Effects of the Hot-Drawing Process on the Pore Parameters, Gas Absorption and Mechanical Performances of Activated Carbon-Loaded Porous Poly(m-Phenylene Isophthalamide) Composite Fibres.

Poor breathability, inadequate flexibility, bulky wearability, and insufficient gas-adsorption capacity always limit the developments and applications of conventional chemical protective clothing (CPC). To create a lightweight, breathable, and flexible fabric with a high gas-absorption capacity, activated carbon (AC)-loaded poly(m-phenylene isophthalamide) (PMIA) porous composite fibres were fabricated from a mixed wet-spinning process integrated with a solvent-free phase separation process. By manipulating the pore parameters of as-spun composite fibres, the exposure-immobilization of AC particles on the fibre surface can offer a higher gas-absorption capacity and better AC-loading stability.

Co single-atom catalyst for efficient and long-acting activation of peroxymonosulfate: Formation of Co-N site and insight into the activation mechanism.

While single-atom catalysts (SACs) have been extensively investigated as a high-atom-efficiency heterogeneous catalyst for peroxymonosulfate (PMS) oxidation reaction, the stable constructing and activation efficacy of the reaction sites remains less clarified. Herein, we employed gelatin as a N,O-bidentate ligand for Co (II) to form for a N-doped carbon precursor, while introducing NaCl as a template agent to induce the adoption of a Co-N conformation and disorganize the Co-O moiety. This approach facilitates uniform spatial isolation and atomic-level dispersion of Co atoms within the aerogel, effectively inhibiting the aggregation of Co during synthesis and enabling precise and controllable preparation of Co single-atom catalysts (SACs).

Heparin-modified polyether ether ketone hollow fiber membrane with improved hemocompatibility and air permeability used for extracorporeal membrane oxygenation.

To expand the selection of raw material for fabricating extracorporeal membrane oxygenation (ECMO) and promote its application in lung disease therapy, polyether ether ketone hollow fiber membrane (PEEK-HFM) with designable pore characteristics, desired mechanical performances, and excellent biocompatibility was selected as the potential substitute for existing poly (4-methyl-1-pentene) hollow fiber membrane (PMP-HFM). To address the platelet adhesion and plasma leakage issues with PEEK-HFM, a natural anticoagulant heparin was grafted onto the surface using ultraviolet irradiation. Additionally, to explore the substitutability of the heparin layer while considering cost and scalability, a heparin-like layer composed of copolymers of acrylic acid and sodium p-styrenesulfonate was also constructed on the surface of PEEK-HFM Even though the successful grafting of heparin and heparin-like layers on the PEEK-HFM surface reduced the pore parameters, improvements in surface hydrophilicity also prevented the platelet-adhesion phenomenon and improved the anticoagulant behaviour, making it a viable alternative for commercial PMP-HFMs in ECMO production.

Improve the Crosslinking Reactivity of Nitrile: Design of Nitrile-Functionalized Pyrazine and its Hydrogen Bond-Assisted Nucleophilic Enhancement Study.

In this study, molecular engineering and biomimetic principles are utilized to prepare highly effective nitrile-functionalized pyrazine crosslinking units by exploiting pyrazine's unique nucleophilic strengthening mechanism and proton bonding ability. The curing behaviors of pyrazine-2,3-dicarbonitrile and phthalonitrile are investigated through model curing systems and molecular simulation. The results indicate that pyrazine-2,3-dicarbonitrile exhibits higher reactivity than phthalonitrile, promoted by amine.

Halogen-Free Flame Retardant Polypropylene Fibers with Modified Intumescent Flame Retardant: Preparation, Characterization, Properties and Mode of Action.

A novel intumescent flame retardant (IFR) agent designated as Dohor-6000A has been used to prepare halogen-free flame retardant polypropylene (PP) fibers via melting spinning. Before being blended with PP resin, a surface modification of Dohor-6000A was carried out to improve its compatibility with the PP matrix. The rheological behavior of flame retardant Dohor-6000A/PP resin, the structure, morphology, mechanical properties, flammability of the Dohor-6000A/PP fibers were studied in detail, as well as the action mode of flame retardant.

Improving interfacial and mechanical properties of glass fabric/polyphenylene sulfide composites grafting multi-walled carbon nanotubes.

The interfacial strength between reinforced fiber and a polymeric matrix is a critical factor for determining the mechanical properties of composites. Here, grafting multi-walled carbon nanotubes (MWCNTs) onto plain weave glass fabric (PWGF) is introduced to improve the interfacial strength of PWGF reinforced polyphenylene sulfide (PPS) composites. Firstly, MWCNTs-g-PWGF is prepared by grafting oxidized MWCNTs onto functionalized PWGF, and then the MWCNTs-g-PWGF/PPS composite laminates are fabricated by an opening hot pressing process.

Pore Structure and Properties of PEEK Hollow Fiber Membranes: Influence of the Phase Structure Evolution of PEEK/PEI Composite.

Poly(ether ether ketone) (PEEK) hollow fiber membranes were successfully prepared from miscible blends of PEEK and polyetherimide (PEI) via thermally-induced phase separation (TIPS) with subsequent extraction of the PEI diluent. The phase structure evolution, extraction kinetics, membrane morphology, pore size distribution and permeability for the hollow fiber membrane were studied in detail. Extraction experiments, differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMA) studies showed that the heat treatment had a significant influence on the two-phase structure of PEEK/PEI, and that it was controlled by the crystallization kinetic of PEEK and the diffusion kinetic of PEI.

Structure and properties of halogen-free flame retardant and phosphorus-containing aromatic poly(1,3,4-oxadiazole)s fiber.

In order to improve the flame retardance of aromatic polyoxadiazole (-POD) fiber, a series of phosphorus-containing PODs (pho-POD) were synthesized by introducing triaryl phosphine oxide (TPO) units into the main chains of -POD using hydrazine sulfate, terephthalic acid and bis(-carboxy)phenyl phosphine oxide (BCPPO) as monomers, and then halogen-free flame resistant pho-POD fibers were obtained from wet spinning. The structure and properties of the pho-POD fibers were characterized and measured in detail using the methods of wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), the limiting oxygen index (LOI), oxygen bomb calorimeter, Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) The results show that the introduction of TPO units resulted in the weakening of the crystallization ability, the formation of the poriferous and lax interior structure, the slight decrease in the thermal stability and mechanical properties of the POD fibers. However, the value of LOI obviously increased from 28% to 35%, and the gross heat of combustion (GHC) decreased from 19.

Stress-memory polymeric filaments for advanced compression therapy.

Shape memory polymers are stimulus responsive smart materials that can be applied in several forms such as films, fibers, and foams for a wide range of applications. Novel stress-memory behavior at a fiber level is yet to be uncovered, which would be favorable to control stress in the broad horizon of smart materials for numerous functions. In this work, a semi-crystalline segmented polyurethane was synthesized to prepare filaments/fibres and films.