Controllable large-scale processing of temperature regulating sheath-core fibers with high-enthalpy for thermal management

Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_(s) with excellent thermal and mechanical properties. Here, polyamide 6(PA6) based TRF_(s) with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF(TRF_(sc)) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials(ssPCM),dendritic silica@polyethylene glycol(SiO_(2)@PEG). With the aid of the sheath structure, the filling content of SiO_(2)@PEG can reach 30 %, so that the enthalpy of the TRF_(s) can be as high as 21.3 J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 min, and the temperature difference is 12.93℃. In addition, the mechanical strength of the prepared TRF_(sc) reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.

A Skin-Inspired Self-Adaptive System for Temperature Control During Dynamic Wound Healing

The thermoregulating function of skin that is capable of maintaining body temperature within a thermostatic state is critical.However,patients suffering from skin damage are struggling with the surrounding scene and situational awareness.Here,we report an interactive self-regulation electronic system by mimicking the human thermos-reception system.The skin-inspired self-adaptive system is composed of two highly sensitive thermistors(thermal-response composite materials),and a low-power temperature control unit(Laserinduced graphene array).The biomimetic skin can realize self-adjusting in the range of 35–42℃,which is around physiological temperature.This thermoregulation system also contributed to skin barrier formation and wound healing.Across wound models,the treatment group healed~10%more rapidly compared with the control group,and showed reduced inflammation,thus enhancing skin tissue regeneration.The skin-inspired self-adaptive system holds substantial promise for nextgeneration robotic and medical devices.

聚对苯二甲酸异山梨醇/乙二醇共聚酯及其熔纺纤维性能

通过三元共聚将生物基异山梨醇(Is)引入到聚对苯二甲酸乙二醇酯(PET)的分子链中,制备了系列聚对苯二甲酸异山梨醇/乙二醇共聚酯(PEIT)。进一步熔融纺丝获得了PEIT纤维。利用核磁共振波谱仪、凝胶渗透色谱、差示扫描量热仪、热重分析仪、X射线衍射仪及纤维强力仪分析研究了PEIT共聚酯的结构和性能。结果表明,Is刚性单元显著提高了PEIT的玻璃化转变温度(T g),保持了共聚物良好的热稳定性;同时破坏了分子链的规整性,使其结晶度有所降低。PEIT具有良好的可纺性,Is摩尔分数为5%时,PEIT纤维具有优异的力学性能,断裂强度较PET纤维增加了45%;仅当Is摩尔分数高于40%时,可拉伸性下降。

One-step floating conversion of biomass into highly graphitized and continuous carbon nanotube yarns

The rapid growth of the demand for carbon nanotubes(CNTs) has greatly promoted their large-scale synthesis and development. However,the continuous production of CNT fibers by floating catalyst chemical vapor deposition(FCCVD) requires a large amount of non-renewable carbon sources. Here, the continuous production of highly graphitized CNT yarns from biomass tannic acid(TA) is reported. The chelation of TA and catalyst promotes the rapid cracking of biomass into carbon source gas, and the pyrolysis cracking produces the reducing gas, which solves the problems of the continuous production of CNT yarns using biomass. Through simple twisting, the mechanical strength of CNT yarn can reach 886 ± 46 MPa, and the electrical conductivity and graphitization(IG/ID) can reach 2 × 10^(5)S m^(-1)and 6.3, respectively. This work presents a promising solution for the continuous preparation of CNT yarns based on green raw material.

Review:Scalable Fabrication of Polymeric Nanofibers from Nano⁃ Spinning Techniques to Emerging Applications

Research in the nanofibers field is attracting an ever-increasing attention from the industrial and academic sector. This attention is justified by the high specific surface area and high porosity, diversity of physical/chemical modification, and simplicity of hybridization. This review summarizes the state-of-the-art progress on the fabrication of polymeric nanofibers(PNFs) with particular emphasis on their scalable productions for emerging applications. First, the engineering processes and equipment for PNFs production are briefly introduced, and the effects of the polymer precursors, operational parameters, and environmental conditions on the nanofiber’s formation are illustrated. The past achievements and current challenges of PNF preparation in industrial production are also discussed. Hybridization methods to prepare multifunctional composite nanofibers are also reviewed, including organic incorporation modification, loading functional inorganic nanomaterials, and biological active components on/into nanofibers. Given these hybridizations and functions, a variety of applications are then discussed, focusing mainly on environmental and biomedical applications. Finally, conclusions are drawn and prospects are given according to the reviewed research.

Progress and Perspective of Antiviral Protective Material

Public health events caused by viruses pose a significant risk to humans worldwide.From December 2019 till now,the rampant novel 2019 coronavirus(SAR-CoV-2)has hugely impacted China and over world.Regarding a commendable means of protection,mask technology is relatively mature,though most of the masks cannot effectively resist the viral infections.The key material of the mask is a non-woven material,which makes the barrier of virus through filtration.Due to the lack of the ability to kill the viruses,masks are prone to cross-infection and become an additional source of infection after being discarded.If the filteration and antiviral effects can be simultaneously integrated into the mask,it will be more effcient,work for a longer time and create less difficulty in post-treatment.This mini-review presents the advances in antiviral materials,different mechanisms of their activity,and their potential applications in personal protective fabrics.Furthermore,the article addresses the future challenges and directions of mask technology.

Advances in Nonwoven‑Based Separators for Lithium‑Ion Batteries

Lithium-ion batteries(LIBs)are energy-storage devices with a high-energy density in which the separator provides a physical barrier between the cathode and anode,to prevent electrical short circuits.To meet the demands of high-performance batteries,the separator must have excellent electrolyte wettability,thermotolerance,mechanical strength,highly porous structures,and ionic conductivity.Numerous nonwoven-based separators have been used in LIBs due to their high porosity and large surface-to-volume ratios.However,the fabrication of multi-functional fibers,the construction of nonwoven separators,and their integration into energy-storage devices present grand challenges in fundamental theory and practical implementation.Herein,we systematically review the up-to-date concerning the design and preparation of nonwoven-based separators for LIBs.Recent progress in monolayer,composite,and solid electrolyte nonwoven-based separators and their fabrication strategies is discussed.Future challenges and directions toward advancements in separator technologies are also discussed to obtain separators with remarkable performance for high-energy density batteries.