Layer-by-layer TiO2 Nanocoating on Electrospun Polymers for Increased Photocatalysis Efficiency

Applications

This technique can be used on complex substrates to make protective clothing systems, sensors, and reactive filters. The use of electrospun fiber mats as substrate provides a robust material with high surface area and mechanical integrity that is ideal for such applications. 

Problem Addressed

Promoting photocatalytic degradation of toxic chemicals, including chemical warfare agents,  by using TiO2 to attain high reaction efficiency with natural sunlight, immobilization on the supporting materials, and sufficient activity without degradation of the supporting materials is still a challenging task to accomplish. This invention creates a coating that will preserve the thermal and chemical properties of the polymer fibers, as well as their high surface area  and resistance against UV degradation. 

Technology

This invention prepares photoreactive TiO2 nanoparticle coatings through layer-by-layer (LBL) assembly with polyhedral oligomeric silsesquioxane (POSS) molecules on polymer electrospun fibers. In order to increase the efficiency of the TiO2 photocatalysis, fibers with a high surface to volume ratio are electrospun from various polymer solutions and subsequently coated with TiO2 nanoparticles using LBL assembly. Using the electrospinning technique, many different polymers can be formed to create the high specific area substrate, and the flexibility of the polymer fiber is retained after TiO2 LBL nanoparticle coating. Assembly of the TiO2 nanoparticle coating with cationic POSS molecules is used to protect substrates under UV photocatalysis condition , and thus, mitigate concerns about the degradation of the substrate under severe photocatalysis conditions by increasing the number of inert coating layers using the  TiO2 / POSS NH3+ electrolyte nanoparticle pair. 

Advantages

  • High temperature calcination is unnecessary
  • Coating can be applied to a variety of polymeric or other substrates, including those with high specific surface area, without compromising the properties of the substrate
  • Increases efficiency of TiO2 photocatalysis