Multifunctional PES fabrics modified with colloidal Ag and TiO2 nanoparticles

This study is aimed to highlight the possibility of engineering the multifunctional textile nanocomposite material based on the polyester (PES) fabric modified with colloidal Ag and TiO₂ nanoparticles (NPs). The effects of concentration of NPs as well as the order of Ag and TiO₂ NPs loading on antimicrobial, UV protective, and photocatalytic properties of PES fabrics were examined. The antimicrobial activity of differently modified PES fabrics was tested against Gram‐negative bacterium Escherichia coli, Gram‐positive bacterium Staphylococcus aureus, and fungus Candida albicans. The concentration of Ag colloid and the order of Ag and TiO₂ NPs loading considerably affected the antimicrobial efficiency of PES fabrics. The fabrics provided maximum UV protection upon surface modification with Ag and TiO₂ NPs. Ag NPs enhanced Ag NPs enhanced the photodegradation activity of TiO₂ NPs and total photodegradation of methylene blue was achieved after 24 hr of UV illumination. Copyright © 2010 John Wiley & Sons, Ltd.     

Antimicrobial Performance of Plasma Corona Modified Cotton Treated with Silver Nitrate

Cotton fabric was treated by corona plasma discharge at different powers and numbers of passages. The carboxyl group content was determined by Methylene Blue staining and titration. Then, the untreated and treated cotton fabrics were treated with silver nitrate, and laundering test was carried out. The inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis for silver and antibacterial tests were done. The surface bonding and morphology were studied by FTIR/ATR spectroscopy and scanning electron microscopy (SEM), respectively. The plasma corona discharge treatment of cotton fabric increases the content of carboxyl groups. An increase in the power of plasma treatment increases the content of carboxyl groups and adsorption of silver ions. As a result, the antibacterial effect is enhanced and becomes more stable after repeated laundering.     

Functionalization of cotton fabrics with corona/air RF plasma and colloidal TiO2 nanoparticles

This study discusses the possibility of using a corona discharge at atmospheric pressure and air RF plasma at low pressure for the cotton fibre activation prior to deposition of colloidal TiO₂ nanoparticles in order to enhance antibacterial, UV protective and self-cleaning properties. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of TiO₂ nanoparticles on the surface of cotton fibres. XPS elemental mapping indicated that TiO₂ nanoparticles were more evenly distributed across the surface of untreated and corona pre-treated cotton fabrics in comparison with RF plasma pre-treated fabric. Atomic absorption spectroscopy measurements revealed that the equivalent total content of TiO₂ in the cotton fabrics pre-treated by corona and RF plasma was 31% higher than in the fabric that did not undergo any treatment prior to loading of TiO₂ nanoparticles. In order to achieve maximum bacteria (Gram-negative bacteria Escherichia coli) reduction, untreated cotton fabric had to be loaded with colloidal TiO₂ nanoparticles twice, but only once following corona or RF plasma pre-treatment. Deposition of TiO₂ nanoparticles onto cotton fabrics provided maximum UV protective rating of 50+. Extraordinary photocatalytic activity of TiO₂ nanoparticles deposited onto cotton fabrics was proved by self-cleaning of blueberry juice stains and photodegradation of methylene blue in aqueous solution under UV illumination.     

Nanocomposite polyester fabrics with in situ generated silver nanoparticles using tamarind leaf extract reducing agent

Using tamarind leaf extract as a reducing agent and various concentrated aq?AgNO₃ solutions as source, the silver nanoparticles (AgNPs) were in situ generated in polyester fabrics. The nanocomposite polyester fabrics were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and antibacterial tests. The size of the generated AgNPs varied between 50 and 120?nm. The X-ray analysis indicated the generation of both AgNPs and AgO nanoparticles in the nanocomposite fabrics. The nanocomposite polyester fabrics exhibited excellent antibacterial activity against both the Gram negative and Gram positive bacteria and hence can be considered for making antibacterial textiles.     

