Biodegradable Electrospun Membranes for Sustainable Industrial Applications.

The escalating demand for sustainable industrial practices has driven the exploration of innovative materials, prominently exemplified by biodegradable electrospun membranes (BEMs). This review elucidates the pivotal role of these membranes across diverse industrial applications, addressing the imperative for sustainability. Furthermore, a comprehensive overview of biodegradable materials underscores their significance in electrospinning and their role in minimizing the environmental impact through biodegradability. The application of BEMs in various industrial sectors, including water treatment, food packaging, and biomedical applications, are extensively discussed. The environmental impact and sustainability analysis traverse the lifecycle of BEMs, evaluating their production to disposal and emphasizing reduced waste and resource conservation. This review demonstrates the research about BEMs toward an eco-conscious industrial landscape for a sustainable future.

Biogenic Synthesis of Nanoparticles from the Edible Plant Polygonum microcephalum for Use in Antimicrobial Fabric.

With increasing demand of the public toward antimicrobial textiles, there should be the proper fabrication of such types of clothes, and it is possible with biogenically synthesized metal nanoparticles (NPs). It is necessary to find cheap and eco-friendly resources for such synthesis. In this work, we used Polygonum microcephalum from Assam, India, to synthesize copper and silver (Ag) NPs. As far as we know, this is the first report on the synthesis of AgNPs and copper oxide NPs (CuONPs) from P. microcephalum The synthesis was done from the aqueous leaf extract. The AgNPs and CuONPs formation was observed by the change in the color of the solution and was confirmed by UV-visible spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Characterization of NPs was done with various physicochemical characterization techniques. The synthesized spherical-shaped AgNPs were found to be effective against the representative bacteria, Gram +ve (Staphylococcus Aureus) and Gram -ve (Escherichia Coli and Pseudomonas Aeruginosa), but the flake-shaped CuONPs were not effective due to their bigger size (>200 nm). The results clearly show that the AgNPs used in this study were toxic against three pathogens. The minimum inhibitory concentrations of AgNPs for S. aureus and E. coli were 32 µg/mL. The uptake analysis of AgNPs for both pathogens demonstrates the mechanism of toxic effects. The present study confirms that P. microcephalum leaf extract is effective in AgNP synthesis, and it could be a cost-effective and environmentally friendly resource for the green synthesis of AgNPs.

A Gemini basic ionic liquid and functionalized cellulose nanocrystal-based mixed matrix membrane for CO2/N2 separation.

Owing to the adverse environmental impact, carbon capture and separation have gained tremendous interest throughout the globe. Herein, a CO2/N2 gas separative mixed matrix membrane containing amine functionalized cellulose nanocrystals and a Gemini basic ionic liquid has been developed, which exhibits the highest permeance of 21 033 GPU and moderate selectivity of 21.3.

Carbon nanomaterials for designing next-generation membranes and their emerging applications.

Carbon nanomaterials have enormous applications in various fields, such as adsorption, membrane separation, catalysis, electronics, capacitors, batteries, and medical sciences. Owing to their exceptional properties, such as large specific surface area, carrier mobility, flexibility, electrical conductivity, and optical pellucidity, the family of carbon nanomaterials is considered as one of the most studied group of materials to date. They are abundantly used in membrane science for multiple applications, such as the separation of organics, enantiomeric separation, gas separation, biomolecule separation, heavy metal separation, and wastewater treatment. This study provides an overview of the significant studies on carbon nanomaterial-based membranes and their emerging applications in our membrane research journey. The types of carbon nanomaterials, their utilization in membrane-based separations, and the mechanism involved are summarized in this study. Techniques for the fabrication of different nanocomposite membranes are also highlighted. Lastly, we have provided an overview of the existing issues and future scopes of carbon nanomaterial-based membranes for technological perspectives.

In-situ biofabrication of bacterial nanocellulose (BNC)/graphene oxide (GO) nano-biocomposite and study of its cationic dyes adsorption properties.

In the present study, bacterial nanocellulose/graphene oxide nano-biocomposites (BNC-GO-NBCs) were fabricated by Komagataeibacter saccharivorans NUWB1 using an in-situ method involving three time-dependent approaches. Physicochemical studies showed that the chosen dried BNC-GO-NBC possessed a three-dimensional interconnected porous structure of BNC with GO layers embedded within the BNC fibrils. BNC-GO-NBC had a crystallinity index of 74.21 %, higher thermostability up to 380 °C and could withstand a tensile load of 84.72 MPa. N2 adsorption-desorption isotherm of the BNC-GO-NBC was found to be of type IV, suggesting a mesoporous type structure with a total pore volume and surface area of 6.232e-04 cc g-1 and 10.498 m2. BNC-GO-NBC exhibited remarkable adsorption capacity for two cationic dyes, Rhodamine B (RhB) and Acridine Orange (AO), and the adsorption data conformed well to the Langmuir isotherm (R2 = 0.99) and pseudo-second-order model. Thermodynamic studies indicated that the adsorption process was spontaneous and endothermic. Additionally, the BNC-GO-NBC displayed the potential for regeneration, with the ability to be recycled up to five times. Further, the antibacterial activity, cell cytotoxicity and oxidative stress assays of the BNC-GO-NBC revealed its non-cytotoxic nature. The findings of the present investigation evidently suggest the potentiality of BNC-GO-NBC in the application of dye adsorption and other environmental applications.

