Titania nanowires coated PEI/P25 membranes for photocatalytic and ultrafiltration applications

Abstract

Bulk compositing and surface functionalization are combined to achieve a polymeric membrane that is covered with TiO2 nanowires, which possesses multi-functions of photodegradation, separation and self-cleaning.

Critical Issues and Guidelines to Improve the Performance of Photocatalytic Polymeric Membranes

“…Table 3 shows different coating techniques to prepare thin-film photocatalytic membranes, including vacuum deposition also called vacuum filtration [69][70][71][72][73][74][75], filtration [76,77], immersion [78][79][80][81][82][83][84][85], electrospraying [86], co-electrospinning [87], hot-press deposition [88], and sputtering followed by anodization [89]. Being immersion and vacuum deposition, the techniques mostly used.…”

“…As it can be observed in Tables 1-3, the photocatalytic membranes prepared so far were mostly synthesized using semiconductor materials such as TiO 2 [15,16,18,[23][24][25][26]28,29,36,47,[52][53][54][55][56][57][58][59][60]64,65,68,83,84,86,88,89], ZnO [44,45,48,63,67], g-C 3 N 4 [34,40,71], and Fe 2 O 3 [75]. Most of them are metal oxides such as TiO 2 , ZnO, and Fe 2 O 3 .…”

“…The influence on membrane morphology will be further discussed in the section covering the membrane synthesis methods of the present review. Some authors have observed a so-called superhydrophilicity of polyvinylidene fluoride (PVDF) [15,18,59], polysulfone (PSF) [28,29], polyethersulfone (PES) [97], PES-F-COOH [43], and polyetherimide (PEI) [83] membranes that incorporate TiO 2 . Superhydrophilicity is defined as an intrinsic property of TiO 2 surface that generates a significant increase in water flux under UV or sunlight conditions [15,16,59,98].…”

“…Moreover, it provides good mechanical properties, particularly its flexibility. PEI, whose chemical formula is (C 37 H 24 O 6 N 2 )n [83], PA [85], and PA6 also known as nylon 6 [65] are other nitrogen-containing polymers that have been attempted to a lesser extent for preparation of photocatalytic membranes.…”

A critical review on nanomaterials membrane bioreactor (NMs-MBR) for wastewater treatment

“…Nanowires offer higher aspect ratio (length to diameter/width ratio) of over 1000 compared to other onedimensional nanomaterials such as nanofibers with an aspect ratio of 3-5; this makes nanowires useful in environmental applications 141 . The presence of NWs on a membrane surface enhanced pollutant removal and compared to conventional membranes, NW membranes exhibit flexible, uniform and multifunctional activity and could be used to remove other foulants such as microorganisms and trace organics 142,143 .…”