Spatial control of flocculation via light

Abstract

A highly efficient photoinitiated flocculation system formed through the trapping of a photogenerated thiobenzaldehyde with polyethylenimine was developed. This photoresponsive system provides spatial and temporal control over flocculation processes and has been applied to heavy metal flocculation.

Triggered and Tunable Hydrogen Sulfide Release from Photogenerated Thiobenzaldehydes

“…[19] Recently,t rapping of thioaldehydes with amines led to applications in surface modificationb yB arner-Kowollik et al [20] and in flocculation by us. [21] This facile synthesis was performed in ao ne-pot manner,a nd the products were purified by crystallization from ethyl acetate (for X-ray structures, see Figure S1 of the Supporting Information). In this approach, benzylb romide and p-xylene dibromidew ere treated first with thiourea and then with bromoacetophenone under basic phase-transfer conditions to generate thiobenzaldehydep recursor 1 and 2 in 93 and 88 %y ield, respectively ( Figure 1a).…”

“…Recently, trapping of thioaldehydes with amines led to applications in surface modification by Barner‐Kowollik et al . and in flocculation by us . These highly reactive chemical intermediates quickly form imines in the presence of amines in a similar manner to aldehydes and amines, except that H 2 S is released as the byproduct instead of water.…”

“…In this work, we employed a photomasked thiobenzaldyde as a versatile means of H 2 S release on light triggering and subsequent trapping with an amine. In this approach, benzyl bromide and p ‐xylene dibromide were treated first with thiourea and then with bromoacetophenone under basic phase‐transfer conditions to generate thiobenzaldehyde precursor 1 and 2 in 93 and 88 % yield, respectively (Figure a) . This facile synthesis was performed in a one‐pot manner, and the products were purified by crystallization from ethyl acetate (for X‐ray structures, see Figure S1 of the Supporting Information).…”

Effect of heat treatment on the performance of 3D printed thermoplastic polyurethane flexible substrates

“…In the first stretch cycle, some weak physical crosslinking points and covalent bonds are destroyed, resulting in permanent deformation and the rearrange of molecular chains along the stretching direction. 27 As a result, in the subsequent stretching cycles, the deformation recovery rate increases with the number of cycles and tends to be stable.…”