Fabrication of porous polylactic acid films assisted by dip-coating and template leaching techniques

A new simple method was developed to fabricate porous polylactic acid (PLA) films coated directly on substrates. The PLA films with a controllable thickness were realized using a dip-coating technique. The pore structure of the resulting porous PLA films was tailored by utilizing phase inversion process and template leaching techniques. The experimental results show that the resulting PLA films became thicker when using the coating solution with a higher viscosity or applying a faster withdrawal speed. The porous structures (pore size and void density) of the resulting PLA films are significantly influenced by the polymer concentration, the nonsolvents, and the addition of poly(ethylene glycol) templates. The analyses of solubility parameters was utilized to explain the porous structures of the resulting PLA films in details.