Dan Yu

Preparation of a reactive flame retardant and its finishing on cotton fabrics based on click chemistry

In this study, the non-halogenated organophosphorus flame retardant dimethyl-[1,3,5-(3,5-triacryloylhexahydro)triazinyl]-3-oxopropylphosphonate (DHTP) was synthesized and immobilized on cotton fabrics for a flame retardant finishing using click chemistry. The reaction and surface morphology were characterized by scanning electronic microscopy (SEM), energy dispersive spectrometer (EDS), and Fourier transform infrared spectroscopy (FTIR). Excellent flame retardancy was obtained by the limited oxygen index (LOI) and vertical burning tests. Thermal, mechanical properties, and whiteness of the treated cotton fabric were also assessed. The results demonstrate that this treatment could impart cotton fabric with flame retardancy due to the chemical bond formed between the flame retardant agent and the substrate.

Durable flame retardant finishing of cotton fabrics with halogen-free organophosphonate by UV photoinitiated thiol-ene click chemistry

Cotton fabrics are treated with a synthetic non-halogenated organophosphorus flame retardant by UV photoinitiated thiol-ene click chemistry. Thiol reactive precursors on cotton surface were prepared by 3-Mercaptopropyltriethoxysilane. The flame retardant property has been tested with different concentrations of flame retardant treatment (i.e., wt 2%, 5%, and 8%) by limited oxygen index (LOI) and vertical burning tests and maintained after 30 washing cycles, which was improved with concentration increases. Thermogravimetric analysis showed that the treatment greatly enhanced the char forming ability of cellulose and the highest residue was left as much as 48.1% char in nitrogen and 19.8% char in air after heating to 600°C, which obviously more than those of untreated fabric. Scanning electronic microscopy (SEM) revealed that the weave structure and fiber shape in all treated fabrics were preserved. These results demonstrate that UV photoinitiated thiol-ene click chemistry is a facile method for imparting cotton fabric with durable flame-retardant properties.

Construction of fiber-based BiVO 4 /SiO 2 /reduced graphene oxide (RGO) with efficient visible light photocatalytic activity

The visible light-responsive photocatalyst BiVO4/SiO2/reduced graphene oxide (RGO) was synthesized by hydrothermal method. For easy collection and reuse in slurry systems, RGO/BiVO4/SiO2 was immobilized on the cotton fiber by ultrasonic-heating technology. The characterization results indicated that the surface of cotton fiber was uniformly covered with BiVO4/SiO2/RGO photocatalyst. The loaded BiVO4/SiO2/RGO endowed the composite fibers with an excellent photocatalytic activity and recyclability for the degradation of the C.I. Reactive Blue 19 under visible light irradiation. The introduction of RGO exhibited the great dispersibility of photocatalyst in aqueous solution and the high absorbance of positive metal ions, which enhanced its photocatalytic performance. Given the above research results, the flexible fiber-based BiVO4/SiO2/RGO composite would have potential applications in the water/air purification field.

Electromagnetic wave absorption polyimide fabric prepared by coating with core–shell NiFe2O4@PANI nanoparticles

The nickel ferrite@polyaniline/polyimide (NiFe2O4@PANI/PI) fabric was prepared by coating the PI fabric with core–shell NiFe2O4@PANI nanoparticles to obtain an excellent microwave absorption performance. Firstly, a microwave absorbing agent was fabricated by dispersing the pre-synthesized core–shell NiFe2O4@PANI nanoparticles into epoxy monomer, in which the covalent bonding between epoxy groups and amine groups from PANI made them uniformly disperse. Then the agent was coated on to the PI fabric to a thickness of 0.12 mm. The results of field effect-transmission electron microscopy and scanning electron microscopy demonstrated the core–shell structure of NiFe2O4@PANI and the composite structure of the NiFe2O4@PANI/PI fabric. The resultant fabric possessed a high microwave attenuation property with a minimum reflection loss value of −19.2 dB (>90% attenuation) at 16.1 GHz and the effective absorption bandwidth was 5.1 GHz. This high performance was attributed to the uniform dispersion of core–shell NiFe2O4@PANI nanoparticles, better impedance matching and intensive synergistic effect between dielectric loss caused by the PANI shell and magnetic loss from the NiFe2O4 core. The favorable flexibility, processability and high tensile properties gave the composite fabric a long service time under pressure or foldable conditions. Furthermore, this process was environmentally friendly as no organic solvent was used in the whole process and the NiFe2O4@PANI/PI fabric could potentially be applied in microwave absorbing fields.

