Silver‐containing sol–gel coatings on textiles: antimicrobial effect as a function of curing treatment

Textiles coated with inorganic SiO₂ layers containing silver nanoparticles were prepared using the sol–gel process. The formation of silver particles was investigated as a function of curing treatment variables performed after the coating procedure. The formation of silver particles in nanometre scale was determined with transmission electron microscopy (TEM). The optical properties of coated textiles were investigated using UV/Vis‐spectroscopy under arrangement of diffuse reflectance conditions, and the release of silver from coated textiles was determined with ICP‐spectroscopy. Under the chosen conditions, the formation of embedded silver clusters requires a curing treatment at a minimum temperature of 150°C. The silver‐containing inorganic coatings inhibit the growth of fungi (Aspergillus niger) and bacteria (Bacillus subtilis and Pseudomonas putida) on the coated textiles. The antimicrobial effect depends more on the temperature used for curing treatment and less on the duration chosen for the treatment of textiles after coating. Conditions for application between 150°C and 180°C are commensurate with those used in commercial textile finishing, so the process presented here could be easily adapted to the production of textiles with antimicrobial effects.     

Superhydrophobic cotton fabrics prepared by one-step water-based sol–gel coating

A simple one-step superhydrophobic coating method for cotton fabrics based on a modified silica hydrosol is presented in this study. The modified silica hydrosol was prepared by the co-hydrolysis/co-condensation of methyl trimethoxy silane and a non-fluoro compound, hexadecyltrimethoxysilane, via water-based sol–gel reaction under alkaline condition in the presence of a surfactant. The as-obtained products were characterized by particle size analyzer, scanning electron microscopy, scanning probe microscopy, X-ray photoelectron spectroscopy, and thermal gravimetric analysis. Superhydrophobic cotton fabric with a water contact angle of 151.9° for a 5?μL water droplet and a water shedding angle of 13° for a 15?μL water droplet was successfully obtained.     

Antimicrobial films containing lysozyme for active packaging obtained by sol–gel technique

Antimicrobial packaging is a promising form of active packaging that refers to the incorporation of antimicrobial agents into packaging systems with the aim to extend the product shelf life maintaining its quality and safety. In our work an antimicrobial active packaging based on poly(ethylene terephthalate) (PET) was prepared by sol–gel route, incorporating as antimicrobial agent lysozyme with the aim to obtain packaging films with controlled release properties. The fine tuning of the sol concentration and viscosity as well as the dip-coating extraction rate, allowed to deposit on the external surface of the PET support uniform coatings with controllable thickness at the sub-micron scale. FTIR microspectroscopic and tapping mode-Atomic Force Microscopy (TM-AFM) measurements were used to characterize the prepared coatings.     

Zinc oxide sol-containing diallylmethyl alkyl quaternary ammonium salt synthesized by sol–gel process: characterization and properties

Zinc oxide sols-containing quaternary ammonium bromide compounds, including diallylmethyl dodecyl/tetradecyl/hexadecyl/octadecyl ammonium bromide, were synthesized from zinc acetate and quaternary ammonium bromide compounds via sol–gel process. Effects of alkyl chain length and double allyl of quaternary ammonium salts on the stability of the sols were investigated. The sols were characterized by X-ray diffraction. Morphologies of the sols were observed with transmission electron microscopy. The various zinc oxide sols were applied to cotton fabrics. Antibacterial activity, UV resistance, and mechanical properties of the treated fabrics were tested. It was verified that alkyl chain length and double allyl of quaternary ammonium salts had effects on the stability of the sols. Application results showed that UV resistance and antibacterial rate of the fabric finished by zinc oxide sols-containing quaternary ammonium salts first increased and then decreased with an increase in the alkyl chain length of quaternary ammonium salts. However, the sols had negative effects on breaking strength and elongation at break of the fabric.     

