Synthesis of core-shell fluorinated acrylate copolymers and its application as finishing agent for textile

Core-shell fluorinated acrylate copolymers emulsion was thus synthesized via the core-shell emulsion polymerization with the fluorinated monomers and acrylic monomers as the main raw materials and its properties were studied. PFMA, the fluorinated acrylate monomers, was synthesized by the esterification of perfluorooctanoyl chloride (PFOC) and hydroxypropyl methacrylate (HPMA). Then the core-shell fluorinated acrylate copolymers emulsion with a poly(MMA/BA/St) core and a poly(PFMA/MMA/BA) shell was synthesized via a starved semi-continuous core-shell emulsion polymerization method by using KPS and sodium bicarbonate as the initiator/buffer system and SDS/Twain 80 as the commixture emulsifier. Lastly, the synthesized copolymers was applied as textile finishing agent for cotton textile. The results of FT-IR and NMR indicated that PFMA had been synthesized as expected and effectively combined in the emulsion copolymerization. The GPC, zeta potential, TEM and DSC showed that the particles had uniform spherical core-shell structure with a diameter of 65-150 nm, and the distribution and emulsion stability was satisfactory. As XPS, FESEM and AFM shown, a hydrophobic structure which was similar to the structure of the lotus leaf were formed and the surface hydrophobicity of the films can be improved. Based on the analysis of DSC, thermal stabilities of the films were enhanced with the increase of fluorine content. Besides, FESEM of textiles showed that the surface of treated textiles were smooth and the edges were clear and visible, indicating significant improvement of the performance on water and oil repellent.     

Synthesis of cationic core-shell fluorine-containing polyacrylate soap-free latex and its application on cotton substrate

Fluorinated polyacrylate latexes are preferably potential materials for use in the textile finishing due to their special surface property and especially economical, low-toxic characteristics compared to fluorinated polyacrylate solutions. A novel cationic fluorine-containing polyacrylate soap-free latex (CFMBD) with core-shell structure was accordingly developed by co-polymerizing dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and dimethylaminoethyl methacrylate (DM) using a cationic reactive emulsifier, maleic acid double ester-octadecyl poly(ethyleneoxy)₂₀ ether-ethylene trimethyl ammonium chloride (R303). Then CFMBD was utilized to treat the cotton fabric. Results showed that the as-prepared latex had due structure and its particles had uniform spherical core-shell structure with an average diameter of 125 nm. The core-shell CFMBD latex film thus had two T _g and its thermal property was improved due to the introduction of DFMA. CFMBD could form a smooth resin film on the treated fabric/fiber surface under FESEM observation. XPS analysis indicated the fluoroalkyl groups had the tendency to enrich at the film-air interface. Hydrophobicity of the CFMBD treated fabric was slightly superior to that of the fabric treated by general emulsion but their oleophobicity was identical. Contact angles of water and diiodomethane on the CFMBD treated fabric surface could attain 133.5 ° and 105.5 °, respectively. However, washing durability of the treated fabric by CFMBD showed improvement compared to the general emulsion. In addition, CFMBD didn’t influence whiteness of the treated fabric but would make it slightly stiff at high doses.     

Effect of CaCO3 contents on the properties of polyethylene nanocomposites sheets

Nanocomposites of high-density polyethylene/linear low-density polyethylene (HDPE/LLDPE) filled with untreated and surface treated nano-calcium carbonate (nCC) were prepared. The influence of isopropyl tri-(dioctylpyrophosphato) titanate (JN114) treatment of nCC on the morphology, mechanical, crystallization and flow properties of the nanocomposites were studied. The results of scanning electron microscopy (SEM) showed that JN114 treated nCC was better dispersion in the matrix than the untreated one. A fine dispersion of the treated nanoparticles in the nanocomposites was observed by transmission electron microscopy (TEM). The FTIR spectrum analysis revealed that the JN114 could change the surface properties of nCC, resulting in greater hydrophobicity of the surface and enhanced compatibility with nonpolar matrices. The tensile elastic modulus (E _c ) and Izod impact strength (SIC) of nanocomposites increased with the increasing of nCC content while tensile fracture strength (σ _b ) decreased. The JN114 treated nanocomposites had superior mechanical properties to those of the untreated ones. The compatibility of these nanocomposites was examined by DSC to estimate melting point (T _m ) and crystallization temperature (T _c ). Furthermore, the melt flow index (MFI) of the nanocomposite materials were measured. It was found that the MFI decreased with the addition of weight fraction of the nCC particles.     

