Nanofiber mats oxide nanofibers

Vondran JL, Sun W, Schauer CL (2008) Crosslinked, electrospun chitosan-poly(ethylene oxide) nanofiber mats. J Appl Polym Sci 109(2) 968-975... 

Composites of PANI-NFs, synthesized using a rapid mixing method, with amines have recently been presented as novel materials for phosgene detection [472]. Chemiresistor sensors with nanofibrous PANI films as a sensitive layer, prepared by chemical oxidative polymerization of aniline on Si substrates, which were surface-modified by amino-silane self-assembled monolayers, showed sensitivity to very low concentration (0.5 ppm) of ammonia gas [297]. Ultrafast sensor responses to ammonia gas of the dispersed PANI-CSA nanorods [303] and patterned PANI nanobowl monolayers containing Au nanoparticles [473] have recently been demonstrated. The gas response of the PANI-NTs to a series of chemical vapors such as ammonia, hydrazine, and triethylamine was studied [319,323]. The results indicated that the PANI-NTs show superior performance as chemical sensors. Electrospun isolated PANI-CSA nanofiber sensors of various aliphatic alcohol vapors have been proven to be comparable to or faster than those prepared from PANI-NF mats [474]. An electrochemical method for the detection of ultratrace amount of 2,4,6-trinitrotoluene with synthetic copolypeptide-doped PANI-NFs has recently been reported [475]. PANI-NFs, prepared through the in situ oxidative polymerization method, were used for the detection of aromatic organic compounds [476]. 

Electrospinning processes are used to prepare nanocomposite fiber mats. In order to prepare nanocomposite fiber mats, mixtures containing the polymer solution and cellulose whiskers solution are placed in the appropriated electrospinning setup. Peresin et al. [128] have produced nanocomposite mats of poly (vinyl alcohol) (PVA) reinforced with cellulose nanocrystals using this electrospinning technique. Smooth nonwoven mats with homogeneous nanofibers were obtained. Park et al. [129] have also incorporated cellulose whiskers into nanofibers of polyethylene oxide (PEO) by the electrospiiming process. 

To improve PANI processability, the first approach to obtain polyaniline doped with camphorsulfonic acid (PANI-CSA) and doped nanofibers blended with common pol5miers by electrospinning was done by MacDiarmid s group. In another study a nonwoven mat was obtained by using a PANI/poly(ethylene oxide) (PEO) solution dissolved in chloroform. By controlling the ratio of PANI to PEO in the blend, fibers with conductivity values comparable to that of PANI-CSA/PEO cast films were produced. 

Kim, G., Yoon, K, and Park, Y. (2010) Drug release fi-om various thicknesses of layered mats consisting of electrospun poly caprolactone and polyethylene oxide micro/nanofibers. Appl. Phys. A Mater. Sci Process., 100, 1197—1204. 

Preliminary studies were performed to find optimum condition for electrospinning of PVA solution. The SEM photomicrographs of electrospun PVA nanofibers from 10% solution showed that there was a uniform nanofibers with diameter ranging from 150 to 400 nm, average diameter of 350 nm. As the polymer concentration increased, a mixture of beads and fibers were formed. Therefore, PVA concentration of 10% was used for preparation of electrospun nanofibers. A series of mats were prepared from the 10% PVA solution in mixture with various amount of FeCl3 or ammonium persulfate ((NH )jSj03) as oxidant at the 15 KV constant electric field. 

The vapor phase chemical deposition of PPy on the surface of the electrospun PVA nanofibers was successfully performed. Morphology of the nanofibers and successful deposition of the PPy onto the nanofibers is governed by the oxidant type and its concentration in the electrospinning solution. At the best studied condition, a layer of PPy with the thickness of 1,000 nm is formed onto the PVA nanofibers surface using ammonium persulfate as oxidant. In contrast, surface coating was not observed in the case of FeClj as oxidant. The electrical conductivity of the coated nanofiber mats depends on the coating conditions and reaches to 10 S/cm. Large surface area of the sensor material with the electrochemical activity is one of the most important properties for sensor application. Since, it is obvious that the surface area of PPy coated non-... 

Scientists investigated the electrochemical catalytical properties based on Pd/polyamide (Pd/PA6) electrospun nanofiber mats for the oxidation of ethanol in alkaline medium in which Pd/PA6 was directly used as electro-catalytic electrodes. 

Progress made in electrospinning in the past decade has allowed for the production of fibers in nanoscale diameters from various polymers. Tissue engineering has benefited a lot from this process and quite often silk protein is used to produce nanofiber scaffolds for ceU cultures. Human bone marrow stromal cells were found to proHferate in vitro very well on mats made from poly(ethylene oxide) (PEO) and B. mori silk aqueous solution electrospun nanofibers [27]. A very interesting work by... 

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