Synthesis and characterization of antibacterial chromium iron oxide nanoparticle‐loaded activated carbon for ultrasound‐assisted wastewater treatment

The aim of this study was to evaluate the surface adsorption capacity of CrFeO₃ nanoparticle‐loaded activated carbon (CrFeO₃‐NPs–AC) for the removal of a cationic dye (methyl violet, MV). CrFeO₃‐NPs were hydrothermally synthesized and loaded on AC followed by characterization using X‐ray diffraction, field‐emission scanning electron microscopy and energy‐dispersive and Fourier transform infrared spectroscopies. The CrFeO₃‐NPs were tested for in vitro antibacterial activities against Gram‐positive (Staphylococcus aureus) and Gram‐negative (Pseudomonas aeruginosa) bacteria. Minimum inhibitory and minimum bactericidal concentrations of CrFeO₃‐NPs–AC were obtained to be 50 and 100 μg ml^?1, respectively, against S. aureus and 25 and 50 μg ml^?1 against P. aeruginosa. These results indicated the antibacterial properties of CrFeO₃‐NPs–AC. To investigate the adsorption process, several systematic experiments were designed by varying parameters such as adsorbent mass, pH, initial MV concentration and sonication time. The adsorption process was modelled and the optimal conditions were determined to be 0.013 g, 7.4, 15 mg l^?1 and 8 min for adsorbent mass, pH, MV concentration and sonication time, respectively. The real experimental data were found to be efficiently explained by response surface methodology and genetic algorithm model. Kinetic studies for MV adsorption showed rapid sorption dynamics described by a second‐order kinetic model, suggesting a chemisorption mechanism. Then, the experimental equilibrium data obtained at various concentrations of MV and adsorbent masses were fitted to conventional Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. Dye adsorption equilibrium data were fitted well to the Langmuir isotherm. From the Langmuir model, the maximum monolayer capacity was calculated to be 65.67 mg g^?1 at optimum adsorbent mass.     

Preparation and properties of silver nanocomposite fabrics with in situ-generated silver nano particles using red sanders powder extract as reducing agent

Nanocomposite cotton fabrics with in situ-generated silver nanoparticles (AgNPs) were prepared by using Pterocarpus santalinus (Red sanders) extract in water as a reducing agent. The formation of AgNPs was analyzed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy. The SEM analysis of nanocomposites showed the presence of spherical AgNPs with a size range of 71–90?nm. FTIR spectra showed the involvement of hydroxyl and methylene groups of cellulose matrix in reducing the silver salt into AgNPs in the presence of red sanders powder extract as reducing agent for the in situ generation of AgNPs. These nanocomposite fabrics exhibited good antibacterial activity against Gram positive and Gram negative bacteria.     

Green synthesis and characterization of monodispersed silver nanoparticles obtained using oak fruit bark extract and their antibacterial activity

Green synthesis of silver nanoparticles (Ag NPs) has been achieved using oak fruit bark extract as a reducing, capping and stabilizing agent. The biosynthesized Ag NPs were characterized using various techniques. UV–visible spectrum of prepared silver colloidal solution showed absorption maximum at 433 nm. X‐ray diffraction and transmission electron microscopy analysis revealed that Ag NPs have a face‐centred cubic structure being spherical in shape with an average particle size of 20–25 nm. The toxicity of the Ag NPs was tested on bacterial species such as Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli by comparison based on diameter of inhibition zone in disc diffusion tests and minimum inhibitory concentration and minimum bactericidal concentration of NPs dispersed in liquid cultures. The antimicrobial activity of Ag NPs was greater towards Gram‐positive bacteria (S. aureus and B. subtilis) compared to Gram‐negative bacteria as determined using standard Kirby–Bauer disc diffusion assay and serial dilution. Copyright © 2016 John Wiley & Sons, Ltd.     

