Search

Blending of plant-based cellulose and marine-derived chitosan in micro-level has potential to make fascinating materials. However, this task is frequently hindered by the poor solubility of the polysaccharides. Here, using a green alkali/urea solvent media together with a well-designed dissolving strategy, original cellulose pulp and chitosan power were dispersed into a homogeneous solution. Driven by the intermolecular hydrogen-bond interaction, cellulose and chitosan chains were facially self-assembled into a unique 3D alloy structure. Owing to the rich interface interactions, the tensile strength and breaking elongation of the alloy film increased by 69% and 260%, respectively, when compared to a pure chitosan film. Besides, the 3D alloy films with a pore diameter of 920–1435 nm exhibited an extremely high cell viability which was higher than 95%. Additionally, accelerated wound healing rate of 95.6% reached in the presence of the alloy film after two weeks using a full-thickness wound in a rat model. Unlabelled Image • Chitosan and cellulose were co-dissolved into one green alkali/urea solvent. • Polysaccharide chains were self-assembled into 3D porous alloy films. • Abundant interface interactions led to excellent physicochemical properties. • Biocompatibility and bioactivity of the alloy result in good wound healing. [ABSTRACT FROM AUTHOR]

In this study, hierarchically feather-mimetic structures formed of poly(m-phenylene isophthalamide) (PMIA) nanofibres were prepared by electrospinning and subsequent crystallisation for superwettability applications. X-ray diffraction measurementsand scanning electron microscopy show that a feather-mimetic structure of crystallised nanoflakes was formed following a hydrothermal treatment process. The nanoflakes formed a nanosized fine texture on top of a coarser-textured membrane, which greatly improved the membrane roughness and yielded a hierarchical topography. After fluorination, the membrane exhibited superamphiphobicity, with surface contact angles of 151° and 136° for water and hexadecane, respectively. The method provides new insight for the design and development of functional bionic membranes based on PMIA. [ABSTRACT FROM AUTHOR]

[Display omitted] • P/N/Si co-modified fabric was presented via covalent bond and electrostatic assembly. • Modified cotton fabric displayed excellent flame retardancy and self-extinguishing. • Improved washing durability was acquired with LOI of 27.1% after 50 LCs. • Smoke suppression performance was significantly improved. • Mechanical properties and moisture permeability were substantially retained. Flame retardant cotton fabric has attracted extensive attention and research with the increase of public safe awareness. However, it still remained a great challenge to balance the performances of high flame retardancy, durability, mechanical strength, as well as formaldehyde-free, comfort, green and feasible process. Herein, efficient, durable and breathable flame retardant cotton fabrics were fabricated through a one-pot approach based on a synergetic system combining phytic acid (PA) with polyethyleneimine (PEI) and 3-Glycidyloxypropyltrimethoxysilane (GPTMS). The modified cotton fabrics displayed high-efficiency fire resistance, self-extinguishing and excellent washing resistance due to the formation of surface hybrid network architectures from multiple covalent bonds (Si O C, C N, P O C) and electrostatic assembly. The limiting oxygen index (LOI) could retain at 27.1% after 50 laundering cycles (LCs). Moreover, the peak of heat release rate (PHRR), total heat release (THR) and total smoke release (TSP) declined by 85.89%, 52.72% and 47.22% compared with neat fabric, indicating boosted flame retardance and excellent smoke suppression ability. In addition, the proposed surface finishing process substantially retained the mechanical properties and moisture permeability, providing a simple and feasible approach for high-efficiency, durable and breathable flame retardant cotton fabric. [ABSTRACT FROM AUTHOR]

