The fabrication of nanocomposite thin films with TiO2 nanoparticles by the layer-by-layer deposition method for multifunctional cotton fabrics

Investigating the effect of workwear textile modification with nanometal-embedded PMMA polymer by a spray method on textile air permeability, bending stiffness and surface temperature induced by near-infrared

Objectives. This study aimed to optimize modification of cotton-polyester textiles of workwear in terms of air permeability (AP), bending stiffness (BS) and near-infrared (NIR) reflectance using nanometal-embedded polymethyl methacrylate (PMMA) polymer by a spray method. Methods. This experimental study was carried out to modify cotton-polyester textiles using nanoparticles of aluminum oxide (Al2O3), tin oxide (SnO) and zinc oxide (ZnO) embedded in PMMA polymer with different weight percentages by a spray method under 215-psi pressure. The surface temperature of the textiles induced by the NIR spectrum and their comfort in terms of AP and BS were measured according to Standard No. ASTM D737 and BS 3356, respectively. Results. Cotton (65%)-polyester (35%) textiles can be modified with a PMMA-based aluminum and zinc nanoparticle composite with equal weight percentage using a pressurized spray method with good durability. Also, most NIR reflection is in the textile coated with aluminum and ZnO nanoparticle composite in the PMMA base. Conclusions. It is recommended that this composite be used in future studies to impregnate the clothing textile of outdoor workers in hot and arid regions by a spray method under pressure and its effects be investigated on reducing heat stress in these workers.

Characterization and photocatalytic activity of TiO2 nanoparticles on cotton fabrics, for antibacterial masks

The in-situ impregnation of two commercial cotton fabrics (lab coat and Indiolino) with TiO₂ nanoparticles (TiO₂-NPs) was carried out. For this, two commercial cotton fabrics were dipped in titanium isopropoxide, titanium butoxide and titanium tetrachloride solutions to the TiO₂-NPs formation and in-situ TiO₂-NPs impregnation on the cotton fabric surface by the sonochemical, hydrothermal and solvothermal methods, respectively. The impregnated fabrics were characterized by ATR-FTIR, SEM–EDS, Raman, UV–Vis, DRS and tension tests. The results showed the successful formation and impregnation of TiO₂-NPs on both cotton fabrics. The leaching of TiO₂-NPs from cotton fabrics was negligible after several washing cycles. The self-cleaning properties and antibacterial activity of TiO₂-NPs functionalized cotton fabrics were assessed by photocatalytic and antibacterial tests. The photocatalytic activity was determined by the degradation of methylene blue dye under UV and solar irradiation. The materials showed good photoactivity, since MB was degraded up to 99% under solar and UV irradiations in 60 min. The bactericidal capacity of the TiO₂-NPs on fabrics, evaluated in-situ by SEM, showed that Indiolino presented the best antibacterial properties against Escherichia coli and Bacillus pumilus.

Effect of silylating agents on the superhydrophobic and self-cleaning properties of siloxane/polydimethylsiloxane nanocomposite coatings on cellulosic fabric filters for oil-water separation

A new facile approach for preparing two nonfluorinated hybrid organic-inorganic siloxane/polydimethylsiloxane nanocomposite coatings for cotton fabrics is presented using two distinct silylating agents. The first coated fabric was prepared predominantly via trimethylsilyl modification using hexamethyldisilazane (HMDS) while higher amounts of trimethoxy(octadecyl)silane (TMOS) further enhanced the superhydrophobicity of the second coating matrix. Unlike HMDS with substituted silyl (Me3Si) groups, TMOS consists of hydrolysable trimethoxy silyl ((MeO)3Si) chemical groups that allowed for the formation of nanosilica with Si-O-Si linkages needed to foster stable coatings. After characterization and testing, these coated fabrics demonstrated varying responses to harsh solvents and thermal conditions. Both sets of coated fabrics exhibited unique capacities for self-cleaning and oil-water separation as superhydrophobic filters due to (a) their low surface energy silylated hybrid polysiloxane chemical groups, (b) their highly reduced surface wettability and (c) nanopatterned surface morphologies. In this study, coated superhydrophobic cotton fabrics revealed a higher static aqueous contact angle of more than 150° and sliding hysteresis angle of less than 5°. Coated fabrics with 30 mg TMOS/10 mg HMDS (CMF3) and 30 mg HMDS/10 mg TMOS (CTF3) exhibited optimal superhydrophobicity. Both fabrics also retained percentage separation efficiencies over 90% for both chloroform-water and toluene-water mixtures. However, CTF3 displayed with a recorded separation efficiency less than 90° after five filtration cycles.

S, M. V, S. R. S, P. M, V. R, Valiyaveettil S. Larvicidal, super hydrophobic and antibacterial properties of herbal nanoparticles from Acalypha indica for biomedical applications

Herbal nanoparticles usingAcalypha indicaleaves are investigated and found to possess superior larvicidal, water repellent and antimicrobial properties for biomedical applications.

Antibacterial textiles functionalized by layer-by-layer assembly of polyelectrolytes and TiO2photocatalyst

Antibacterial photocatalytic textiles with high self-decontaminating activity under solar light againstE. colihave been prepared by sprayed layer-by-layer assembly of TiO₂and polyethylenimine or polyanionic poly(styrene sulfonate) polyelectrolyte.

TiO2 thin films prepared via adsorptive self-assembly for self-cleaning applications

Low-cost controllable solution-based processes for preparation of titanium oxide (TiO(2)) thin films are highly desirable, because of many important applications of this oxide in catalytic decomposition of volatile organic compounds, advanced oxidation processes for wastewater and bactericidal treatments, self-cleaning window glass for green intelligent buildings, dye-sensitized solar cells, solid-state semiconductor metal-oxide solar cells, self-cleaning glass for photovoltaic devices, and general heterogeneous photocatalysis for fine chemicals etc. In this work, we develop a solution-based adsorptive self-assembly approach to fabricate anatase TiO(2) thin films on different glass substrates such as simple plane glass and patterned glass at variable compositions (normal soda lime glass or solar-grade borofloat glass). By tuning the number of process cycles (i.e., adsorption-then-heating) of TiO(2) colloidal suspension, we could facilely prepare large-area TiO(2) films at a desired thickness and with uniform crystallite morphology. Moreover, our as-prepared nanostructured TiO(2) thin films on glass substrates do not cause deterioration in optical transmission of glass; instead, they improve optical performance of commercial solar cells over a wide range of incident angles of light. Our as-prepared anatase TiO(2) thin films also display superhydrophilicity and excellent photocatalytic activity for self-cleaning application. For example, our investigation of photocatalytic degradation of methyl orange indicates that these thin films are indeed highly effective, in comparison to other commercial TiO(2) thin films under identical testing conditions.

Multifunctional transparent ZnO nanorod films

Transparent ZnO nanorod (NR) films that exhibit extreme wetting states (either superhydrophilicity or superhydrophobicity through surface chemical modification), high transmittance, UV protection and antireflection have been prepared via the facile ammonia hydrothermal method. The periodic 1D ZnO NR arrays showed extreme wetting states as well as antireflection properties due to their unique surface structure and prevented the UVA region from penetrating the substrate due to the unique material property of ZnO. Because of the simple, time-efficient and low temperature preparation process, ZnO NR films with useful functionalities are promising for fabrication of highly light transmissive, antireflective, UV protective, antifogging and self-cleaning optical materials to be used for optical devices and photovoltaic energy devices.