Metallogel Template Fabrication of pH‐Responsive Copolymer Nanowires Loaded with Silver Nanoparticles and Their Photocatalytic Degradation of Methylene Blue

Poly(N,N′‐methylenebisacrylamide–4‐vinylpyridine) (P(MBA‐4VP)) nanowires loaded with silver nanoparticles (Ag NPs) have been fabricated by silver metallogel template copolymerization, and subsequently, silver ions are reduced instead of the template being removed. Ag NPs with a diameter of 5–15 nm were dispersed throughout the core of P(MBA‐4VP) nanowires. The size and distribution of the formed Ag NPs could be finely controlled by reduction time. The pH sensitivity of P(MBA‐4VP) nanowires offers the possibility of Ag NP release from the nanowires under acidic conditions. The photocatalytic performance of the P(MBA‐4VP) nanowires loaded with Ag NPs was evaluated for the degradation of methylene blue (MB) under UV light irradiation. Their rate of degradation is dependent on the content and size of the Ag NPs, as well as the pH values of the MB solution. Moreover, the P(MBA‐4VP) nanowires loaded with Ag NPs exhibited high photostability, and the photocatalytic efficiency reduced by only 1.81 % after being used three times.     

Antibacterial cotton fabric prepared by a “grafting to” strategy using a QAC copolymer

Quaternary ammonium compounds (QACs) have outstanding antimicrobial effect, but covalent immobilization of plentiful QAC onto cotton fiber surface to realize a durable function remains a challenge. Herein, a quaternary ammonium monomer, [2-(methacryloyloxy) ethyl] trimethylammonium chloride (DMC) was co-polymerized with methyl acrylate (MA) to prepare an antibacterial copolymer, poly(DMC-co-MA). To graft the copolymer with an improved grafting efficiency, cotton fabric was treated using carboxymethyl chitosan (CMC) to establish an amino-functionalized fiber surface first. This treatment allows the amidation reactions between the amino groups and the pendant ester groups in the poly(DMC-co-MA) to take place, achieving a durable anionic polymer coating onto the fiber surfaces with remarkably antibacterial effect. Characterization results indicated that when DMC/MA monomer ratio was 100:1, the resulting copolymer endows the modified cotton fabric with antibacterial capability that inactivates all Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Even after 50 laundering cycles, more than 98.0% of the antibacterial rate could still be retained. Moreover, the wearing comfort properties such as softness, water absorption and air permeability of the finishing cotton fabrics have been insignificantly changed by comparing to the untreated cotton fabric.

     

Application of anisotropic silver nanoparticles: multifunctionalization of wool fabric

Anisotropic silver nanoparticles (NPs) were successfully employed to color the wool fabrics in this study. The modified wool fabrics exhibited brilliant colors due to the localized surface plasmon resonance (LSPR) properties of silver NPs. The colors of wool fabrics altered with the morphologies of silver NPs. These modified wool fabrics were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicated that anisotropic silver NPs were effectively assembled on the surface of wool fibers when the solution pH and temperature was about 4 and 40°C, respectively. This assembling of silver NPs on the wool fibers was realized by the electrostatic interaction between wool fibers and silver NPs. This technique was also applied to gold NPs. The fabrics treated with anisotropic silver NPs showed high antibacterial activity against the bacteria of Escherichia coli. This study opens a new approach to color and functionalize conventional textile materials.     

