Polymeric Photoresist Nanoparticles: Light‐Induced Degradation of Hydrophobic Polymers in Aqueous Dispersion

Abstract

Nanoparticles consisting of a photoreactive polymer able to radically switch its hydrophobicity are successfully prepared by miniemulsion polymerization. Irradiation with UV light causes degradation of the particles where at complete dissolution is achieved by changing the initial hydrophobic photoresist polymer into hydrophilic poly(methacrylic acid). Incorporation of the fluorescence-sensitive Nile red serves as a solvatochromic probe to study the particle degradation. Diffusion of either Nile red out from or water into the former hard spherical nanoparticles is studied and not only renders the described material an ideal system for applications, where in situ dissolution of nanoparticles may be needed, but also bears the additional advantage of performing controlled burst release.

Anion Responsive Imidazolium‐Based Polymers

“…Inverse miniemulsion suspension polymerization65 was used to prepare particles from VC 4 C 1 ImBr and the cross‐linker bis(VIm)C 4 Br 2 66. The monomers were dissolved in water along with thermal initiator (V50) and then emulsified in hexane using Span 80 as dispersing aid.…”

Highly Reliable Silver Nanowire Transparent Electrode Employing Selectively Patterned Barrier Shaped by Self-Masked Photolithography

“…The applied photoresist is composed of a novolac resin and an organic photosensitizer, both of them are hydrophobic organics and hardly soluble in water. [49][50][51] The hydrophobic barrier films are often applied to prevent the degradation of metals susceptive to high humidity. 52,53 For AgNWs, the corrosion was accelerated by high humidity, 26 especially cooperated with high temperature.…”

Tuning drug release in polyester thin films: terminal end-groups determine specific rates of additive-free controlled drug release

“…For example, several technologies used by the photolithography industry allow instantaneous formation of carboxylic acid groups through the conversion of ortho-nitrobenzyl esters. 29 Pulses of light create more carboxylic acid end-groups and would allow a gradual increase in drug delivery as needed. Similar formation of acidic end-groups can be envisioned by other 'SMART' triggered events (for example, ultrasound, electrical signal, light, temperature 30 ) for switchable hydrophobic/hydrophilic surfaces.…”