Shaojuan Chen

Electromagnetic interference shielding cotton fabrics with high electrical conductivity and electrical heating behavior via layer-by-layer self-assembly route

In our paper, multi-functional cotton fabrics with electrical and electromagnetic interference (EMI) shielding properties via layer-by-layer (LbL) electrostatic self-assembly approach were prepared. Chitosan was adopted as a polycation with graphene added by solution mixing, and poly(sodium 4-styrenesulfonate) (PSS) as a polyanion was deposited on cotton fabric substrate followed by the chitosan–graphene layer alternatively. Structural and morphological characterizations of the prepared LbL samples were carried out using SEM, AFM, XPS, and surface potential techniques. As expected, surface potential value exhibited an obvious “odd–even” regular pattern, which results from the alternating deposition of PSS and chitosan–graphene layers. Further, the electrical conductivity of the 10-layer-deposited fabric reached 1.67 × 103 S m−1. The fabric also exhibits ultrastrong electromagnetic interference (EMI) shielding ability with a maximum SE value of 30.04 dB. The LbL fabric also possesses excellent electrical heating behaviors. The temperature of the resultant fabric would monotonically rise to the steady-state maximum value (ΔTmax) of 134 °C within 8 min when 7 V voltage was applied, and exhibit excellent stability and recyclability. In addition, various performances remained almost unchanged after 10 consecutive washing treatments. The modified cotton fabric with lightweight, flexible and high-performance EMI shielding properties could be applied in personal protective garments and industrial textiles.

Fabrication of Dielectric Elastomer Composites by Locking a Pre-Stretched Fibrous TPU Network in EVA

Dielectric elastomer (DE) composites with high electrical breakdown strength and large voltage-induced deformation were developed by retaining pre-stretched thermoplastic polyurethane (TPU) fibers in ethylene vinyl acetate copolymer (EVA). The microstructure of the candidate E-TPU fiber membrane and EVA coated E-TPU (E-TPU/EVA) film were characterized by scanning electron microscopy (SEM). The quasi-static and dynamic mechanical property, and the electromechanical properties, including the dielectric constant, dielectric loss tangent, and electromechanical sensitivity, of the DE composites were evaluated. Initially, tensile tests demonstrated that the DE composites based on E-TPU/EVAs had a higher elongation at break of above 1000% but a low elastic modulus of approximately 1.7 MPa. Furthermore, dielectric spectroscopy showed that the E-TPU/EVA had a dielectric constant of 4.5 at the frequency of 1000 Hz, which was 1.2 times higher than that of pure EVA film. Finally, it was found from electromechanical test that the voltage induced strain of E-TPU/EVA rose to 6%, nearly 3 times higher than that of pure TPU film, indicating an excellent electromechanical property. The DE composites developed have demonstrated the potential to be good candidate materials in the fields of artificial intelligence, biomimicry and renewable energy.

Modification of Polytetrafluoroethylene-fiberglass Composite Film Using Polydopamine Deposition with Improved Hydrophilicity

The surface of polytetrafluoroethylene (PTFE)-fiberglass composite film was modified with polydopamine (PDA) in order to improve hydrophilic properties and hence to expand its perspective usage for biomedical and blood-contacting applications. Scanning electron microscopy, atomic force microscopy, energy dispersive spectrometer and fourier transform infrared spectra were employed to analyse the surface morphology and the chemical structures of the modified PTFE-fiberglass composite films. Hydrophilic property of PTFE-fiberglass composite films was investigated by using water contact angle measurement. The effect of treatment time on the surface morphology and hydrophilicity of PTFE-fiberglass composite films was investigated. The results showed that a dense layer of PDA was formed on PTFE-fiberglass composite films, the water contact angle decreased gradually with the increase in modification time. Moreover, the fastness of PDA layers deposited on the PTFE-fiberglass composite films was studied by using UV/VIS/NIR spectrometer. It was revealed that the PDA layer was stable in distilled water, 0.1 M hydrochloric acid solution and alcohol, but had a poor resistance to 0.1 M sodium hydroxide solution.

Numerical prediction of degree of skin burn in thermal protective garment-air gap-human body system

Ming-Wei TIAN , Wang ZHEN , Wang LIN , Li-Jun QU , Shao-Juan CHEN , Shi-Feng ZHU , Rong-Rong YU , Ren-Hai ZHAO , and Hong-Tao ZHAO a a College of Textiles of Clothing, Qingdao University, Qingdao, Shandong, China b Laboratory of New Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong, China c Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong, China d SINOPEC Safety Engineering Institute, Qingdao, Shandong, China