Green synthesis of silver nanoparticles using Thymus kotschyanus extract and evaluation of their antioxidant,antibacterial and cytotoxic effects

Present study used ecofriendly, cost efficient and easy method for synthesis of silver nanoparticles (Ag NPs) at the room temperature by Thymus Kotschyanus extract as reducing and capping agent. Various analytical technique including UV–Vis absorption spectroscopy determined presence of Ag NPs in the solution, the functional groups of Thymus Kotschyanus extract in the reduction and capping process of Ag NPs are approved by FT‐IR, crystallinity with the fcc plane approved from the X‐ray diffraction (XRD) pattern, energy dispersive spectroscopy (EDS) determined existence of elements in the sample, surface morphology, diverse shapes and size of present Ag NPs were showed by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). Beginning and end destroy temperature of present silver nanoparticles were determined by thermal gravimetric spectroscopy (TGA). In addition, antibacterial, antioxidant and cytotoxicity properties of Ag NPs were studied. Agar disk and agar well diffusion are the methods to determined antibacterial properties of synthesized Ag NPs. Also MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were recognized by macro broth dilution assay. DPPH free radical scavenging assay was used for antioxidant property and compare to butylated hydroxytoluene (BHT) as standard antioxidant that showed high antioxidant activity more than BHT. Synthesized Ag NPs have great cell viability in a dose depended manner and demonstrate that this method for synthesis silver nanoparticles provided nontoxic. The average diameter of synthesized Ag NPs was about 50–60 nm.     

In Situ Photo Sonosynthesis of Organic/Inorganic Nanocomposites on Wool Fabric Introducing Multifunctional Properties

Here, a novel and efficient process is introduced for producing wool fabric with multifunctional features through facile in situ photosonochemical synthesis of organic/inorganic nanocomposites. The fabric was treated with titanium isopropoxide, silver nitrate and ammonia in a sonobath for 1 h at 75–80°C. The crystal phase of the sono‐treated samples was characterized by X‐ray diffraction. The uniform distribution of the nanocomposite on the fiber surface was proved by field emission scanning electron microscope, energy dispersive X‐ray and mapping patterns. Further, the composition of the nanocomposites was investigated by X‐ray photoelectron spectroscopy. The sono‐treated wool fabrics illustrated excellent photocatalytic activities toward discoloration of Methylene Blue under sunlight and UV‐A irradiation. Also the fabrics indicated reasonable antibacterial/antifungal activities against Staphylococcus aureus, Escherichia coli and Candida albicans. The tensile properties of the sono‐treated fabrics enhanced comparing to the untreated and even conventional stirrer‐treated fabrics. Moreover, a central composite design based on response surface methodology was used to study the influence of titanium isopropoxide and silver molar ratio on the prepared nanocomposites sonobath. Finally, the optimum molar ratio was reported for the best responses.     

Antimicrobial finishing of cotton textile based on water glass by sol–gel method

A low temperature and cost-effective process for antimicrobial finishing of cotton textiles has been developed by sol–gel method. The antimicrobial treatment was performed by treating cotton textile with silica sols from water glass and then with silver nitrate solution. The antimicrobial activity was determined by using E. coli as a model for Gram-negative bacteria. The results showed that the treated textile has an excellent antimicrobial effect and laundering durability. SEM analysis showed coarse surface morphological change on the water glass treated cotton textile. The residual concentration of silver ion on fabrics was informed by ICP-MS. XPS results indicated that two different states of silver were present on the surface of the antimicrobial textile.     

N‐Phenyl‐substituted carbene precursors and their silver complexes: synthesis,characterization and antimicrobial activities

A series of unsymmetrically substituted N‐heterocyclic carbene (NHC) precursors ( 1a , 1b , 1c , 1d , 1e ) were synthesized from the reaction of N‐phenylbenzimidazole with various alkyl halides. These compounds were used to synthesize NHC–silver(I) complexes ( 2a , 2b , 2c , 2d , 2e ). The five new 1‐phenyl‐3‐alkylbenzimidazolium salts ( 1a , 1b , 1c , 1d , 1e ) and their NHC–silver complexes ( 2a , 2b , 2c , 2d , 2e ) were characterized by the ¹H NMR, ¹³C NMR and FT‐IR spectroscopic methods and elemental analysis techniques. Also, the two NHC–silver complexes 2b and 2c were characterized by single‐crystal X‐ray crystallography, which confirmed the linear C―Ag―Cl arrangements. The antibacterial activities of the NHC precursor and NHC–silver complexes were tested against three Gram‐positive bacterial strains (Bacillus subtilis, Listeria monocytogenes and Staphylococcus aureus) and three Gram‐negative bacterial strains (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) using the microdilution broth method. The NHC–silver complexes showed higher antibacterial activity than the NHC precursors. In addition, silver complexes 2a , 2b , 2c , 2d showed high antibacterial activity against the Gram‐positive bacteria L. monocytogenes and S. aureus compared to the standard, tetracycline. Copyright © 2014 John Wiley & Sons, Ltd.     