[Display omitted] • L-cysteine is first introduced into cotton fabric facilely using its hydrochloride. • Two antimicrobics are efficiently loaded and their synergistic effects are studied. • The integration of TA can significantly improve antibacterial activity of Ag NPs. • The presence of Ag NPs evidently makes cytotoxicity of tannic acid negligible. In this paper, L-cysteine (Cys) is firstly bonded to the surface of cotton non-woven (CO) fabric as esterification. In this way, Ag+ and tannic acid (TA) are adsorbed onto the modified fabric via complexation and hydrogen bond interaction. After a sustainable one-step redox reaction, a Cys modified CO fabric decorated with Ag NPs and TA (CO-Cys-Ag-TA) is prepared. Because of the stabilizing effect of Cys and TA, the synthesized Ag NPs with a mean size of 88.9 nm are uniformly distributed on the modified fabric surface. Through the comparative test, it has been revealed that the antibacterial activity of Ag NPs is improved after loading TA, and the loading of Ag NPs significantly reduces the cytotoxicity of TA. In this context, the bacteriostatic reduction rate of CO-Cys-Ag-TA against S. aureus and E. coli is close to 100%, and its antibacterial activities are greater than 98.5% after 50 washing cycles. Meanwhile, its cell viability value reaches up to 88.0% with the presence of 0.1 mg/mL to 0.8 mg/mL CO-Cys-Ag-TA. [ABSTRACT FROM AUTHOR]

Abstract: Cuprous oxide (Cu2O) nanocrystals have been successfully synthesized using copper acetate as precursors via a polyol process. The as-synthesized products were easily deposited on the surface of carbon nanofibres (CNFs) and then were characterized through XRD, FESEM, TEM and FTIR, etc. The photocatalytic performance of these composite films was evaluated using methyl orange as a model organic compound under visible light irradiation. Results showed that the shape of Cu2O nanparticles could be changed from irregular nanoparticle to cubic, flower-like particle assembled by Cu2O nanocubes with the change of the reaction conditions. All of these Cu2O/CNFs composite films showed the satisfied photocatalytic activity to methyl orange even after 3 cycles of degradation experiment due to the protectable function of carbon fibre films to the Cu2O nanocrystals. The Cu2O/CNFs composite films may offer a feasible method for the potential application of Cu2O nanocrystals in the treatment of organic contamination. [Copyright &y& Elsevier]

Abstract: Bombyx mori silk fibroin is of practical interest for its excellent intrinsic properties utilizable in the biotechnological and biomedical fields. Here, the silk fibroin films were pretreated with different methods and then used as the template for the hydroxyapatite (HA) crystal growth. To study the effect of silk films’ surface structure on the protein biomineralization, the films were immersed into 1.5 times simulated body fluid (1.5×SBF) to induce the HA deposition at 37°C. The results showed that an anisotropic growth of HA crystals was observed on the different films as judging from XRD, TEM and HRTEM data. This was thought that the positions and density of carboxyl groups, Cno groups on the surface of SF films may be different, which play the key effect on HA crystal growth. [Copyright &y& Elsevier]

Abstract: The Bombyx mori silk fibroin films (SFFs) were modified by a Cecropin B (CB) antimicrobial peptide, (NH2)-NGIVKAGPAIAVLGEAAL-CONH2, using the carbodiimide chemistry method. In order to avoid the dissolution of films during the modification procedure, the SFFs were first treated with 60% (v/v) ethanol aqueous solution, resulting a structural transition from unstable silk I to silk II. The investigation of modification conditions showed that the surface-modified SFFs had the satisfied antimicrobial activity and durability when they were activated by EDC·HCl/NHS solution followed by a treatment in CB peptide/PBS buffer (pH 6.5 or 8) solution at ambient temperature for 2h. Moreover, the surface-modified SFFs showed the smaller contact angle due to the hydrophilic antimicrobial peptides coupled on the film surface, which is essential for the cell adhesion and proliferation. AFM results indicated that the surface roughness of SFFs was considerably increased after the modification by the peptides. The elemental composition analysis results also suggested that the peptides were tightly coupled to the surface of SFFs. This approach may provide a new option to engineer the surface-modified implanted materials preventing the biomaterial-centered infection (BCI). [Copyright &y& Elsevier]

