Ultrasonic Bioconversion of Silver Ions into Nanoparticles with Azadirachta indica Extract and Coating over Plasma‐Functionalized Cotton Fabric

Abstract

An ultrasonication approach was adopted for Azadirachta indica driven bioconversion of silver salt into silver nanoparticle (AgNPs). These nanoparticles were coated over plasma functionalized cotton by using a pad dry cure technique. For pre‐coat surface functionalization, the cotton fabric was exposed to an open air single dielectric barrier discharge (DBD). The emission spectrum revealed that DBD consisted of NO, O3, O, O2+ , O+, OH−, N2 and N2+ species. The plasma treatment produced negative radicals on the surface and improved the adhesion of fabric for nanoparticles. The crystallographic analysis revealed cubical structure of nanoparticles with average size of 25 nm. The fabric got fully covered with AgNPs after five pad‐dry cycles. Nanoparticles together with neem extract promoted the antimicrobial activity of the coated fabric. The inhibition zone of the silver coated fabric against E.Coli strains increased from 6 mm to 14 mm. The conductivity of fabric after 3, 5 and 7 cycles remained 2.56× 10−2, 2.63× 10−2 and 2.67× 10−2 Siemens/cm, respectively. The coated fabric showed UV protection factor in the range of 210–269. The transmittance of UV−A radiations and UV−B radiations from the uncoated fabric was 19.27 % and 7.84 %, respectively, which reduced to 0.76 % and 0.24 % after 7 pad dry cycles.

Evaluation of Ultrasonically ZnO Loading Effect on Photocatalytic Self-Cleaning, UV Protection and Antibacterial Activity of Plasma/Citric Acid-Activated Cotton Fabric

“…In the pre-coating citric acid treatment, the cotton fabric was functionalized with 0.5% dilute solution of citric acid in order to increase the adhesion of ZnO particles. Equations ( 1) and (2) show that when the cotton fibers and citric acid are placed in deionized water, both become ionized. In processing reactions, the hydroxyl groups (OH) on cotton are attached with the carboxylic groups of acid using the following Equation (3) [19].…”

“…The garment sector contributes to 80% of the total exports of the country. In the textile processing industry, a number of physical and chemical processes are carried out for the finishing of fabrics [2,3]. About 98% of textiles are dyed at early or later stages before hitting the market.…”

“…Atmospheric pressure plasma can remove non-cellular impurities from the surface of cotton through a physical etching process. Plasma treatment enhances hydrophilicity as well as sizing, dyeing, adhesion and surface roughness [2]. In plasma treatment, the surface of cotton fabric is incorporated with plasma-generated free radicals, which act as grafting or cross-linking agents.…”

Microwave Plasma Assisted Sol‐Gel Synthesis of TiO2 Photocatalyst for DC Plasma Jet Driven Degradation of Methylene Blue

“…The microwave synthesis is generally carried out in unconfined environment at atmospheric pressure where microwave irradiation accelerates the reaction by increasing the molecular vibrations and lowering the free energy of activation. [15] In a confined environment, the microwaves oscillate the omni present electrons in the environment. These electrons collide with gas atoms and molecules to produce ions, electrons and other reactive species.…”

Dielectric barrier plasma effect on surface functionality and coating properties of ultrasonically coated cotton with ZnO nanoparticles and Aloe vera extraction

“…Aloe vera belongs to the Aloeacea family (Kammoun et al 2011). The Aloe vera gel contains 99% water, and the rest of the solid content is composed of different compounds of medicinal benefits, including fat-soluble and water-soluble minerals, vitamins, polysaccharides, phenols, enzymes, organic acids, etc (Anwar et al 2021). Aloe vera has the medicinal properties, including purgative (Akao et al 1996), antimicrobial (Wang et al 1998), anticancer (Pecere et al 2000) and antioxidant (Lee et al 2001).…”