A One‐Step Process for the Antimicrobial Finishing of Textiles with Crystalline TiO2 Nanoparticles

Titanium oxide (TiO₂) nanoparticles (NPs) in their two forms, anatase and rutile, were synthesized and deposited onto the surface of cotton fabrics by using ultrasonic irradiation. The structure and morphology of the nanoparticles were analyzed by using characterization methods such as XRD, TEM, STEM, and EDS. The antimicrobial activities of the TiO₂–cotton composites were tested against Escherichia coli (Gram‐negative) and Staphylococcus aureus (Gram‐positive) strains, as well as against Candida albicans. Significant antimicrobial effect was observed, mainly against Staphylococcus aureus. In addition, the combination of visible light and TiO₂ NPs showed enhanced antimicrobial activity.     

The preparation and characterization of silver‐loading cellulose acetate hollow fiber membrane for water treatment

Silver‐loading asymmetric cellulose acetate (CA) hollow fiber membrane was spun via the dry jet‐wet spinning technique. The spinning solution was prepared by dissolving AgNO₃ and CA in N,N‐dimethylformamide (DMF). The silver ions were reduced in the spinning dope into silver nano‐particles. The morphology of the resulting hollow fibers was examined using a scanning electron microscope and the silver content in the fiber was measured using an inductively coupled plasma atomic emission spectrometer. The antibacterial activities were evaluated. These hollow fibers had a sponge‐like structure and dense inner and outer surfaces. At a 50 k magnification, the pore on the skin layer was not observable, while the nodule size was smaller than 10 nm. The residual silver content of as‐spun hollow fiber was about 60% of the original silver added in the polymer solution. After immersing in water bath for 180 days, the silver content in the bulk of the hollow fibers decreased to 60% and the silver content on the surface reduced to 10%, yet still showed antibacterial activity against Escherichia coli and Staphylococcus aureus. After permeating with water for 5 days, the silver content in the hollow fibers decreased, and did not show antibacterial activity against E. coli and S. aureus. Thus, silver content must be periodically replenished after permeation. The proper range of AgNO₃ in the spinning solution for CA hollow fiber should be about 100–1000 ppm. Copyright © 2005 John Wiley & Sons, Ltd.     

Preparation of chitosan functionalized end‐capped Ag‐NPs and composited with Fe3O4‐NPs: Controlled release to pH‐responsive delivery of progesterone and antibacterial activity against pseudomonas aeruginosa (PAO‐1)

In this work, functionalized chitosan end‐capped Ag nanoparticles (NPs) and composited with Fe₃O₄‐NPs was prepared as pH‐responsive controlled release carrier for gastric‐specific drug delivery. The structure of prepared material was characterized by FE‐SEM, XRD, EDS and FT‐IR analysis. The loading behavior of the progesterone onto this novel material was studied in aqueous medium at 25°C and their release was followed spectrophotometrically at 37°C in seven different buffer solutions (pH 1.2, 2.2, 3.2, 4.2, 5.2, 6.2 and 7.2) to simulate intestine and gastric media which experimental results reveal more release rate in pH 1.2 (gastric medium) with respect to other buffers. This observation is attributed to dependency of the CS‐IMBDO‐Ag‐Fe₃O₄‐NPs and progesterone structure with buffer pH that candidate this new material as prospective pH‐sensitive carrier for gastric‐targeted drug delivery. On the other hand, the antibacterial properties of this material against gram‐negative bacterium pseudomonas aeruginosa (PAO‐1) in agar plates was studied and accordingly based on broth micro dilution the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) with respect to standard CLSI in different concentrations of CS‐IMBDO‐Ag‐Fe₃O₄‐NPs was calculated. The results reveal that MIC and MBC values are 50 and 1250 μg/mL, respectively. In addition, extracts of Portulaca oleracea leaves was prepared and its antibacterial activity in single and binary system with CS‐IMBDO‐Ag‐Fe₃O₄‐NPs as synergies effect against PAO‐1 was tested and results shown that these materials have significant synergistic effect for each other.     

