EXPERIMENTAL STUDY OF NANOPOROUS CERAMIC TUBE IN POTENTIAL APPLICATION IN HEMODIALYSIS

Abstract

The self-organized nanoporous ceramic tubes offer considerable advantages over current hemodialysis membranes such as controllable pore size, uniform pore distribution, high porosity, chemical and thermal durability. The objective of this study is to fabricate and characterize nanoporous ceramic tubes and to test its hydraulic conductivity for potential use in hemodialysis. The tubular alumina membranes were anodized from an aluminum alloy in 2.7% oxalic acid at 30 V and 40 V for about 2 to 3 days. Anodization from interior to exterior made the tube strong, thereby facilitating easy mechanical handling. The membranes were imaged using a high resolution FEI SEM and characterized by using an NIH imaging software. Mini-module dialyzers of different tube lengths were made and their hydraulic conductivities were tested. The results showed that the pore size and porosity were in the range of 15.61±7.63 to 42.28±23.72 nm, and 15.77±1.86% to 49.13±4.43%, respectively, and the pore size and porosity change linearly with anodization time. The average hydraulic conductivity for the 3 cm, 6 cm and 9 cm length ceramic tubes was 1.025±0.29 x 10-15 m2Pa-1s-1, with a membrane thickness of 69 μm. This value could be increased by increasing the porosity on the outside surface of the tube using longer etching time. By using anodic alumina technology, nanoporous ceramic tubes with feature sizes approximately 15 to 45 nm can be reliably produced in quantity. These features make the nanoporous ceramic tube a potential application in hemodialysis.