Versatile light‐responsive organogels: Evaluation of their dye releasing and photoinitiation behaviors

Abstract

Light-responsive crosslinked structures were prepared by a straightforward quaternization strategy using chloride functional polystyrene copolymers and commercially available Michler's ketone with varying feed ratios. Resulting organogels demonstrated excellent solvent absorption and their swelling characteristics were altered by UV-light irradiation. According to scanning electron microscope images, UVilluminated samples showed an obvious photodecomposition, which enhanced their solvent uptake capacity with increase of UV exposure. Additionally, release behavior of eosin Y as a model compound was determined by UV-vis and fluorescence spectrometers. Achieved photoactive gels were also employed as the reusable heterogeneous initiators for photoinduced free-radical polymerization of methyl methacrylate.

Reversibly Softening and Stiffening Organogels Using a Wavelength-Controlled Disulfide-Diselenide Exchange

“…Typically, low molecular weight organogelators form networks through physical interactions, while polymeric organogelators form networks through chain entanglements or a combination of chemical and physical cross-linking . Organogels can be responsive to a number of external stimuli depending on the cross-linking chemistry, including light, , temperature, ,, redox agents, ,, and ultrasound . Light is a useful external trigger to induce responses in stimuli-responsive materials, as it can be applied locally without suffering from diffusion effects and be switched “on” and “off” easily .…”

Inherently UV Photodegradable Poly(methacrylate) Gels

“…The few reports available about photodegradable organogels suffer from long degradation times, require laborious synthesis of photolabile crosslinkers, or are too hydrophilic to serve in the applications mentioned above. [28][29][30][31][32] There has been no report about organogels that are readily synthesized, contain a large amount of hydrophobic solvent, and degrade fast under UV light. Thus, it is challenging to fabricate structured or patterned organogels.…”