Electrostatic Repulsive Features of Free-Standing Titanium Dioxide Nanotube-Based Membranes in Biofiltration Applications

Abstract

This study presents the electrostatic repulsive features of electrochemically fabricated titanium dioxide nanotube (NT)-based membranes with different surface nanomorphologies in cross-flow biofiltration applications while maintaining a creatinine clearance above 90%. Although membranes exhibit antifouling behavior, their blood protein rejection can still be improved. Due to the electrostatically negative charge of the hexafluorotitanate moiety, the fabricated biocompatible, superhydrophilic, free-standing, and amorphous ceramic nanomembranes showed that about 20% of negatively charged 66 kDa blood albumin was rejected by the membrane with ∼100 nm pores. As the nanomorphology of the membrane was shifted from NTs to nanowires by varying fabrication parameters, pure water flux and bovine serum albumin (BSA) rejection performance were reduced, and the membrane did not lose its antifouling behavior. Herein, nanomembranes with different surface nanomorphologies were fabricated by a multi-step anodic oxidation process and characterized by scanning electron microscopy, atomic force microscopy, water contact angle analysis, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The membrane performance of samples was measured in 3D printed polyethylene terephthalate glycol flow cells replicating implantable artificial kidney models to determine their blood toxin removal and protein loss features. In collected urine mimicking samples, creatinine clearances and BSA rejections were measured by the spectrophotometric Jaffe method and high-performance liquid chromatography.

Preparation and Upscaling of Zeolite@TiO2 Core‐shell for the Removal of Pb(II) and Methylene Blue Dye from Wastewater

“…Electrostatic interaction between SDS and TiO 2 is caused by the presence of sulfate anion present in SDS. Further, the positive charge on Ti−OH + is attracted to the sulfate anion to form an electric double layer [39] . Subsequent layers were coated on the single‐layer nano‐titania over zeolite that acts as a seeded core layer which facilitates further coating of the TiO 2 in multiple layers [40] .…”

“…Further, the positive charge on TiÀ OH + is attracted to the sulfate anion to form an electric double layer. [39] Subsequent layers were coated on the single-layer nano-titania over zeolite that acts as a seeded core layer which facilitates further coating of the TiO 2 in multiple layers. [40] The particles were coated twice and thrice to form Zeolite@TiO 2 triple-coated composite particles.…”