Cellulose nanofiber-poly(ethylene terephthalate) nanocomposite membrane from waste materials for treatment of petroleum industry wastewater.

Petroleum industry wastewater contains high level of crude oil and other types of organic substances that can cause immense harm to the agriculture, aquatic as well as terrestrial organisms. Organic solvent resistance of membranes is very important to treat such wastewater that contains high level of organic pollutants. This work reports the designing of a superhydrophilic and organic solvent resistant nanocomposite membrane using waste bottles made of poly(ethylene terephthalate) (PET) and cellulosic papers. Using in-situ synthesized cellulose nanofibers we could successfully fabricate porous membranes which is not possible for bare PET matrix using water as nonsolvent. Thus, we could successfully replace methanol which was used as a suitable non-solvent in earlier reports by distilled water. We successfully used the membrane for separation of synthetic crude oil-water emulsion. The membrane showed permeability up to 98 Lm-2h-1 applying pressure of 1.5 bar. The membrane also achieved removal of more than 97 % of organic substances from a crude oil-water emulsion system. The optimum membrane also showed good thermal stability with initial degradation temperature ∼350 °C and tensile strength of 0.86 MPa. The antimicrobial property of the nanocomposite membranes could be achieved by coating its surface with carbon dots rooted graphene oxide.

Cellulose nanofiber mediated natural dye based biodegradable bag with freshness indicator for packaging of meat and fish.

This work reports the development of a biodegradable bag with freshness detection property for packaging of fish and meat. A nanocomposite film was prepared using cellulose nanofibers and cellulose acetate. Cellulose nanofibers were synthesized from cellulosic materials extracted from grass. Naturally occurring anthocyanin was introduced to activate the film for ammonia detection. Anthocyanin was extracted from the seeds of a dye bearing plant called Melastoma Malabathricum. Presence of cellulose nanofibers facilitates the absorption of anthocyanin on the film surface. The inherent property of colour changing ability with the change in pH, anthocyanin converts the film into a sensor for ammonia vapour. This colour change ability of the films was characterised using a colour measurement instrument. The film showed a tensile strength of ⁓29 MPa and thermal stability ⁓288 °C. Utilizing the thermoplastic nature of cellulose acetate, such films could be easily converted to a packaging bag by heat sealing.

Development of Antifouling Thin-Film Composite/Nanocomposite Membranes for Removal of Phosphate and Malachite Green Dye.

Nowadays polymer-based thin film nanocomposite (TFN) membrane technologies are showing key interest to improve the separation properties. TFN membranes are well known in diverse fields but developing highly improved TFN membranes for the removal of low concentration solutions is the main challenge for the researchers. Application of functional nanomaterials, incorporated in TFN membranes provides better performance as permeance and selectivity. The polymer membrane-based separation process plays an important role in the chemical industry for the isolation of products and recovery of different important types of reactants. Due to the reduction in investment, less operating costs and safety issues membrane methods are mainly used for the separation process. Membranes do good separation of dyes and ions, yet their separation efficiency is challenged when the impurity is in low concentration. Herewith, we have developed, UiO-66-NH2 incorporated TFN membranes through interfacial polymerization between piperazine (PIP) and trimesoyl chloride (TMC) for separating malachite green dye and phosphate from water in their low concentration. A comparative study between thin-film composite (TFC) and TFN has been carried out to comprehend the benefit of loading nanoparticles. To provide mechanical strength to the polyamide layer ultra-porous polysulfone support was made through phase inversion. As a result, outstanding separation values of malachite green (MG) 91.90 ± 3% rejection with 13.32 ± 0.6 Lm-2h-1 flux and phosphate 78.36 ± 3% rejection with 22.22 ± 1.1 Lm-2h-1 flux by TFN membrane were obtained. The antifouling tendency of the membranes was examined by using bovine serum albumin (BSA)-mixed feed and deionized water, the study showed a good ~84% antifouling tendency of TFN membrane with a small ~14% irreversible fouling. Membrane's antibacterial test against E. coli. and S. aureus. also revealed that the TFN membrane possesses antibacterial activity as well. We believe that the present work is an approach to obtaining good results from the membranes under tricky conditions.