Functionalization of cellulosic and polyester textiles using reduced Schiff base (RSB) of eco-friendly vanillin.

Vanillin is an active ingredient found in the crop 'vanilla' and is traditionally extracted from the 'vanilla pod'. Vanillin intrinsically is not a suitable candidate for imparting durable functional features into textile substate due to its smaller chemical structure which leads to leaching of the same during washing operation. To enlarge the structure, in the present study, vanillin has been converted into 4-(benzylamino) methyl))-2-methoxyphenol vanillin derivative (reduced Schiff base) with considerable amount of yield by using a simple one-step process and the synthesized product has been characterized by 1H, C13 NMR, FTIR, and Raman analysis. Thereafter, the reduced Schiff base of vanillin (RSB) has been integrated on cotton as well as polyethylene terephthalate (PET) fabric using high temperature high pressure (HT-HP) technique for imparting multiple functionalities. FESEM EDX analysis has confirmed the integration of RSB on both the fabrics by revealing uniform presence of the nitrogen (of the synthesized derivative) on the treated textile materials. Both types of functionalized textiles have demonstrated appealing color shades with an excellent antimicrobial activity of about 90% against Escherichia coli (E. coli) bacteria. The treated fabrics could cater pleasing fragrance and exhibit 90% antioxidant properties. Moreover, enlarged vanillin derivative in the form of RSB can retain its properties in the fabrics even after repeated machine launderings. RSB-treated cotton fabric has shown ultra-violet protection factor (UPF) of 38 which drops to 24 after washing whereas in case of PET treated fabric, the observed UPF values are 265 and 164 before and after washing, respectively. The RSB treatment has been found to be cytotoxically secure and biocompatible as tested on the PET fabric. Other required properties of the treated fabrics such as water absorbency, flexibility, etc. have also been found to be intact. Thus, the presented study reveals a new class of safe material that can be derived from eco-friendly vanillin and has the potential to replace hazardous chemicals that are currently used in textile chemical processing industries. Supplementary Information: The online version contains supplementary material available at 10.1007/s10570-023-05085-z.

Investigating the role of carbon nanotubes (CNTs) in the piezoelectric performance of a PVDF/KNN-based electrospun nanogenerator.

In the present study, the effect of varying the concentration of carbon nanotubes (CNTs) on the piezoelectric performance of a poly(vinylidene fluoride) (PVDF)/potassium sodium niobate (KNN)-based electrospun nanocomposite has been revealed. The incorporation of 0.1% CNTs in the PVDF/KNN composite results in a significant improvement in the performance of the nanogenerator, with an output voltage of ∼23.24 V, a current of ∼9 µA and a power density of 52.29 µW cm-2 under finger tapping compared with a voltage of ∼12 V, a current of ∼18 µA and a power density of 54 µW cm-2 upon the application of a mechanized compressive force. In fact, the addition of CNTs led to a higher ß-fraction in the hybrid nanocomposite. Moreover, the presence of CNTs creates a conducting path in the nanofiller loaded polymer jet, which results in enhanced mechanical stretching of the electrospun fibres. This hybrid lead-free nanogenerator could be a good candidate for use in self-powered portable and wearable electronic goods where a very small amount of power is required.

Antimicrobial Nanomaterials as Advanced Coatings for Self-Sanitizing of Textile Clothing and Personal Protective Equipment.

Controlling bioaerosols has become increasingly critical in affecting human health. Natural product treatment in the nano form is a potential method since it has lower toxicity than inorganic nanomaterials like silver nanoparticles. This research is important for the creation of a bioaerosol control system that is effective. Nanoparticles (NPs) are gradually being employed to use bacteria as a nonantibiotic substitute for treating bacterial infections. The present study looks at nanoparticles' antimicrobial properties, their method of action, their impact on drug-opposing bacteria, and the hazards connected with their operation as antimicrobial agents. The aspects that influence nanoparticle conduct in clinical settings, as well as their distinctive features and mode of action as antibacterial assistants, are thoroughly examined. Nanoparticles' action on bacterial cells is presently accepted by way of the introduction of oxidative stress induction, metal-ion release, and nonoxidative methods. Because many concurrent mechanisms of action against germs would necessitate multiple simultaneous gene modifications in the same bacterial cell for antibacterial protection to evolve, bacterial cells developing resistance to NPs is difficult. This review discusses the antimicrobial function of NPs against microbes and presents a comprehensive discussion of the bioaerosols: their origin, hazards, and their prevention. This state of the art method is dependent upon the use of personal protective gear against these bioaerosols. The benefit of the utmost significant categories of metal nanoparticles as antibacterial agents is given important consideration. The novelty of this review depends upon the antimicrobial properties of (a) silver (Ag), (b) zinc oxide (ZnO), and (c) copper oxide (CuO) nanoparticles. The value-added features of these nanoparticles are discussed, as well as their physicochemical characterization and pharmacokinetics, including the toxicological danger they pose to people. Lastly, the effective role of nanomaterials and their future in human wellness is discussed.

