Traditional wound dressings such as cotton gauze and bandages are adhesive and often painful to detach from wounded skin, leading to additional damage to the wound. It is essential to develop low-adherent wound dressings for relief of pain and trauma in the wound healing process. In this work, a new methodology based on surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) was employed to fabricate hybrid cotton–hydrogel dressings via direct polymerization of poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) hydrogel on the surface of cotton fibers. The chemical structure, hydrophilicity, peeling energy, stiffness, and cell adhesion behavior of the hybrid dressings were investigated to elucidate the relationship between their surface structure and properties. The resulting hybrid dressings exhibited good biocompatibility, excellent mechanical strength, and low adhesion, and provided a favorable environment to promote wound healing. These results suggest that low-adherent hybrid dressings can be obtained by grafting hydrogels, having great potential for use in wound care.

Two series of poly(ethylene glycol)-b-polylactide-b-poly(ε-caprolactone) (MPEG-PLA-PCL) triblock copolymers with similar end-blocks (MPEG and PCL) lengths but varying mid-block (PLA) lengths were prepared by ring-opening polymerization (ROP) method and characterized by 1H NMR and GPC. The influence of mid-block length of these obtained copolymers on their surface activity, aggregation behavior, and emulsifying properties was investigated. When short PLA chain was inserted into the MPEG-PCL diblock copolymers, the formed triblock copolymers offer the advantage over the corresponding diblock copolymers. They allow higher solubility, faster interfacial adsorption, tighter micelle molecular packing, slightly larger micelle size, and higher emulsifying volume. When PLA chain was long, however, the triblock copolymers exhibited different properties due to the hydrophobicity of the chain. PLA chain length does not significantly affect the equilibrium surface tension. The findings based on this study not only demonstrate the important role of an inserted block with intermediate hydrophobicity on the physicochemical and emulsifying properties of block copolymers but also emphasize the impact of the chain length on these properties.

Cotton fabrics with sophisticated surface-specific properties were obtained by grafting poly(tert-butyl acrylate) (PtBA), poly(acrylic acid) (PAA), poly(oligo(ethylene oxide) monomethyl ether methacrylate) (POEOMA), poly(N,Ndimethylaminoethyl methacrylate) (PDMAEMA) and quaternized PDMAEMA (QPDMAEMA) bushes on cotton surfaces using surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) of three rather different monomers in a water-ethanol solvent. Due to the different physical properties and chemical composition of grafted polymers, the properties of such obtained cotton fabrics can be tailored including mechanical properties from enhanced tensile strength to increased breaking elongation, hydrophilic/hydrophobic characteristics from superhydrophilic to hydrophobic, varied water absorption abilities, different dye adsorption capabilities and charge properties. This work presents a high potential surface modification route towards functional textiles which are expected to play an important role in the future applications.

The fading of the triazinylstilbene fluorescent brighteners (TFBs) on cotton fabric under the conditions of exposure to sunlight and human sweat may reduce the visual quality and added value of the garment and also produce many toxic substances, which could threaten human health due to direct contact with skin. In order to investigate the light-fastness and perspiration stability of TFBs on cotton fabrics, three environmental factors of affecting the photo-fading of TFBs, i.e., ultraviolet irradiation, wet condition, and atmospheric constituents, were discussed according to AATCC standard. The results indicated that the effect of ultraviolet irradiation was more significant than its visible counterpart on the light and perspiration stability of TFBs on cotton fabrics. The light stability of TFBs was susceptible to the wet environment, and the presence of moisture accelerated the rate of photo-fading of TFBs. Furthermore, the study on the contribution of atmospheric constituents disclosed that the oxygen in the air together with the moisture of perspiration would make the synergistic effect on the fading of TFBs.

The anisotropic surface properties of macroscopic single crystals of C.I. Disperse Yellow 114 have been investigated. The changing contact angles between the facets of the crystal and water by drop contact angle measurements are associated with chemical heterogeneities present on the surfaces. The surface free energy on four indexed crystal facets, calculated by using Wu's method, indicated the dispersive components of the surface energies for the different crystal facets are close to each other, while its polar components are quite distinct. The anisotropic nature of the physical properties of the dye crystals is attributed to the functional groups and their densities on the individual crystal surfaces. Moreover, the surface hydrophobicity of compressed discs of milled crystalline dye powder was increased in comparison to that of crystal facets to such an extent that it is very difficult to predict the crystal surface properties from the compressed discs.Graphical abstractHighlights► The anisotropicity of a macroscopic single dye crystal has been revealed. ► The diverse wettability of crystal facets is attributed to chemical heterogeneities. ► It is different to predict the crystal surface properties from the compressed disc samples.

•Stilbene, 1,4-distyrylbenzene and 4,4′-distyrylbiphenyl were synthesized in liquid–liquid and solid–liquid PTC systems.•HWE reaction under PTC conditions showed high activity and geometric selectivity at relatively low temperatures.•The basicity of the available OH‾ had a significant influence on the activity and mechanism of HWE reaction in PTC system.•The region where the Cannizzaro intermediate was generated in the side reaction was varied with the reactivity of aldehyde.•The third phase and the reusability of the aqueous phase enhanced convenience and operability of PTC system.Stilbenes, 1,4-distyrylbenzenes and 4,4′-distyrylbiphenyls were synthesized via Horner–Wadsworth–Emmons (HWE) reaction in liquid–liquid (LL) and solid–liquid (SL) phase transfer catalysis (PTC) systems. The effect of the side reaction, reactants and the third phase on the activity of HWE reaction were investigated. For aldehydes bearing electron-donating substitute, the yields were more than 90% and the products were all (E)-isomers in both PTC systems. The SL-PTC system was milder than LL-PTC system for HWE reaction due to the different mechanisms. The side reaction of aldehyde was similar to Cannizzaro reaction, whereas the molar ratio of benzoic acid to benzyl alcohol as the products was not 1:1. The limited third phase was discovered to exist in LL-PTC system. In SL-PTC system, the third phase could increase substantially the reaction rate. Moreover, the aqueous phase in LL-PTC system could be reused four times without sacrifice of the yield and reaction rate.

