Development of Anodic Alumina Membranes for Hemodialysis

In this paper, a novel large size (50x50 mm2) anodic porous alumina membrane specially used in hemodialysis process is developed. By using a two-step anodization fabrication method, a semi-permeable membrane with nano-sized pores is produced. Comparing with spongy style pores located on polymer membranes, this membrane has straight channel pores. And these pores are uniform in size. Experimental results in this paper also show that the relationship between membrane pore size and anodization voltage follows linear rule on the scale of several nano-meters. These intrinsic properties of the alumina membrane are highly desired in the process of hemodialysis since: 1) with straight channel pores, the adsorption amount of small molecules inside the membrane is much lower than that of spongy style pores; 2) the uniform pore size provides us a chance to avoid occurrence of protein leaking problem when using polymer membranes with spontaneous pore size; 3) the linearity property tells that the membrane pore size is controllable during quantitive fabrication.