Preparation and Characterization of Microporous Hollow Fiber Membranes Containing Hydrotalcite as an Inorganic Adsorbent

Abstract

Polyethersulfone (PES) hollow fiber membranes containing hydrotalcite as an adsorbent were prepared by the nonsolvent induced phase separation method. In the membrane preparation, the weight ratios of PES and hydrotalcite were varied from 3:1 to 3:2 and 3:4. It was found that an effective cavity was formed around the hydrotalcite contained in the membrane. This is because the compatibility between hydrophobic PES and hydrophilic hydrotalcite is poor. The existence of a cavity in the membrane is useful for adsorption because the effective surface area of the adsorbent included in the membrane is large. On the contrary, in the PES membrane containing activated carbon, such a cavity was not observed and the PES was in close contact with the activated carbon. Both PES and activated carbon are hydrophobic and thus high compatibility between them prevented cavity formation. The adsorption ability of phosphate on the hydrotalcite contained in the membrane was investigated. 30~40 % of the original adsorption ability of the hydrotalcite particle was retained.