In this paper, polyethersulfone (PES) magnetic microspheres were prepared via an in situ reaction method. Firstly, the PES microspheres were produced by an electrospray method and then the magnetic properties were delivered to the microspheres through in situ reaction. Scanning electron microscopy (SEM) coupled with image analysis software, transmission electron microscopy (TEM), and X-ray diffraction (XRD) were employed to investigate the structure and morphology of the magnetic microspheres. The results indicate that the majority of the magnetic nanoparticles are dispersed uniformly and embedded into the surface of the PES electrosprayed microspheres. A vibrating sample magnetometer was used to evaluate the magnetic properties of the PES magnetic microspheres and the saturation magnetization values were found to be up to 23.96 emu g−1. A separation test showed that the prepared magnetic microspheres can realize fast separation under an external magnetic field. Additionally, compared with the original microsphere counterparts, PES magnetic microspheres exhibited better adsorption capacity and reuse performance in adsorption tests. These results indicate that the PES in situ magnetic microspheres have the potential to be used in water treatment and environmental depuration.

In this paper, polyethersulfone (PES) magnetic microspheres were prepared via an in situ reaction method. Firstly, the PES microspheres were produced by an electrospray method and then the magnetic properties were delivered to the microspheres through in situ reaction. Scanning electron microscopy (SEM) coupled with image analysis software, transmission electron microscopy (TEM), and X-ray diffraction (XRD) were employed to investigate the structure and morphology of the magnetic microspheres. The results indicate that the majority of the magnetic nanoparticles are dispersed uniformly and embedded into the surface of the PES electrosprayed microspheres. A vibrating sample magnetometer was used to evaluate the magnetic properties of the PES magnetic microspheres and the saturation magnetization values were found to be up to 23.96 emu g−1. A separation test showed that the prepared magnetic microspheres can realize fast separation under an external magnetic field. Additionally, compared with the original microsphere counterparts, PES magnetic microspheres exhibited better adsorption capacity and reuse performance in adsorption tests. These results indicate that the PES in situ magnetic microspheres have the potential to be used in water treatment and environmental depuration.

Conductive electrospun fibers have attracted widespread interest in the field of electromagnetics. However, the problem of how to effectively improve the electrical conduction of electrospun fibers has still not been adequately addressed. In this study, a new, simple and effective method was introduced to significantly improve the conductive properties of fibers. PES/PVA fibers with previous addition of 20 wt% PVA were chosen as a matrix due to the large parallel porous structure. The carbon nanotubes (CNTs) were first absorbed by the PES/PVA fibers, and then a thin polymer/CNTs composite layer was self-formed on the surface of the porous fibers by vapor treatment. Most importantly, a CNTs network structure was also formed in this vapor process, which easily gave the porous fibers a significant enhancement in conductivity with only a small amount of CNTs. Electrical conduction tests showed that the conduction of the fibers increased with increasing CNT content, and attained the maximum value when the amount of CNTs was around 7 wt%. The adsorption time and the DMSO vapor treatment time were optimized to obtain the best thin polymer/CNT composite layers. The surface microstructure of the composite layer was observed using scanning electron microscopy (SEM) and TGA. The results showed that this novel, powerful method could potentially be used to prepare novel types of conductive polymer fibers.

The focus of this work was the preparation of hollow ultrafine fibers with a multilayer wall via coaxial electrospinning technology in one step and then studied their drug delivery properties. In this paper, by choosing a suitable dilute hydrophilic polymer solution as the core solution, polyethersulfone (PES) hollow ultrafine fibers with two different layers wall (porous structure layer and dense smooth layer) were formed during coaxial electrospinning process in one step. They showed good drug delivery capacity when curcumin was used as the model drug. There were much larger delivery amounts, more stable release rate, and higher utilization rate of PES hollow ultrafine fibers with a multilayer wall to curcumin than that of PES porous ultrafine fibers. Compared with porous ultrafine fibers, hollow ultrafine fibers with two different layers wall were more suitable to be used as drug delivery materials. Besides, between the two hollow ultrafine fibers with two different layers wall mentioned in this paper, there was much better drug delivery capacity for the hollow fibers produced with the core solution of PVA/DMSO. These results showed that PES hollow ultrafine fibers with two different layers wall have the potential to be used as the drug delivery materials.

We for the first time report a novel method to achieve the morphology control of two kinds of dimensional different nanofillers, the platelike nanoclay and globelike SiO2, by using their “filler to filler” interaction in poly (phenylene sulfide) (PPS). The strong interaction between layered nanoclay and rigid SiO2 is obtained by their different response to shear flow in PPS melt processing. As a result, the exfoliation structure of nanoclay and well-dispersed nano-SiO2 are realized simultaneously. With this successful morphology control, the reinforcement effect of nanofillers in PPS is improved with very little addition. Moreover, with the restriction of exfoliated clay and nano-SiO2 particles, the mobility of PPS molecular chains is confined, leading to the significant change in crystalline behaviors of PPS.

Two kinds of aromatic polyesters containing thioether units had been prepared through the reaction of 4,4′-thiodibenzoyl chloride (T-DC) (or 4,4′-bis(4-chloroformylphenylthio)benzene (BPBDC)) and 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BHPPE) by the method of interfacial polycondensation. These polyesters showed good solubility, and could afford tough films with tensile strengths of 103.6–108.3 MPa. The glass transition temperature (Tg) of these polyesters ranged from 189.8 to 235.6 °C and initial degradation temperatures (Td) were 450–454 °C. The activation energies of degradation were in range of 156.6–160.3 KJ/mol. The limiting oxygen indexes (LOIs) of these polyesters ranged from 37 to 39, and UL-94 V-0 rating could achieve via this approach. The thermal degradation kinetics and thermal pyrolysis mechanism of these polyesters was studied by thermogravimetric analysis and Py-GC/MS analysis, respectively.

In this work, we compare the tensile behaviors of two kinds of PPS samples, the mould temperature control sample and thermal curing sample, which undergoing different thermal histories. Based on the SAXS and WAXD results, the crystal structure of PPS is not destroyed in stretching due to its higher Tg. However, the maximum stress value of thermal curing sample is higher than that of mould temperature control sample, though the contribution of crystal phases are the same since their same crystallinity and grain size. The result indicates that the stress of PPS is not only decided by crystal phase (crystallinity) but amorphous phase: the crystal structures carry most part of the stress in stretching process, and the restricted amorphous chains could also carry partial tensile stress. Correlating the possible structure change with mechanical property, it is reasonable to believe higher entanglement density of molecular chains in amorphous phase could lead to more restricted chains, thus giving a higher stress value to thermal curing sample. The theoretical model is proposed to explain the correspondence between micro-structure and macroscopical performance.

A salt-induced electrospinning method to produce porous polymer ultrafine fibers was reported in this work. Scanning electron microscopy, energy dispersive spectrometer, and BET surface area measurement were employed to evaluate the morphology, the element distribution, and the surface area of fibers, respectively. According to the investigation result, pores on the fiber were induced by water-soluble salt during electrospinning process in a humid spinning environment. There was no porous structure on the fiber surface when water-insoluble salt was used in a wet electrospinning environment or when water-soluble salt was used in a dry electrospinning environment. Compared with pure fibers, the average surface area of fibers containing salt increased significantly due to the porous structure. The possible mechanism of the porous structure induced by salt was proposed. Water-solubility salt and humid environment were considered as the key roles in the formation of porous structure. This method provided a new way to form porous structure during electrospinning.