Photocatalyst-Incorporated Cross-Linked Porous Polymer Networks

Abstract

The utilization of sunlight to conduct chemistry has been on a stark rise in the era of sustainability. A similar trend is observed in polymer science, mainly to initiate polymerization and modify polymer materials, but mostly relying on the utilization of soluble initiator/activator molecules. Semiconductors, on the other hand, grant a platform for "photoredox" induced chemical pathways, so that reductive and oxidative reactions (as well as radical formation) can be tailored according to band positions. Despite their utilization as dispersed or dissolved phases, immobilization of semiconductors on macroscale solid surfaces is attractive to entail scale-up options. In this Review, semiconductors incorporated in cross-linked porous polymer networks will be summarized both from synthesis and application perspectives.

Liquid–Liquid-Printed Graphitic Carbon Nitride-Embedded Porous Poly(ionic liquid) Beads as Highly Active Reusable Heterogenous Photocatalysts

“…PIL-only beads possess many defects and appear as a soft hydrogel-like material (Figure a), whereas addition of g-CN generates a more ordered and porous structure with improved rigidity (Figure b). It is well-known that g-CN can act as polymerization loci under light irradiation, contributing to additional cross-linking, and this improved cross-linking could improve the rigidity of the formed bead. , …”

“…It is well-known that g-CN can act as polymerization loci under light irradiation, contributing to additional cross-linking, and this improved cross-linking could improve the rigidity of the formed bead. 36,37 Figure 6d shows that although the surfaces of g-CN/PIL beads appear smooth at first glance, the beads possess a high degree of porosity which was not observed in PIL-only beads as seen in Figure 6c, where a smooth surface and very large holes are seen on the bead. This shows the effect of heptane as an antisolvent.…”

“…Compared to the outer shell, crystallite domains appear to be more pronounced in the inner porous layer, which is a key point to generate photocatalytic systems. 36 Figure S4 elucidates different morphologies on so-formed beads.…”

Emerging Concepts in Iodine Transfer Polymerization

“…Heterophase polymerizations to architect colloidal objects can take special profit from ITP, using some adaptions to the multiphase character of reactant distribution and growth processes. [ 44 ] Microsuspension polymerization of methyl acrylate via ITP using CHI 3 as CTA was demonstrated. [ 45 ] The reaction setup was based on vortex stirring organic phase (consisting of methyl acrylate, benzoyl peroxide as initiator, and CHI 3 with altered ratios) in aqueous poly(vinyl alcohol) solution, where polymerization was carried out at 80 °C in 6 h. Controlled (with Đ : 1.5) living polymerization with high conversion (up to 92%, M w 90 000 g mol −1 ) was obtained for micrometer‐sized polymer particles, while no submicrometer‐sized byproducts were observed.…”

Polymers as Aerospace Structural Components: How to Reach Sustainability?

“…Macromolecules have existed on Earth for as long as natural polymers, however, massive progress in synthetic polymers in the last 100 years led to a large library of polymer materials which are employed almost everywhere in daily life. [ 1,2 ] When the performance of a polymer is not satisfactory, blends and composites can be structured in order to introduce/enhance many physical values such as mechanics, [ 3 ] electrical conductivity, [ 4 ] photoactivity, [ 5,6 ] thermal resistance, [ 7 ] and so on. Polymer composites can have varying architectures including particles, [ 8 ] whiskers, [ 9 ] sheets, [ 10 ] short fibers, [ 11 ] continuous fibers, [ 12 ] and laminates [ 13 ] from nano‐ to macroscale using organic/inorganic materials.…”