Facial preparation of superhydrophobic and superoleophilic textiles by depositing nano-SiO2 for oil–water separation

In this study, a facile one-step dip-coating approach was reported for the fabrication of superhydrophobic and superoleophilic cotton fabrics for oil–water separation. By depositing the hydrophobic nano-SiO₂ on the micro-scale cotton fabric surface, the combination of the nano-SiO₂ and the micro-roughness cotton fabric created a micro/nano-binary surface roughness and presents superhydrophobicity and superoleophilicity. SEM, EDS, and TGA result shows that the treated cotton fabric was completely covered by the nano-SiO₂ particles when the nano-SiO₂ particles was about only 3.6 wt% of the pristine cotton fabric. The separation efficiency of the fabricated superhydrophobic and superoleophilic fabric was calculated up to 98.3 wt%. The one-step production technique described here is realizable for industrial use, relatively mild processing conditions, and large-scale fabrication.     

A novel treatment for multifunctional finishing and reactive dyeing of polyamide‐6–cotton blend

A new approach to simultaneous functional finishing and reactive dyeing of polyamide‐6–cotton fabric (50/50) is developed. The extent of improvement in the functional and dyeing properties is determined by the UV‐absorber, UV‐Sun® CEL, concentration, type and concentration of the used reactive dye as well as the treatment sequence. The UV‐protection and the antibacterial properties, against S. aureus (G+ve) and E. coli (G?ve) bacteria, of the simultaneously finished and dyed fabric samples are maintained even after 15 washing cycles. After 15 washing cycles, the depth of shades and the fastness properties of the obtained dyeings are not seriously affected. The incorporation of the used UV‐absorber onto the blend fibres was also confirmed by SEM analysis.     

Surimi–alginate gels as affected by setting: a study based on mixture design and regression models

Interaction and setting effects on surimi–alginate gels were investigated by d-optional mixture design and analyzed by linear and nonlinear manual or stepwise regression models. Nonlinear model showed significant interactions of surimi–water on water retention ability (WRA) and failure shear stress, and surimi–alginate on whiteness of control (non-set) surimi–alginate gels. But no interaction was found on shear strain of control gels. In set gels, only WRA fitted nonlinear model with interaction terms for surimi–water and alginate–water. Setting increased the gel functionalities such as WRA, whiteness, and shear stress of surimi–alginate gels. The response trace plots showed that WRAs and failure shear stresses of both control and set gels of surimi–alginate were increased by alginate and surimi contents, but decreased by water. However, whiteness was increased by water and surimi contents, but decreased by alginate, while shear strain was increased by surimi content, but decreased by alginate and water.     

The potential of phenol–formaldehyde as plasticizing agent for moulding applications of wood veneer: two-dimensional and three-dimensional moulding

Two phenol–formaldehyde resols, namely a low and a medium molecular weight phenol–formaldehyde, were investigated for their applicability as plasticizers in moulding of European beech veneer (Fagus sylvatica L.). Therefore, beech veneers specimens were impregnated with both phenol–formaldehyde resol types in various concentrations. Subsequently, two-dimensional mouldability of the veneer was tested in a three-point-bending test along and perpendicular to the grain. Additionally, three-dimensional moulding of the phenol–formaldehyde impregnated veneer was tested throughout a modified Erichsen cupping test, where the veneer is pressed through a circular shaped coining die. The obtained results indicate a significantly improved mouldability of the treated beech veneers compared to untreated, water-saturated control specimens. Even at low phenol–formaldehyde concentrations plasticizing effects were detected in longitudinal direction and perpendicular to the grain. These findings are substantiated by results from three-dimensional moulding. Furthermore, the low molecular weight phenol–formaldehyde treated veneers displayed a higher mouldability than medium molecular weight phenol–formaldehyde specimens at similar phenol–formaldehyde concentration.     