Influence of the CF4 plasma treatments on the wettability of polypropylene fabrics

A plasma treatment using saturated CF₄ gas was employed to improve the resistance of polypropylene fabrics to water wetting. The fabrics were significantly fluorinated even within a short treatment time of 30 seconds. The result of contact angle measurement indicated that such highly hydrophobic surface was considerably durable even after 150 days of aging.     

Surface modification of HMPBO fibers by silane coupling agent of KH-560 treatment assisted by ultrasonic vibration

The surface modification of poly (p-phenylene-2,6-benzobisoxazole) (HMPBO) fibers by silane coupling agent of ??-aminopropyl triethoxy silane (KH-560) treatment assisted by ultrasonic vibration was investigated. The chemical composition and surface morphologies of the HMPBO fibers were analyzed and characterized by XPS, FTIR, TGA and SEM. The tensile properties of the HMPBO fibers were also studied. The results indicated that polar hydroxyl groups were successfully introduced on the HMPBO surface after the proposed treatment processes, and the surface roughness of HMPBO fibers was increased. Moreover, the treated HMPBO maintained relatively excellent tensile strength, and the single fiber pull-out strength of HMPBO was improved from 0.94 MPa to 1.07 MPa.     

Effect of thermal modification on the properties of narrow-leaved ash and chestnut

The concept of thermal modification has evolved from a challenging research program to commercial reality in several European countries in recent years. The aim of this study is to determine the change of various physical properties (oven-dry density, air-dry density, weight loss, swelling and anti-swelling efficiency (ASE)), compression strength parallel to grain, colour difference (ΔE), glossiness and surface roughness of narrow-leaved ash (Fraxinus angustifolia Vahl.) and chestnut (Castanea sativa Mill.) woods after heat treatment under different temperatures and durations. For this study two different temperatures (160 °C and 180 °C) and two different durations (2 h and 4 h) were considered. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber. Four main roughness parameters which are mean arithmetic deviation of profile (R_a), mean peak-to-valley height (R_z), root mean square roughness (R_q), and maximum roughness (R_y) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. The properties studied were significantly different (p = 0.05) at two temperatures and two durations of heat treatment. Based on the findings of this study, the results showed that oven-dry density, air-dry density, swelling, compression strength parallel to grain and surface roughness decreases with increasing heat treatment temperature and time.     

Effect of different fractions of zein on the mechanical and phase properties of zein films at nano-scale

The phase behavior of zein films has been investigated at nano-scale using atomic force microscopy (AFM) and compared to the phase behavior of the bulk using a thermal characterization technique. The local surface properties of the films were evaluated as a function of water activity using AFM. The glass transition temperature (T_g) of zein films decreased with increasing water activity. Adhesion forces measured by the AFM force curves increased with increasing water activity. Topography of zein and zein fractions were evaluated both qualitatively and quantitatively by the use of AFM and dedicated software to calculate the surface roughness. It has been found that processing technologies (solvent casting, drop deposition and spin casting) has influence on the surface structures of films. The films which were formed by the alpha zein rich fraction were found to have highest roughness values. Sectional surface profiles revealed that α-zein films have mean roughness (R_a) of 1.808 nm and root mean square roughness (RMS) of 2.239 nm while β-zein films have mean roughness (R_a) of 1.745 nm and root mean square roughness (RMS) of 3.623 nm. The discussions conducted on the differences/similarities in the observations were based on the hydrophobic/hydrophilic properties and interactions of these zein fractions.     

Enhanced surface property of HMPBO fibers by using γ-aminopropyl triethoxy silane

The silane coupling agent of γ-aminopropyl triethoxy silane combined with ultrasonic vibration was employed to modify the surface of high modulus poly (p-phenylene-2, 6-benzobisoxazole) (HMPBO) fibers. The results showed that polar hydroxyl groups were successfully introduced on the HMPBO surface. The contact angles on HMPBO fibers both for water (θ _water ) and for glycol (θ _glycol ) gradually were decreased, and the surface roughness of HMPBO fibers was also increased. Meanwhile, the single fiber pull-out strength of HMPBO was increased accordingly.     

