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Laser irradiation is used for surface modification of polymers aiming to improve their properties for different applications. The wettability of a polymeric surface can significantly affect its performance for biological applications. In this paper, the interaction of high-energy KrF laser photons in the two above- and below-threshold regimes with polyethersulfone polymer is studied. The role of morphological and chemical changes of the irradiated polymer and their correlation in the modification of the wetting property of this polymer is investigated. The obtained results show that the morphological parameter of surface roughness is the dominant mechanism in the below-threshold regime, while in the above-threshold region, the competition between this parameter and the carbonization amount of the surface determines the final hydrophilic response.

We here report a facile one-step approach to construction of antifogging and frost-resisting coatings on flexible substrates from poly(vinyl alcohol) (PVA). Excellent antifogging and frost-resisting properties were observed, and are derived from the hydrophilicity and hygroscopicity of coatings. The coatings are highly transparent, and the average transmittance of coatings increases with increase of the concentration of PVA aqueous solution.

UV-vis absorption and emission studies on zinc and iron porphyrin complexes bearing H-bonding distal superstructures have been performed in two different organic solvents- tetrahydrofuran (THF) (coordinating) and dichloromethane (DCM) (non-coordinating). Quantum yields and lifetimes have been measured for these complexes which are in good agreement with the other reported metalloporphyrins. Binding affinities with anionic ligands such as N_3^-, CN^-, S^-2, F^- were monitored for these two complexes in aqueous media and the respective binding constant values were calculated. The Zn complex shows more selectivity towards cyanide while the Fe complex shows more selectivity towards azide.

Graphene oxide (GO) has attracted much attention as a derivative of graphene. In addition, it appears to have many unique physicochemical properties and has been investigated widely in many areas. Herein, we prepare GOs using flake graphite (FG), expandable graphite (EG) and microcrystalline graphite (MG) as graphite precursors by the modified Hummers method. According to the X-ray diffraction (XRD), Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, we characterize the component, the functional group, the chemical state of the element and the structural disorder of the obtained GOs to reveal their oxidation degree. Besides, we evaluate the hydrophilicity of the obtained GOs with the water contact angle, and observe their microstructures by transmission electron microscopy (TEM). We find that the GO prepared with EG has a higher-degree oxidation and better hydrophilicity, and it will be exfoliated easily and forms a monolayer or quasi-monolayer structure. Finally, based on the structural characteristic of graphite precursor, we build the intercalation and oxidation model to illuminate the phenomenon.

An excellent novel laminar and hierarchical polyethyleneimine cross-linked graphene oxide/titanium dioxide (GO–TiO₂–PEI) membrane was successfully prepared by vacuum filtration technology using polyethyleneimine (PEI) as the cross-linking agent and a GO–TiO₂ nanocomposite as the substrate. The resultant membrane (GO–TiO₂–PEI) displayed a favorable antifouling performance with bovine serum albumin (BSA) and showed good hydrophilicity and wettability, with a static water contact angle of 13.2^∘. The stability of the GO–TiO₂–PEI membrane in aqueous solution obviously improved with the cross-linking of PEI compared with that of the GO and GO–TiO₂ membranes. The GO–TiO₂–PEI membrane also exhibited a satisfactory water flux of 48.6L m${}^{-2}$ h${}^{-1}$ bar${}^{-1}$. The GO–TiO₂–PEI membrane exhibited a good performance for effectively separating different dyes including methylene blue (MB), rhodamine B (RB), methyl orange (MO), sunset yellow (SY), new coccine (NC) and amaranth. All the above results suggested that the GO–TiO₂–PEI membrane could be used as an excellent stable hydrophilic membrane for efficiently separating dyes from aqueous solution.

The application of graphene for some particular fields including biomedical engineering was hindered by its poor aqueous dispersivity and hydrophobic property. In this study, the strategy of the functionalization of graphene with hyperbranched polyglycerol (HPG) by a facile procedure was proposed. By the epoxy ring-opening hyperbranched polymerization of glycidol, graphene surface was grafted with HPG layer with rich hydroxyl groups. The content of polyglycerol on HPG functionalized graphene (HPG-G) was determined to be 55%. The results of fourier transform infrared (FTIR), X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS) and UV–Vis demonstrated that HPG was successfully grafted onto graphene sheets (GSs), and the aromatic and crystalline structure of graphene was maintained after HPG functionalization. The obtained HPG-G composites possess high hydrophilicity and can be dispersed well in water. Furthermore, no discernable precipitation was found in HPG-G aqueous solution even after three months of storage.

The need for antimicrobial textiles is increasing nowadays, due to the detrimental effects of micro-organisms on textiles as well as human hygiene. So it is essential to control or inhibit the growth of these organisms on textile fabrics which turns out to be undesirable for the wearer as well as the textile itself. The natural and ecofriendly, antimicrobial agents for textile applications are gaining interest in recent times. Eucalyptus oil, tulsi leaf, Aloe vera, neem leaf extracts, etc., can be used as a bioactive agent for finishing the textile materials. Neem is known for its environmental compatibility and is harmless against non-target materials, besides being skin friendly and non-toxic. This has significantly increased the use of bioactive agents obtained from neem products in the area of antimicrobial textiles. A large amount of biocides has to be applied on to the fabric to control effectively the microbial growth and sustain the durability of the finish. In the present study, hydrophilicity of the cotton fabrics was increased by DC air plasma and cellulase enzyme treatments to improve the uptake of azadirachtin content in the fabrics. The hydrophilicity of the treated fabrics was determined using dynamic wicking test. The physical and chemical modifications on the plasma and enzyme treated fabrics were analyzed using SEM and UATR- FTIR respectively. The fabrics treated with plasma and enzyme is found to exhibit increased hydrophilicity thereby increasing the uptake of neem leaf extract. Methanolic extract of neem leaf was prepared and applied as an antimicrobial finish for the treated cotton fabrics by pad-dry-cure method. The antibacterial and antifungal properties of neem leaf extract finished cotton fabrics were evaluated for its activity against: S.aureus, E.coli, Penicillum, Trichoderma using standard qualitative and quantitative test methods. The synergetic effect of the two treatments on the antimicrobial activity and wash durability of the cotton fabrics were investigated and the results are discussed.

In this paper, a detailed investigation on the effect of RF plasma treatment in improving the hydrophilicity of cotton fabric has been carried out. The hydrophilicity of plasma treated samples has been assessed and the process parameters have been optimized for maximum hydrophilicity. The fabric samples that exhibited maximum hydrophilicity have been subjected to chemical and ATR-FTIR analysis to study the reaction mechanism that has occurred during plasma treatment. SEM analysis has been carried out to understand the morphological changes that occurred during plasma treatment. The effect of plasma treatment on the mean pore diameter of the fabric matrix has been analyzed using dynamic wicking test and air permeability test. An attempt has been made to understand the role of plasma treatment in improving the antimicrobial efficacy of this fabric when treated with methanolic extract of neem leaves. FTIR analysis of the antimicrobial finish treated samples has been carried out to understand the improvement in efficacy and durability.