• In-situ synthesis of cuprous oxide (Cu 2 O) on cotton and coating with nanocellulose, the Cu 2 O crystal structures was ideal octahedron and not easy to ditch. • COCO-5 exhibited high photocatalytic degradation of dyes, and the catalytic degradation process was monitored by comprehensive technical tests. • COCO-5 exhibited highly effective antibacterial properties against Staphylococcus aureus and Escherichia coli. • COCO-5 maintained high stability after multiple photocatalytic degradation of dyes or antibacterial tests, and the mechanical properties of this composite had not decreased. In this study, the cotton fabrics/cuprous oxide-nanocellulose (Cu 2 O-NC) flexible and recyclable composite material (COCO) with highly efficient photocatalytic degradation of dyes and antibacterial properties was fabricated. Using flexible cotton fabrics as substrates, Cu 2 O were in-situ synthesized to make Cu 2 O uniformly grew on cotton fibers and were wrapped with NC. The photocatalytic degradation ability of COCO-5 was verified by use methylene blue (MB), the degradation rate was as high as 98.32%. The mechanism of COCO-5 photocatalysis and the process of dye degradation were analyzed by using electron paramagnetic resonance (EPR) spectrum, transient photocurrent response (TPR) spectrum, Fourier transform infrared (FTIR) spectroscopy and ion chromatography (IC). This study analyzed the complete path from electron excitation to dye degradation to harmless small molecules. Qualitative and quantitative experiments demonstrate that COCO-5 has high antibacterial activity against S. aureus and E. coli , the highest antibacterial rate can reach 93.25%. Finally, the stability of COCO-5 was verified by recycling and mechanical performance tests. The textile-based Cu 2 O functionalized material has photocatalytic degradation and antibacterial properties, and the preparation process is simple and convenient for repeated use, so it has great potential in wastewater treatment containing dyes and bacteria. [ABSTRACT FROM AUTHOR]

Robust, metal-free, macroscopic 3D porous CN/CE hybrid photocatalyst was fabricated by the co-assembly of g-C 3 N 4 and cellulose substrate, in which such an interconnected porous network facilitates mass transport, strong adsorption and multireflection of incident light. Consequently, the CN/CE hybrid photocatalyst exhibited both an excellent adsorption capacity and improved photocatalytic activity toward methylene blue degradation with degradation rate of 99.8%. • Robust, metal-free, 3D porous g-C 3 N 4 /cellulose hybrid photocatalyst was fabricated. • Highly porous network facilitates mass transport, adsorption and light multireflection. • Syncretic interface between g-C 3 N 4 and cellulose increases photoelectrons transfer. • Methylene blue removal ratio over the CN/CE hybrid photocatalyst reaches up to 99.8%. • The CN/CE hybrid photocatalyst exhibits mechanical stability and high reusability. Robust, metal-free, macroscopic 3D porous g-C 3 N 4 /cellulose (CN/CE) hybrid photocatalyst was successfully fabricated by the co-assembly of g-C 3 N 4 and cellulose substrate. The morphology, structure, mechanical property, optical and electrochemical performances, and photocatalytic activity of the CN/CE were investigated in detail. The obtained CN/CE hybrid photocatalyst possessed homogeneous 3D interconnected network structure, excellent mechanical strength and considerable recyclability. Also, the CN/CE hybrid photocatalyst exhibited both an excellent adsorption capacity and improved photocatalytic activity toward methylene blue (MB) degradation with degradation rate of 99.8%, much higher than that of pure g-C 3 N 4 (54.2%). The enhanced photocatalytic performance of CN/CE derived from the synergistic effects of homogeneous 3D interconnected network structure and syncretic interfaces between g-C 3 N 4 and cellulose, facilitating mass transport, light absorption and reactant adsorption, as well as the transfer of the photogenerated electrons. Moreover, the CN/CE hybrid photocatalyst indicated a high reusability and stability without significant reduction in its efficiency with nearly 96% of MB degradation after four cycles. This work not only demonstrated the importance of homogeneous interconnected network structure to prepare highly effective photocatalyst, but also provided a new insight into the approach for design and utilization of stable and recyclable metal-free photocatalyst for visible light derived contaminant degradation. [ABSTRACT FROM AUTHOR]