Study of a polyaniline/polypropylene collecting electrode and its particle removal efficiency

In this study, we successfully prepared conductive polyaniline (PANI) on a polypropylene (PP) plate to produce novel collecting electrodes for the removal of fine particles. The PANI/PP plates were assembled on an arrayed collector to produce high particle removal efficiency in an electrostatic precipitator. The PANI/PP plate was characterized using FT-IR spectroscopy, XRD, TG, SEM and EDS. The particle removal efficiency of the collecting plates can reach 90% for PM2.5. Furthermore, the effects of wind velocity, the space between the collecting plates and the surface resistance of the collecting electrodes, and the number of washing cycles on the particle removal efficiency were discussed.

Durable antibacterial finishing of cotton fabric based on thiol–epoxy click chemistry

This research proposes a method based on thiol–epoxy click chemistry to achieve durable antibacterial properties on cotton fabrics. The cotton fabric was first modified with 3-mercaptopropyltriethoxysilane (KH-580) to introduce thiol groups. Then, cotton fabric was treated with a quaternary ammonium salt by thiol–epoxy click chemistry. The surface morphology of the treated fabrics and the reaction mechanism were confirmed by FTIR, EDS, and SEM. The antibacterial activity, dyeing performance, and mechanical properties of the treated cotton fabrics were also assessed. The E. coli antibacterial rate was about 99.44% and the S. aureus antibacterial rate was about 95.93%, with only a slight decrease after 30 cycles of washing, to 93.89% and 88.62%, respectively. The results demonstrated that this treatment effectively imparted the cotton fabric with durable antibacterial properties due to the chemical bonding formed between the quaternary ammonium salt and the substrate.

Preparation of antibacterial keratin fabrics via UV curing and click chemistry

A clean and cost-effective surface modification method of keratin fabrics was proposed by UV curing and thiolene click reaction. This method introduced a novel water-soluble photoinitiator 2,2-dimethylol propionic acid used in the UV curing process to avoid pollution caused by organic solvents. Pretreatment with tris(2-carboxyethyl)phosphine as a mild reducing agent was carried out to produce thiol groups on the surface of biological substrates. Then, diallyl dimethyl ammonium chloride was grafted onto the surface of the pretreated substrate through thiol–ene click chemistry under UV irradiation. The reaction was confirmed by SEM, FTIR spectra, TGA and XPS analysis. The experimental results demonstrate that this reaction can impart keratin fabrics with excellent antibacterial activity, antistatic properties and hydrophilicity.

Functional modification of wool fabric by thiol-epoxy click chemistry

The paper reports modification and characterization of wool fabrics achieved through thiol-epoxy click chemistry. A pretreatment with tris (2-carboxyethyl) phosphine (TCEP) as an effective reducing agent was carried out to produce thiol groups on wool surface. Glycidyl trimethyl ammonium chloride (GTAC) was later covalently bonded with wool fibers via thiol-epoxy reaction. The reaction was confirmed by SEM, FTIR, Raman and TG analysis. Antibacterial activity, antistatic property, hydrophilicity and dyeability of treated wool fabric were assessed. The results demonstrated that TCEP-GTAC treatment can endow wool fabric good antibacterial and antistatic properties as well as improved hydrophilicity. Tensile strength studies indicated fiber strength loss of ~12 % on modification.

Preparation and properties of copper-silver complex plating on PET fabrics

This paper proposes a facile way to fabricate PET fabrics with electromagnetic shielding effect and conductive properties through preparing autocatalytic carboxylic styrene butadiene latex film with catalyst PdCl2, and followed with copper electroless plating and silver electroplating. The influence of operating parameters on copper and silver complex plating was investigated. The copper-silver layer was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX). The rate of weight gain, deposition rate and layer adhesion strength were also analyzed. The results indicated that copper-silver complex layer formed on PET surface was imparted with good electrical conductivity, fine uniformity and high compactness.

Synthesis and characterization of hybrid latexes from soybean oil-based polyurethane and poly(2,2,2-trifluoroethyl methacrylate)

A class of novel fluorine containing core-shell hybrid latexes were obtained from soybean oil-based polyurethanes and poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) by two-step synthesis under mild reaction conditions. Structural and morphology properties of the resulting hybrid latexs have been characterized by FT-IR and TEM. In addition, thermal properties (DSC, TGA) and coating performance (contact angle, stress-strain curve, and surface free energy) were investigated and discussed. The hybrid latexes exhibit outstanding thermal stability and coating performance. More importantly, through this method, low-valued foods are successfully transformed into high-valued functional materials which bring new solutions for preparing materials from renewable sources.