Porous Hollow Polylactic Acid Nano Fiber Preparation And Hydrophobic Oil-wet Performance Research

Based on the material of poly(lactic acid)(PLA)cortex,polyvinyl alcohol as the core layer material,was prepared by coaxial electrostatic spinning technology skin-core structure nanofibers,and the fiber membrane ultrasonic cleaning in distilled water,hollow nanofibers.According to the theory of infiltration,to improve the hydrophobic properties,will reduce material surface and the contact area of water,therefore,need to increase the fiber surface roughness.Preparation of selecting the volatile fast spinning DCM,and appropriate to join the DMF to improve electrical conductivity.In"breathing pattern"effect,appeared in the process of spinning fiber surface will be full of pore,the resulting porous hollow PLA nanofibers.For coaxial electrostatic spinning process parameters optimization,in order to get into a hole,shape good fiber obviously.In different concentration,spinning process parameters such as voltage,spinning distance,ratio of solvent,the preparation of nanometer fiber membrane,the fiber morphology is observed by scan electron microscope,and measured the fiber diameter of obtained under different process conditions.By comparison with fiber morphology,diameter,determine the optimal spinning process parameters.When 10%polylactic acid concentration,spinning voltage 18kv,spinning distance 20cm,DCM/DMF to speak,fiber morphology,surface is hole density uniform.Use of the performance of the polyvinyl alcohol soluble in water,the optimum shape fiber membrane with distilled water after drying,Transmission electron microscopy(sem)analysis,can clearly see the empty structure,and measured the average fiber diameter is 5.42 nm.Under the optimum parameters of the spinning preparation of polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core hollow fiber membrane,porous polylactic acid nano fiber membrane,and the three are powerful,tear,moisture permeability and other performance testing comparisons.The results show that the fracture strength of porous hollow PLA nanofibers membrane is 36.250cN,breaking elongation is 3.238 mm,lower than the same spinning under the condition of the preparation of polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core nanometer fiber membrane;Porous hollow PLA nanofibers membrane tear strength was 90.16 cN,below the same spinning under the condition of the preparation of polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core nanometer fiber membrane;Porous hollow PLA nanofibers membrane relative permeability is 33737.14 g/m~2d,below the polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core nano fiber membrane.Test results show that hydrophobic hydrophilic porous hollow polylactic acid nano fiber membrane on the water contact Angle is 136.9°,higher than the polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core nanometer fiber membrane;In peanut oil,silicone oil,the oil adsorption performance tests,porous hollow polylactic acid nano fiber membrane were 71.4 g/g oil absorption rate,108.8 g/g and 18.8 g/g,higher than the polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core nanometer fiber membrane;In the three kinds of oil performance tests of oil,porous hollow polylactic acid nano fiber membrane oil rate were 42.51%,37.89%,49.49%,were lower than that of polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core nano fiber membrane.Three kinds of fiber membrane put in the same amount of oil-water mixture,porous hollow polylactic acid nano fiber membrane extraction oil is higher than the polylactic acid nano fiber membrane,polylactic acid/poly(vinyl alcohol)sheath-core nano fiber membrane.Porous hollow polylactic acid nano fiber membrane absorption and oil drain 20times,record every oil absorption,the results showed that within 20 times,the porous hollow oil absorption of polylactic acid nano fiber membrane is not zero,shows that porous hollow polylactic acid nano fiber membrane has good repeatable usability.