foams fabricated using SDS were found to have a maximum increment in acoustic absorption (by 200%), those made of T20 had a mild decrease in absorption. The increment in absorption was attributed to the decrease in crystallinity and increase in porosity of microstructure, and the decrement to the decrease in viscous nature. Minimal changes were observed in the transmission loss of the foams. The results presented here demonstrate a simple, scalable green method to fabricate porous biodegradable foams of bagasse, without using any binder or filler, suitable for acoustic insulation that fits sustainable development objectives. [ABSTRACT FROM AUTHOR]