Film morphology of supramolecule CPES/ASO and its performance on cotton substrates

The supramolecule CPES/ASO was self-assembled from carboxylated polyether-block-polydimethylsiloxane (CPES) and N-β-aminoethyl-γ-aminopropyl polysiloxane (ASO) in ethyl acetate solution. The film morphology and performance of CPES/ASO on cotton substrates were investigated by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray photoelectron microscope (XPS), and so on. The results indicated that a polysiloxane resin film was coated on the treated fiber surface and able to decrease the root mean square roughness (R _q ) of the treated fiber conspicuously. Morphology of higher peaks circled by many smaller peaks was observed on the film surface, which was partly similar to that of CPES/ASO on the silicon wafer. Besides, when the mass ratio of CPES to ASO was 2:1, the fabric treated by CPES/ASO showed the best softness and had a comfortable oily tactile.     

The effect of alkali pre-treatment on formation and adsorption of silver nanoparticles on cotton surface

This study is an attempt to investigate the feasibility of alkali pre-treatment to activate surface hydroxyl groups of cellulose fibers in order to enhance the deposition efficiency of silver nanoparticles (AgNPs) onto cotton fabrics. Cotton samples were pre-treated with various alkali solutions containing different earth metal hydroxides (LiOH, NaOH, and KOH). The as-prepared samples were then treated with aqueous silver nitrate followed by reduction treatment with aqueous ascorbic acid, which caused in situ formation of AgNPs on fiber surfaces. The surface structure of the fabrics was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) analysis, and colorimetric data. The amount of silver was measured by using inductively coupled plasma-optical emission spectrometer (ICP-OES). Antimicrobial activity was measured against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. It was established that alkali pre-treatment had a substantial effect on the formation and adsorption of AgNPs on the fibers. Alkali pre-treated samples were homogeneously coated by AgNPs with high surface coverage. Alkali type had significant effect not only on the amount of AgNPs on the surface but also on its size. High antibacterial activity against both Gram-positive and Gram-negative strains was also demonstrated, even after 10 cycles washing.     

Optimization of a monitoring system for the pine beauty moth, Panolis flammea (Denis & Schiffermüller), using sex attractants

The efficiency of traps baited with synthetic sex attractants, (Z)-9- and (Z)-11-tetradecenyl acetates, for Panolis flammea (Denis & Schiffermüller) (Lepidoptera: Noctuidae) was tested with respect to trap design, capacity, height, alignment, position and dose of lure. For optimum catches, traps should not be obstructed by vegetation, and can be placed most conveniently in forest rides. The most important features of trap design were a heavy surface coating of sticky retentive material and a large catching area. The efficiency of capture decreased rapidly when 40 or more moths were present on a sticky surface of area 380 cm². Numbers of moths caught increased regularly as the dose of lure increased from 1 μg to 5 mg. Males of Orthosia gothica (L.) (Lepidoptera: Noctuidae) were frequently caught in numbers similar to those of P. flammea in the same traps during the flight period of the latter insect. Increasing the relative quantity of the minor component, (Z)-11-tetradecenyl acetate, reduced catches of P. flammea, but not always those of O. gothica.     

One Step Thermochromic Pigment Printing and Ag NPs Antibacterial Functional Finishing of Cotton and Cotton/PET Fabrics

One step thermochromic pigment printing and antibacterial functionality of cotton (100 %) and cotton/polyester blend (50/50 %) were demonstrated in this study. The improvement in antimicrobial activity against G+ve (Bacillus cereus) and G-ve (E. coli), and pigment printability were achieved by inclusion of Ag-NPs (30 g/kg) into pigment printing paste followed by printing and microwave curing at 700 W for 5 min. Modes of interactions were proposed, and surface modification was also confirmed by SEM and EDX analysis that proved the presence of Ag-NPs in cotton and cotton/ polyester blended samples. The results indicated that the colour fastness to wash and rubbing was excellent, the surface roughness reduced, and exhibited good antibacterial activity against Bacillus cereus and E. coli bacteria.     

Wettability and roughness characteristics of modified wood boards using a hot-press

The aim of this study was to investigate the effect of the thermal modification process by hot-press on the wettability and surface roughness characteristics of the eucalyptus wood boards. The roughness measurements, average roughness (R_a), and maximum roughness (R_max) were taken both parallel and perpendicular to the grain using a fine stylus tracing technique. Contact angle measurements were obtained using a goniometer system connected to a digital camera and computer system. The results showed that surface roughness values of the modified wood boards using a hot-press significantly decreased with increasing press pressure and with decreasing temperature. The contact angle measurements indicated that the thermal modification had a significant influence on the surface wettability of the wood boards. Statistical analyses showed significant differences in the surface roughness and contact angle values of the wood boards following thermal modification. The results acquired in this work provide important information for future research and utilization of the thermally modified wood boards.     