Synthesis and antibacterial activity of surface‐coated catechol‐conjugated polymer with silver nanoparticles on versatile substrate

In the present study, 2‐chloro‐3′,4′‐dihydroxyacetophenone (CCDP), a catechol derivative, was quaternized with poly(propylene oxide)‐g‐poly(dimethylaminoethyl methacrylate) (PPO‐g‐PDMA, PgP) to prepare surface coatings for various substrates. The surfaces of noble metals, oxides, and synthetic polymers were coated by immersion in an aqueous solution of CCDP quaternized with PgP (C‐PgP). The catechol functional groups that remained on the surface were used for deposition of Ag nanoparticles (AgNPs) on the coated surface, to provide a water‐resistant antibacterial polymer with long‐term antimicrobial activity. X‐ray photoelectron spectroscopy confirmed deposition of C‐PgP and AgNPs on the surface coated with the antibacterial polymer. Surface‐immobilized C‐PgP/AgNPs showed outstanding antibacterial activities against Staphylococcus aureus, a Gram‐positive bacterium, and Escherichia coli, a Gram‐negative bacterium. C‐PgP/AgNPs can be applied to a variety of substrates and can therefore be used as antibacterial materials in various fields. Copyright © 2016 John Wiley & Sons, Ltd.     

Novel properties of PES fabrics modified by corona discharge and colloidal TiO2 nanoparticles

The objective of this study was to highlight the potential application of the corona discharge at atmospheric pressure for the surface activation of polyester (PES) fabrics in order to improve the binding efficiency of colloidal TiO₂ nanoparticles. The obtained nanocomposite textile materials provide desirable level of UV protection, self‐cleaning properties, and photodegradation activity. The measured UV protection factor (UPF) of fabrics corresponds to UPF rating of 50+, designating the maximum UV protection. Additionally, the total photodegradation of methylene blue in aqueous solution was achieved after 24 hr of UV illumination and this capability was preserved and even improved after four repeated cycles. The results showed that the corona treated PES fabrics loaded with TiO₂ nanoparticles had considerably enhanced the overall efficiency compared to PES fabrics loaded only with TiO₂ nanoparticles. Copyright © 2009 John Wiley & Sons, Ltd.     

In situ Synthesis of Oil Based Polymer Composites Containing Silver Nanoparticles

Using electron transfer reaction and free radical polymerization processes a series of triglyceride oil based polymer‐silver nanocomposites were successfully prepared. The whole process was divided into two simultaneous stages; (i) copolymerization of macromonomers obtained from partial glycerides with styrene and (ii) the reduction of silver nitrate to metallic silver nano particles with radicals stemming from the thermolysis of 2,2′‐azoisobutyronitrile (AIBN). Nanocomposites were characterized by TEM and TGA. The obtained polymer nanocomposite was also examined in view of antibacterial effect against Gram‐positive, Gram‐negative, and Spore forming bacteria. It was demonstrated that nanocomposite samples exhibited an antibacterial effect against these bacteria. Film properties of the samples as potential coating material were also studied. Nanocomposite samples showed better film properties than that of the polymer without silver nanoparticles.