SPME followed by GC–MS: a powerful technique for qualitative analysis of honey volatiles

Volatile compounds from 40 honey samples of different botanic origin were analyzed by SPME followed by GC–MS. In order to obtain complementary data for an overall characterization of honey aroma, two different SPME fiber coatings (polyacrylate and carboxen/polydimethylsiloxane) were employed. The use of both fibers with a single chromatographic column afforded the identification or characterization, based on GC retention and mass spectral data, of a total of 193 volatile components. A total of 166 honey volatiles were characterized (146 identified) from CAR/PDMS data, this fiber being the most appropriate for isolation of low molecular weight compounds. Polyacrylate fiber was better for extraction of polar semivolatiles, allowing to identify 120 compounds and to characterize 132. Besides typical nectar components such as limonene, linalool, etc., different compounds from fermentation (ethanol and 2,3-butanediol), processing (furan derivatives), hive treatment (thymol), etc. were detected. Although many volatiles were common to most honey samples analyzed, other seemed to be characteristic of certain honey types. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Encapsulation of food grade antioxidant in natural biopolymer by electrospinning technique: A physicochemical study based on zein–gallic acid system

Gallic acid was successfully incorporated into zein ultra-fine fibres at different loading amount (5%, 10% and 20%) in order to develop an encapsulating technology for functional ingredient delivery using electrospinning. The produced fibres exhibit diameters ranging from 327 to 387 nm. The physical and thermal properties of encapsulated gallic acid were determined by X-ray diffraction (XRD) and differential scanning calorimetry (DSC); and the interaction between gallic acid and zein was attested by attenuated total reflection-Fourier transform infrared (ATR-FTIR). Thermogravimetric analysis (TGA) demonstrated a different thermal stability of the fabricated complex before and after the gallic acid incorporation. Lastly, the 1,1′-diphenyl-2-picrylhydrazyl (DPPH) assay showed that the gallic acid had retained its antioxidant activity after incorporation in zein electrospun fibres. Overall, electrospinning technique had shown promising results as an efficient and effective method for the preparation of sub-micron structured encapsulated functional ingredient that may find uses in food industry.     

Application of stitch-bonded multi‐plies made by using the extended warp knitting process: reinforcements with symmetrical layer arrangement for concrete

With the development of the extended stitch‐bonding process, an important modification of the production process for stitch‐bonded fabrics was realized. Through the introduction of a lateral shift of the needle bar, the stitch‐bonding process is essentially being changed compared with the working method used before. This has made possible the manufacturing of optimally adjusted textile semi‐finished products for numerous applications in the field of composite material. One such application – the usage of stitch‐bonded fabrics as a textile reinforcement for concrete – is analyzed in this article. It was observed that promising possibilities for the use of the extended stitch‐bonding process result from overcoming the known restrictions during the production with conventional stitch‐bonding machines. A markedly improved quality of textile reinforcement is achieved through the new binding patterns and the free arrangement of the layers. The reinforcement shows a verifiable better bonding behavior than the conventional method. Therefore, it is guaranteed that there is no spalling on the concrete surface at service load, which is an important prerequisite for the practical use of textile‐reinforced concrete.     

Method Development for Sulfonylurea Herbicides Analysis in Rapeseed Oil Samples by HPLC–DAD: Comparison of Zirconium-Based Sorbents and EMR-Lipid for Clean-up of QuEChERS Extract

This study develops a simple, cost-effective and sensitive high-performance liquid chromatography with diode array detector (HPLC–DAD) method for the simultaneous determination of eight sulfonylurea herbicides (oxasulfuron, metsulfuron-methyl, triasulfuron, chlorsulfuron, amidosulfuron, mesosulfuron-methyl, bensulfuron-methyl and tritosulfuron) in rapeseed oil. Extraction of target analytes was performed using quick, easy, cheap, effective, rugged and safe-based procedure followed by solid-phase extraction (SPE) and dispersive solid-phase extraction (d-SPE) clean-up, and presents good performance for all of the analytes with recoveries in the range of 67–133% and relative standard deviations (RSD) less than 15%. No significant matrix interference was observed due to the application of effective zirconium dioxide-based sorbent (Z-Sep). Method LOQs for most of the investigated analytes were set at satisfactory low value of 20 ng g^?1 in food product. The procedure was evaluated in analyses of actual samples. The most important steps of the method optimization are presented. Novel EMR-Lipid clean-up solution for samples with high fat content was evaluated and compared to Z-Sep sorbent.     

