Electrospun bead-in-string fibrous membrane prepared from polysilsesquioxane-immobilising poly(lactic acid) with low filtration resistance for air filtration

This paper first investigated the optimum conditions for the preparation of electrospun bead-in-string fibrous membrane based on polysilsesquioxane (PSQ)-immobilising poly(lactic acid) (PLA-PSQ). Then, the fibrous membrane was used for air filtration. It is found that the immobilisation of PSQ to PLA makes more and well-distributed bead-in-string strutures form in the fibres, which makes some properties of fibrous membranes improve. First, the beads in string make fibres with bigger and more even pores, and the broadened pores decrease the pressure drop across the PLA-PSQ membrane after air filtration by about 43% compared to that of the PLA membrane at a separation efficiency of 100%. Then, the evenly distributed beads in the fibres make the pore distribution of the fibres more even, which prevents many more dust particles from passing through the pores at a lower pressure and inhibits the aggregation of dust particles during air filtration. Furthermore, the immobilisation of PSQ to PLA decreases the loss of PSQ, and the PLA-PSQ fibre shows better hydrolytic resistance.