Mechanism Of PVP Electrospinning

Electrospinning is one of the most important and fundamental approaches to producing ultrafine fibers,even nanofibers.Because of their high surface area,distinctive netlike structure, high microporosity and the bright future with a broad range of applications in widely different areas,electrospun nanofibers are increasingly becoming very popular in nanotechnology field and industry.Electrospinning,determined by many parameters,is a very complex process.To develop and apply electrospinning technology,it is essential to study how various parameters accounting for the morphology and property of the nanofibers.The influence of solution system in electrospinning is investigated firstly.The constitution of solvent is important in determining the morphology of the nanofibers.A mixture of deionized water and absolute alcohol was used as solvent.The experimental results showed that the electrospinability of the solution and morphology of the nanofibers were improved when the weight ratio of absolute alcohol was high.To study the influence of surface tension in electrospinning,a representative non-ionic surfactant was added to an electrospun poly(vinyl pyrrolidone) polymer solution.A dramatic reduction in surface tension,which leading to the reduction of the diameter of nanofibers,and the improvement of electrospinability of the solution were observed.A very simple theoretical prediction of the average diameter of the nanofibers under different surfactant concentrations was given.An inorganic salt was added to PVP polymer solution to study the effect of conductance on electrospinning.The experimental results showed that,in case of Wt%≤0.6%(Wt%is the concentration of inorganic salt),the diameter of the nanofibers decreased with increasing concentration of inorganic salt.A very simple theoretical prediction was given to explain the relationship between the average diameter of the nanofibers and the conductance of the solution.Carboxymethyl chitosan can be applied to many fields,such as medicine,chemical Engineering and environmental protection,and its nanofibers have a bright future with a broad range of applications in different areas.However,the carboxymethyl chitosan nanofibers can not be manufactured easily by electrospinning.In this paper,a mixture of carboxymethyl chitosan and PVP was used as solute to electrospin and the nanofibers of carboxymethyl chitosan and PVP were produced.To study the functions of various parameters in electrospinning,the orthogonal design method was adopted in the experiments.The experimental results showed that applied voltage was the significant factor in electrospinning.