A New Extraction Method for the Determination of Oxytocin in Milk by Enzyme Immune Assay or High-Performance Liquid Chromatography: Validation by Liquid Chromatography–Mass Spectrometry

There has been a controversy regarding the use of exogenous oxytocin (OT) in milking cattle which may have toxicological consequences during nonphysiological exposure. In the present study, a new sensitive extraction method for OT was developed followed by enzyme immune assay (EIA) or high-performance liquid chromatography (HPLC) analysis. The extraction of OT in milk involves two steps: (1) TCA precipitation of milk proteins and (2) solid-phase extraction (SPE) cleanup process. Without these steps, analysis of OT in milk was not possible. Utilizing EIA as a quantitative tool the limit of detection (LOD) and limit of quantitation (LOQ) were found to be 7.74 and 10.3 pg?ml^?1, precision in terms of intra- and interday coefficient of variation was below 13 % (%RSD, N?=?8), while percent recoveries were between 85 and 92 %. Utilizing UV-HPLC, the LOD, LOQ, precision, and recovery values were found to be 4.1 ng?ml^?1, 9.8 ng?ml^?1, 2–10 %, and 84–91 %, respectively. OT was found to be stable against adverse temperature (up to 100 °C) and pH (2 to 10) and simulated gastric fluid digestibility assay. Four milk samples collected from the market were analyzed, which showed that TCA precipitation and SPE steps are mandatory and the results were validated by LC-MS showing mass ion peak at 1 kD.     

Thermosonication of peach juice: investigation of PPO and POD activities,physicochemical and bioactive compounds changes,and development of FT-IR–based chemometric models for the evaluation of quality

In this research, the effect of thermosonication on peach juice was investigated. Enzyme inactivation increased with increasing power, temperature, and time. Enzymes were completely inactivated by thermosonication at 60 °C that was lower than the complete inactivation temperature (70 °C) of thermal treatment. Generally, as pH decreased, titratable acidity and °Brix increased by increasing temperature for each thermosonication treatment. The color of peach juice was preserved, and it became lighter. The bioactive components were protected with thermosonication. Fourier transform infrared (FT-IR) spectroscopy with chemometrics was used to evaluate polyphenol oxidase and peroxidase activity and quality attributes during thermosonication treatment. Moreover, the treatment methods were differentiated using principal component analysis, and models that correlated enzyme activity, quality attributes, and bioactive compounds with infrared spectra were constructed using partial least-squares. FT-IR with chemometrics can be used as a reliable method in peach juice quality determination during thermosonication.     

Designing W1/O/W2 double emulsions stabilized by protein–polysaccharide complexes for producing edible films: Rheological,mechanical and water vapour properties

Rheological properties and the droplet mean volume-surface diameter of water-in-oil-in-water double emulsions E_LMP–WPI and E_CMC–WPI, stabilized with low-methoxyl pectin (LMP)–whey protein isolate (WPI) or sodium carboxymethylcellulose (CMC)–WPI complexes were determined. E_LMP–WPI emulsions showed smaller droplet diameter (2.47 μm) than E_CMC–WPI emulsions (10.68 μm), and higher values of apparent viscosity, storage modulus and loss modulus. Microstructure and mechanical properties of the F_LMP–WPI and F_CMC–WPI films were affected by the type of the stabilizing biopolymer complex used in the formulation of the E_LMP–WPI and E_CMC–WPI double emulsions from which were prepared. The F_LMP–WPI films microstructure consisted of a biopolymer mainframe relatively compact, interrupted by small emulsion droplets. The F_CMC–WPI film mainframe had an open and oriented structure, in which relatively large emulsion droplets were packed. F_LMP–WPI films presented higher values of transparency, tensile strength and Young’s modulus, but lower elongation percentage and comparable water vapour permeability than F_LMP–WPI films.