Recently, I developed a new technology to fabricate porous fibers and fibrous membrane.
In short, poly(L lactic acid) (PLLA) was electrospun and collected as micro/nano fibers or fibrous membranes. At this stage, the electrospun PLLA fibers are solid fiber with smooth surface, like almost all other electrospun fibers.
Then, the collected PLLA fibers were treated by a special method and they became a porous structure with ultrahigh surface area. Meanwhile, they still keep the mechanical properties. The surface area of porous fibres is about 10-50 times higher than non-treated fibres.
For the porous PLLA fibers and fibrous membrane, they can find a wide range of applications in air/water filtration, separation, absorption, adsorption, tissue engineering, drug delivery, and so on.
Furthermore, if some functional materials, such as nano particles, carbon tubes, graphene, quantum dots, can be introduced into the porous PLLA fibers, PLLA fibrous membrane can server as a substrate to increase interactive interfaces between functional materials and their environments. Either it can improve the reaction efficiency or sensitivity, or reduce the consumption of functional materials which are quite expensive sometimes. The composite fibers can be used as anti-bacterial/cancer dressing, sensors, catalysis, and so on.
And using porous fibres as templates, some inorganic materials (TiO2, SiO2, ZnO, SiC) can be attached on the surface of porous fibres. After the samples are treated at high temperature, porous inorganic materails can be collected while the polymer templates are sacrificed.