Electrospinning is a relatively simple method to produce submicron fibers from solutions of different polymers and polymer blends. The extensive application in future of electrospinning nanofibers is filtration. In this article, the filtration properties of electrospinning nanofibers were investigated. During the experiments, nanofibers layers with different area weight were electrospun on the spunbonded or meltblown sublayers. Fiber diameter, pore diameter, filtration efficiency as well as filtration resistance of nanofibers web and sublayers were measured, respectively, through a series of experiments. The results show that the fiber diameter of nanofibers is much smaller than that of sublayers. It is also found that the pore diameter of nanofibers web is much smaller than sublayers and coefficient variation of the pore diameter of nanofibers web is much smaller than sublayers. Moreover, the filtration efficiency and filtration resistance of sublayers are lower than nanofibers webs. The balance between efficiency and press drop is also investigated in the article.

Nanoscaled crosslinked poly(vinyl alcohol) PVA fibers were prepared by electrospinning. This study described its electrospinning process, structure, and filtration applications. The fibers were found to be efficiently crosslinked by maleic acid. Vitriolic acid was used as a catalyst activator during crosslinking. Scanning electron micrograph and differential scanning calorimetric techniques as well as infrared reflection-absorption spectroscopy (FTIR) were employed to characterize the morphology and structure of crosslinking of PVA fibers, PVA fibers as well as PVA powder. Moreover, the filtration properties of crosslinked PVA nanofibers were tested. During the experiments, crosslinked PVA nanofibers layers with different area weight were placed on the spunbond or meltblown sublayers. The result shows that the filtration efficiency increases sharply when crosslinked PVA nanofibers layers were added to the sublayers.2008 Wiley Periodicals, Inc. J Appl Polym Sci 109: [951][952][953][954][955][956] 2008

A theoretical model for electro-mechanical properties of intrinsically conductive knitted fabrics made from stainless steel multi-filament yarns under large uniaxial deformation is presented. The investigations are focused on the relationship between the load and electrical resistance of the fabric under uniaxial extension. A circuit network is proposed based on the loops configuration and fabric structure. The equivalent resistance of the fabric is obtained by solving the circuit equations of the network. In order to simplify the calculation of the contacting forces on the overlapped yarns, a two-dimensional hexagon model is used to represent the loop configurations. An image-capturing system is employed to record the images of the loop configurations during the extension process and the relationship between the configurations of the loops and the load imposed on the fabric is obtained. From the theoretical analysis and experimental investigations, it is found that the contacting resistance of the overlapped yarns in the fabric is the key factor that governs the sensitivity of the fabric sensor. In addition, the fabric structure that determines the structure of the circuit network is also an important factor affecting the characteristics of the fabric sensor.Knitted fabrics are used widely in clothing but being used as sensors for measuring strain and temperature based on their loop configurations are quite novel applications of conductive knitted fabrics [3]. The elastic and extendable substrates of the fabrics make it feasible for these sensors to be used for measuring large tensile strain.The applications of these conductive fabric sensors are based on the changes of the electrical resistance responding to stimuli such as deformation, temperature, humidity, as well as some chemicals. Hence, the resistancestimulus responses are the bases that provide the sensitivity of the fabric sensors. To date, many conductive materials and special fabric sensors have been produced accordingly [1,2,4,8,16]. Several papers have described experimental investigations of the relationships between the load/elongation and electrical resistance of the conductive fabrics [5,9,12]. However, few studies have reported on the mechanism of the conductive fabrics and the key factors of the sensitivity in detail. A theoretical model of electro-mechanical behavior of plain woven fabric made from intrinsically conductive yarn has been proposed, and relationships between the electrical resistance and fabric density, as well as uniaxial tension have been developed [10,18]. In our paper, the electro-mechanical properties of knitted fabrics made from stainless steel multi-filament yarns are investigated both theoretically and experimentally. Theoretical BASIC ASSUMPTIONSThe conductive knitted fabric is treated as a conducting body as the metallic yarn is intrinsically conductive, and the unit length resistance of the yarn is considered

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We present a facile approach to immobilizing zerovalent iron nanoparticles (ZVI NPs) into electrospun polymer nanofibrous mats. Electrospun poly(acrylic acid) (PAA)/poly(vinyl alcohol) (PVA) nanofibrous mats were treated at an elevated temperature to render them water stable. The water-insoluble nanofibrous mats were then used as nanoreactors to complex ferric iron for subsequent formation and immobilization of ZVI NPs. Scanning electron microscopy (SEM) studies show that the smooth, uniform morphology of the electrospun nanofibrous mats does not significantly change after immobilization with ZVI NPs. Energy-dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), and thermogravimetric analysis (TGA) were used to characterize the polymer nanofibers before and after the immobilization of ZVI NPs. We show that the formed ZVI NPs are uniformly distributed into the electrospun nanofibers with a mean particle size of 1.6 nm. The produced ZVI NP-containing polymer nanofibrous mats exhibit a superior capability to decolorize acid fuchsine solution, a model dye in wastewater of printing and dyeing industry. Findings from this study suggest a significant potential of using the electrospun nanofibers as nanoreactors to synthesize reactive iron NPs for a broad range of environmental remediation applications providing a foundation for further rational design of various composite nanofibrous materials for various applications.