Molecular and Chemical Analysis of the Lipopolysaccharide from Aeromonas hydrophila Strain AH-1 (Serotype O11)

A group of virulent Aeromonas hydrophila, A. sobria, and A. veronii biovar sobria strains isolated from humans and fish have been described; these strains classified to serotype O11 are serologically related by their lipopolysaccharide (LPS) O-antigen (O-polysaccharide), and the presence of an S-layer consisting of multiple copies of a crystalline surface array protein with a molecular weight of 52 kDa in the form of a crystalline surface array which lies peripheral to the cell wall. A. hydrophila strain AH-1 is one of them. We isolated the LPS from this strain and determined the structure of the O-polysaccharide, which was similar to that previously described for another strain of serotype O11. The genetics of the O11-antigen showed the genes (wb_O11 cluster) in two sections separated by genes involved in biosynthesis and assembly of the S-layer. The O11-antigen LPS is an example of an ABC-2-transporter-dependent pathway for O-antigen heteropolysaccharide (disaccharide) assembly. The genes involved in the biosynthesis of the LPS core (waa_O11 cluster) were also identified in three different chromosome regions being nearly identical to the ones described for A. hydrophila AH-3 (serotype O34). The genetic data and preliminary chemical analysis indicated that the LPS core for strain AH-1 is identical to the one for strain AH-3.     

Surface modification of polysulfones via one-pot ATRP and click chemistry: Zwitterionic graft complex and their hemocompatibility

Zwitterionic sulfobetaine groups were grafted onto polysulfone (PSU) membrane surface with 2-azidoethyl methacrylate and N,N-diethyl-N-propargyl-N-(3-sulfopropyl) ammonium (DEPAS) via surface-initiated Atom Transfer Radical Polymerization (ATRP) and “click” chemistry in a two-step process. The PSU membranes were fully characterized by attenuated total reflectance Fourier transform infrared spectra (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and static water contact angle (WCA) measurement. Results showed that zwitterionic monomers were efficiently grafted onto PSU surfaces. The water contact angle, bovine serum albumin (BSA) protein adsorption and platelet adhesion were obviously decreased after grafting zwitterionic sulfobetaine groups onto the membrane surface. These indicated that the zwitterionic sulfobetaine modified PSU membranes presented good biocompatibility. This study provides a new approach for surface modification of polysulfone with different functionalities.     

Synthesis of silver nanoparticles with sericin and functional finishing to cotton fabrics

This research presents a novel strategy to fabricate multi-functional cotton textiles. In this study, silver nanoparticles-sericin (Ag NPS-sericin) hybrid colloid has been prepared using sericin as reducing agent and dispersing agent. Cotton fabrics was oxidized selectively with sodium periodate (NaIO₄) to generate oxidized cotton fabrics, and which has then been finished using Ag NPS-sericin hybrid colloid prepared to obtain multi-functional cotton textiles. The finished cotton fabric not only possessed excellent antibacterial activity, but also it was modified functionally by sericin protein, which endowed antibacterial cotton fabrics relatively smooth surface and good wear ability. Fourier transform infrared spectrogram confirmed that sericin protein was grafted onto cellulose fibers. Ag NPs were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM) and X-ray powder diffraction (XRD). The results of SEM, X-ray photoelectron spectroscopy (XPS) and EDS confirmed that silver nanoparticles and sericin been loaded successfully on the surface of cotton fabrics. The antibacterial experiments showed bacterial reduction rates of S.aureus and E.coli were able to reach above 99 %. After washing 20 times, it showed still good antibacterial activity at over 95 % against S.aureus and E.coli.     

Characterization of the surface properties of cellulosic fibers in fibrous and ground forms by IGC and contact angle measurements

Surface properties of fibrous and ground cotton and linen were investigated by inverse gas chromatography (IGC) and the contact angle with different liquids was also measured on fabrics composed of both fibers. Results proved that dispersion component of surface tension (γ _s ^d ) determined by IGC depends not only on the surface energy, but also on several factors influencing the adsorbability of probe molecules on the cellulosic substrates. For cotton samples, the trapping of n-alkanes among waxy molecules in the outer layer of fibers can be presumed. This effect results in larger γ _s ^d for cotton fibers than for linen in spite of the higher wettability of the linen fabrics. Besides the surface energy and trapping effects, the grinding also influences the γ _s ^d values. Specific enthalpy of adsorption (ΔH _A ^ab ) of polar probes could be determined on all linen samples, but only on the ground cotton sample. Lewis acid-base character calculated for linen and ground cotton samples depends on the same effects as the γ _s ^d does. The similar ΔH _A ^ab values of chloroform (acidic) and THF (basic) measured on each of the samples support the conclusion that the surface character is amphoteric, which is also proved by the high ΔH _A ^ab values of the amphoteric ethyl acetate and acetone probes.     

