A novel and convenient preparation of antibacterial polyacrylonitrile nanofibers via post-modification using nitrile click chemistry and electrospinning

Preparation of a novel sandwich-type electrochemical immunosensor for AFP detection based on an ATRP and click chemistry technique

It is extremely important to explore the synthesis methodology and application scope of functional polymer brush-based nanocomposites.

Sonication induced effective approach for coloration of compact polyacrylonitrile (PAN) nanofibers

We present our research on dyeability of polyacrylonitrile (PAN) nanofibers following ultrasonic dyeing method. Although PAN has been extensively utilized in textile apparel, sportswear, upholstery and home furnishing, however, coloration of PAN nanofibers has not yet been reported. PAN is a compact fiber while the nanofiber structure makes it more difficult to color PAN nanofibers. PAN is generally dyed with basic dyes and dyeing is carried out in acidic conditions, while the dyeing process takes about two hours at boiling temperature. A systematic study on dyeability of PAN nanofibers will extend its use in textile apparel industry. Thus, we used ultrasonic energy and first time conducted our research on dyeability of electrospun PAN nanofibers using disperse dyes. Dyeing process parameters such as dyeing time, temperatures and concentrations of dyes were optimized. Ultrasonic dyeing of PAN nanofibers was compared with its conventional dyeing as well. Affect of ultrasonic dyeing on the morphology, chemical state, crystallographic structure and mechanical strength of PAN nanofibers has been studied. PAN nanofiber samples were characterized by SEM, FTIR, XRD and tensile strength tests. The results revealed 80 °C and 60 min as optimum temperature and time for ultrasonic dyeing of PAN nanofibers. The ultrasonic dyeing does not affect morphology, chemical and crystalline structure of the PAN nanofibers while it improves their mechanical strength. Our research suggests dyeability of PAN nanofibers with disperse dyes by ultrasonic method and their subsequent use in textile apparels.

Preparation of immobilized lipase by modified polyacrylonitrile hollow membrane using nitrile-click chemistry

The application of immobilized lipase in the enzymatic production of biodiesel has shown numerous advantages. In this study, surface of Polyacrylonitrile (PAN) hollow membrane was first modified using nitrile-click chemistry in order to fit for interaction with enzyme proteins. Then sodium alginate (SA) was introduced and the membrane was post-treated by CaCl₂. When the prepared PAN-PEI-SA-CaCl₂ was used for lipase immobilization, the protein loading was 36.90 mg/g, and the enzyme activity reached up to 54.47 U/g, which was 2.5 times as much as that of Novozym® 435. As a result, the constructed immobilized lipase obtained a maximum biodiesel yield of 78.5%, which was 2.4 times that of the Novozym® 435 in transesterification reactions. Moreover, the biodiesel yield decreased by only 11% after the immobilized enzyme was continuously used for 20 times. This study exhibits that this technic has broad application prospects in the field of conversion of biomass resources.

The emerging applications of click chemistry reactions in the modification of industrial polymers

Click chemistry reactions have been applied to the modification of major industrial polymers by analysing the synthetic approaches and the resulting material properties.

Synthesis, Morphologies and Building Applications of Nanostructured Polymers

Nanostructured polymers (NSPs) are polymeric materials in the size of nanoscale, normally consisting of nanoparticles, nanofibers, nanowires, nanospheres and other morphologies. Polymer nanoparticles (PNPs) can be fabricated either by physical methods (i.e., solvent evaporation, nanoprecipitation, salting out) or by direct nanosynthesis, using micro- or nanoemulsions with nanoreactor compartments to perform polymerization. Polymer nanofibers (PNFs) can be produced via various techniques and the most commonly used approach is electrospinning, whereby a charged solution of a polymer when exposed to an opposite high electric field is pulled into long thin nanofibers. NSPs in general exhibit enhanced properties such as excellent structural and mechanical properties, making them promising candidates for some particular building applications. A variety of PNFs have been developed and used for noise and air pollution filtration. Moreover, PNFs can also be fabricated with phase change materials which are usually employed for thermal energy storage in construction industry. In this review, we will summarize the morphologies and nanosynthesis methods of NSPs, in particular, PNPs and PNFs. In addition, representative NSPs mainly used in construction are introduced for building applications.