Linya Yan,Jinfeng Wang,Ying Mao,Hongshi Zhao,Wenxing Chen,Wangyang Lu
Currently, synthetic materials for soft tissue repair are non-biodegradable and rigid, while biodegradable natural polymer materials exhibit low mechanical strength. This study focuses on creating biodegradable silk patches with superior mechanical properties using warp knitting. Four kinds of silk patches were made, degummed, and their structural parameters and mechanical properties were evaluated. An orthogonal experiment was conducted to investigate the effects of heat-setting temperature and time on the patches' mechanical properties. The results show that the #D patch, with its moderate thickness and density, large and concentrated pores, high strength, and low elongation, closely resembles natural soft tissue. After heat setting at 120°C for 3 min, the mechanical properties significantly enhanced (up to 17.1%). The patch exhibited a longitudinal tensile strength of 276.81 N, transverse tensile strength of 330.73 N, burst strength of 1566.5 N, longitudinal tear strength of 307.33 N, transverse tear strength of 124.66 N, longitudinal suture pullout strength of 53.28 N, and transverse suture pullout strength of 73.89 N. This method of using warp knitting and digital weaving technology allows for the preparation of silk patches suitable for soft tissue repair, with high strength, stability, and porosity, making them ideal for tendon and rotator cuff repairs.
In order to remit the membrane wetting in membrane distillation (MD), polytetrafluoroethylene (PTFE) flat membrane with low surface free energy and high water contact angle (WCA) was prepared by a simple heat setting process. Membrane morphology evolution, such as breakage of fibrils and fusion of PTFE resin, and its influence on membrane characters including pore size, porosity and roughness were discussed. The effect of the heat setting process on the membrane wetting was evaluated by the membrane wetting time (MWT) in a static absorption experiment (SAE) and sweep gas membrane distillation (SGMD). The results show that the crystallinity decreases with increasing the heat setting temperature and time, which leads to low surface free energy and therefore low adsorbing capacity of penetrating agent and the long wetting time in the static absorption experiment and SGMD. In addition, pore size increases firstly and then decreases due to the breakage of fibrils and fusion of PTFE resin, respectively, which further affects the permeate flux . Therefore, we propose that the anti-fouling property and separation performance of PTFE flat membrane in SGMD can be well handled and hope that such a PTFE flat membrane would be potentially useful in seawater desalination .
The high-temperature industrial waste oil treatment has put forward new requirements for membrane materials. Poly (tetrafluoroethylene) (PTFE) is regarded as the excellent membrane material for membrane process, due to its excellent properties. Herein, the reinforced PTFE hollow fiber membrane (PTFE-HFM) was prepared by the combination of wrapping and heat setting technology. The objection of this study was focusing on the outstanding chemical and thermal resistance of PTEF-HFM for overcoming harsh waste oil treatment. PTFE-HFM exhibited better chemical resistance in the experiment of acid and alkali compared to PVDF-HFM, which the surface of PVDF-HFM corroded obviously and none of PTFE-HFM. The pore size and porosity were precisely adjusted by heat setting technology. Firstly, the morphologies of PTFE-HFM was investigated by scanning electron microscopy, which exhibited favorable interfacial bonding state between PTFE separation layer and supporting layer. Subsequently, the prepared membranes exhibited high-temperature waste oil permeability of 195 L m −2 h −1 bar −1 with only 3% attenuation in long-term operation. Besides, the rejection of lubricants contained activated carbon also reached to 99%. Overall, the facile preparation and excellent performance of robust reinforced PTFE-HFM highlights its great potential in treating high-temperature waste oil.
危险品化学品经营许可证（带存储）