Effects of ultrasound-assisted freezing on the water migration of dough and the structural characteristics of gluten components

The effects of ultrasound-assisted freezing on the freezing time and water migration of dough, and the structural characteristics of gluten components were investigated. The effects of ultrasound-assisted freezing in the whole immersion freezing process (UWF) on the freezing time were better than those of ultrasound-assisted freezing in the maximum ice crystal generation zone. The shortest freezing time was obtained at 80 W/L, and was 577 s shorter than that with traditional immersion freezing. The UWF treatment at 80 W/L significantly (p < 0.05) affected the absorption enthalpy, freezable water content and water migration of frozen dough. In UWF compared with traditional immersion freezing, the SH content of gluten, glutenin and gliadin was significantly (p < 0.05) higher, by 12.06%, 27.55% and 21.65%, respectively. The surface hydrophobicity of gluten, glutenin and gliadin in UWF treated samples significantly (p < 0.05) decreased, by 19.67%, 13.21% and 9.17%, respectively. The secondary structure of gluten components was also significantly changed by UWF. The network of gluten, the chain structure of glutenin and the gliadin particles were all changed by UWF treatment. These findings indicated that UWF is an effective method to improve the moisture distribution in dough and reduce the damage to protein molecular structure caused by freezing.     

Polymorphism of High MrGlutenin Subunits in Triticum tauschii: Characterisation by Chromatography and Electrophoretic Methods

A large collection of accessions of the wild wheat progenitor Triticum tauschii, the donor of the D genome of Triticum aestivum, was evaluated for the variability of high molecular weight (M_r) glutenin subunits by electrophoretic and chromatographic methods. A large range of allelic variation at theGlu-D^t1 locus was found in this collection and some novel subunits were observed in both x- and y-type glutenin subunits, including x- or y-type null forms. A few accessions showed three bands in the high M_rglutenin subunit region. However, only two subunits were observed when monomeric proteins were removed before SDS-PAGE analysis of polymeric proteins. The presence of monomeric proteins in this region is discussed. Characterisation of these subunits was also carried out by reversed phase-high performance liquid chromatography (RP-HPLC). Very different surface hydrophobicities were observed between x- and y-type subunits and in some cases it was possible to identify glutenin subunits with the same apparent molecular weight but different surface hydrophobicity. Differences in elution times that were detected when the same subunit was either reduced or reduced and alkylated were related to the number of cysteine residues present in each glutenin subunit. The newGlu-D^t1 glutenin subunits have the potential to enhance the genetic variability available for improving the quality of bread wheat (T. aestivum).     

Discriminating power of selected physical properties of seeds of various rapeseed (Brassica napus L.) cultivars

In this study, the seeds of open-pollinated winter rapeseed cultivars, hybrid winter rapeseed cultivars, open-pollinated spring rapeseed cultivars and hybrid spring rapeseed cultivars were investigated. The physical, optical, mechanical, geometric and image texture properties of rapeseeds were compared. Statistical models were developed based on the analyzed parameters to discriminate between seed groups. Most parameters effectively discriminated between cultivars of winter and spring rapeseed, including true density, porosity, L*, a*, b*, and spectral values at 400 nm, 470 nm, 500–530 nm, 560–620 nm, 640–650 nm and 690 nm. Four homogeneous groups were identified based on linear dimensions: F (surface area), S (width) and shape factors W₆ (circularity ratio), Rb (Blair-Bliss coefficient) and W₁₃ (roundness). No statistically significant differences in the mean values of hardness or area under the force-displacement graph were observed between seed groups. The model developed based on image texture variables from channel Y (luminance) was characterized by the highest discrimination accuracy of 82–87%. The experimental groups were classified with 89–92% accuracy in the model combining the best variables from each group of physical parameters. Total classification accuracy in neural networks reached 75% for a validation set comprising geometric properties and 91–92% for a validation set containing physical characteristics.