A series of BiVO4/bentonite catalysts calcined at different temperatures were prepared by the solution combustion method and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Brunauer–Emmett–Teller (BET) specific surface area and ultraviolet–visible diffuse reflectance (UV–vis DRS) spectra. The results of BET analysis showed that BET specific surface area of BiVO4/bentonite crystallite decreased with increasing calcination temperature. The results of XRD, FE-SEM and UV–vis DRS analysis indicated that BiVO4 on bentonite calcined at 300 °C was in a monoclinic structure with a diameter of around 30 nm, as well as strong absorbance in a region of 350–500 nm. The photocatalytic activities of as-prepared catalysts were discussed by the degradation of C.I. Reactive Blue 19 (RB19) under simulated solar irradiation. It was found that the catalyst could be separated from aqueous suspensions by sedimentation after reaction, and maintained almost the same activity after being used five times.

A novel two-step process was developed to synthesize and deposit SiO2/TiO2 multilayer films onto the cotton fibers. In the first step, SiO2 particles on cotton fiber surface were synthesized via tetraethoxysilane hydrolysis in the presence of cotton fibers, in order to protect the fibers against photo-catalytic decomposition by TiO2 nanoparticles. In the second step, the growth of TiO2 nanoparticles into the modified cotton fiber surface was carried out via a sol–gel method at the temperature as low as 100 °C. The as-obtained SiO2/TiO2 multilayer films coated on cotton fibers were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, atomic force microscopy and X-ray diffraction, respectively.Highlights► We introduce a two-step method for coating SiO2/TiO2 films on the cotton fibers. ► The as-grown multilayer films are uniform taking root on the fiber surfaces. ► The innovation allows obtaining SiO2/TiO2 films on fibers in an easy and cheap way.

This study is focused on understanding the relationship between the molecular structure of a series of dye–polyether derivatives and its dispersing ability for parent disperse dye. The effects of dye–polyether derivatives including anchoring groups and polyether chains on the aggregation at the air/solution interface, adsorption behavior and dispersion stability for dye dispersions were investigated systematically to elucidate the governing stabilization mechanism. By comparing with their polyether monoamines counterparts, it was found that the introduction of dye molecule into polyether monoamines increased their aggregation tendency at the air/solution interface and the adsorbed amount on the dye particles surface. The adsorption behavior of dye–polyether derivatives can be described by scaling laws, consisting with the predicted brush-like conformation. Dyes dispersed with dye–polyether derivatives are stable while dispersions containing polyether monoamines present low stability. The result can be explained by particle interaction potential curves together with dynamic considerations. The copolymers in this study effluences the dye dispersion stability through both molecular weight and hydrophobicity. The enhanced stability of dye–polyether derivatives can be attributed to the increased adlayer thickness and polyether chain density.Graphical abstractThe introduction of dye molecule into polyether monoamines increased the adsorbed layer thickness and adsorption energy.Highlights► Disperse dye molecule was introduced to polyether monoamines and used as dispersants. ► The solution characterization and adsorption isotherm of copolymers were studied. ► The introduction of dye molecule doubled the saturation adsorbed amount. ► The introduction increased the adlayer thickness by about 2 nm. ► Stabilization mechanism can be explained by thermodynamic and kinetic considerations.

Carboxymethyl chitosan (NOCC) with different molecular weight (Mw) and degree of substitution (DS) was synthesized under heterogeneous conditions. The synthesized NOCC was employed as builders in removing unfixed dyes from reactive cotton dyeings. The factors influencing wash-off effectiveness, including the achievable Mw and DS of NOCC and the initial pH value of washing liquor, were investigated. NOCC with the Mw of 25.0 kDa and the DS of approximately 1.0 has achieved the best wash-off effectiveness at the same wash-off conditions. The wash-off effectiveness of NOCC increases with the increase of pH values of washing liquor. The wash-off mechanism was also discussed by spectroscopic study. This study concludes that NOCC is a potential candidate for removing the unfixed reactive dyes on cotton fabrics.

Chitosan biguanidine hydrochloride was synthesized by reacting chitosan with dicyandiamide under microwave irradiation. The influence of reaction temperature, reaction solvent and microwave heating time was studied, and optimal conditions were identified. The representative microwave synthesized chitosan biguanidine hydrochloride was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction measurement, taking chitosan as a reference. The solubility pH for the chitosan biguanidine hydrochloride with different substitution degrees was monitored. The antimicrobial activities of chitosan biguanidine hydrochloride were measured by means of the minimal inhibition concentration (MIC). In vitro antimicrobial activity of guanidinylated chitosans with different substitution degrees were evaluated against staphylococcus aureus, bacillus subtilis, escherichia coli and pseudomonas aeruginosa. The results show that the microwave irradiation method can increase the reaction rate by twelve times over the conventional method. Chitosan biguanidine hydrochloride are effective of bacteriostasis, compared with chitosan, guanidinylated chitosan had much better antibacterial activity. The antibacterial activity of chitosan biguanidine hydrochloride derivative enhanced with increasing substitution degrees of guanidinylated chitosan.