Green synthesis of sodium lignosulfonate nanoparticles using chitosan for significantly enhanced multifunctional characteristics.

Nanoparticles of green materials have gained enormous interest due to their broad range of applications in several disciplines since they have significantly improved multifunctional activities. This article attempts a sustainable green approach to synthesize sodium lignosulfonate nanoparticles (SLS NPs) using another biomolecule, i.e., chitosan. The synthesized SLS NPs (with an average diameter of ~125 nm to 129 nm) have demonstrated synergetic efficacy by exhibiting outstanding multifunctional properties due to the presence of two types of biomolecules (i.e., lignosulfonate as well as chitosan) in their structure. The synthesized SLS NPs have bestowed excellent antibacterial activity against both the Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. Moreover, SLS NPs have displayed ~92% antioxidant property. Having polyphenolic entities in the structure of SLS NPs, they have shown UV-visible absorption peak at 224 nm, which directly indicates that they can act as an outstanding UV protective agent which has also been proven experimentally.

A fully sustainable, self-poled, bio-waste based piezoelectric nanogenerator: electricity generation from pomelo fruit membrane.

A self-powered system is very much essential aspect in the recent trend to improve the working efficiency of the portable and wearable devices. Here, we have reported a fully sustainable, self-poled, bio-compatible, and bio-waste based piezoelectric energy harvester which has been made of Pomelo Fruit Membrane (PFM). PFM based piezoelectric generator (PFMBPEG) could generate ~ 6.4 V output voltage and ~ 7.44 µA output current directly, only by finger tapping on the device and registers a power density of ~ 12 µW cm-2 whereas, the same piezoelectric generator can generate ~ 15 V output voltage, 130 µA output current, and power density of ~ 487.5 µW cm-2 by using a full wave rectifier. The sensitivity and energy harvesting competence of the generator have also been assessed by attaching this nanogenerator into various parts of human body (as energy sources) such as wrist, elbow, finger, throat, jaws, leg and putting the device into ultrasonic bath and in every case, it could successfully generate voltage. Therefore, this bio-waste based energy harvester can be used as a power source for the different potable and wearable electronic goods where a small amount of energy is required, specifically in the biomedical applications (i.e., health monitoring, power source for the implantable devices and so on). Finally, mechanical stability the developed piezoelectric generator has been evaluated by cyclic bending test and it has been observed that there is no significant deformation of the PFM film even after 100 cycles.

Leveraging antibacterial efficacy of silver loaded chitosan nanoparticles on layer-by-layer self-assembled coated cotton fabric.

The present study relates to form a self-assembled coating on cotton fabric using layer-by-layer (L-B-L) technique to impart antimicrobial property. Poly(styrenesulfonate) (PSS) and synthesised silver loaded chitosan (CS-Ag) nanoparticles were used as anionic and cationic agents, respectively, for the L-B-L electrostatic assembly of polyelectrolytes. The alternate L-B-L deposition of PSS and CS-Ag nanoparticles on fabric was done up to 15 bi-layers, which was confirmed by measuring the change in depth of colour of fabric after each single layer deposition. Scanning electron micrographs showed the successful deposition of CS-Ag nanoparticles as the topmost surface layer of coated fabric, which was further reaffirmed by X-ray photoelectron spectroscopy analysis. Results of both qualitative and quantitative analysis showed enhancement in the antibacterial activity of fabric coated L-B-L with CS-Ag nanoparticles (using minimal loading of silver) with respect to that of fabric coated L-B-L with chitosan (CS) nanoparticles. This was further substantiated by sustained release of Ag+ from fabric coated L-B-L with CS-Ag nanoparticles, as observed by atomic absorption spectroscopy. Besides, no adverse effect on the physical and mechanical properties of the fabric, such as air-permeability, tensile strength and bending (flexural) rigidity, was observed after L-B-L coating of nanoparticles.