Inherently UV Photodegradable Poly(methacrylate) Gels

Abstract

Organogels (hydrophobic polymer gels) are soft materials based on polymeric networks swollen in organic solvents. They are hydrophobic and possess a high content of solvent and low surface adhesion, rendering them interesting in applications such as encapsulants, drug delivery, actuators, slippery surfaces (self-cleaning, anti-waxing, anti-bacterial), or for oil-water separation. To design functional organogels, strategies to control their shape and surface structure are required. Herein, the inherent UV photodegradability of poly(methacrylate) organogels is reported. No additional photosensitizers are required to efficiently degrade organogels (d ≈ 1 mm) on the minute scale. A low UV absorbance and a high swelling ability of the solvent infusing the organogel are found to be beneficial for fast photodegradation, which is expected to be transferrable to other gel photochemistry. Organogel arrays, films, and structured organogel surfaces are prepared, and their extraction ability and slippery properties are examined. Films of inherently photodegradable organogels on copper circuit boards serve as the first ever positive gel photoresist. Spatially photodegraded organogel films protect or reveal copper surfaces against an etchant (FeCl 3 aq. ).

Patterning meets gels: Advances in engineering functional gels at micro/nanoscales for soft devices

“…Adapted with permission. 70 Copyright 2021 John Wiley and Sons. (E) Schematic representation of "writing" line structures by nanochannel delivery of basic inks onto a supramolecular hydrogel film to induce local degradation and the resultant AFM images.…”

“…The multiscale structures or microstructured channels on hydrogel/organogel surfaces could guide the transport of various polar and nonploar liquids as well, as shown in Figure 7D. 65,70 Kong group also employed laser engraving to fabricate microfluidic channels on a tough double-network hydrogel and embedded liquid metal electrodes inside for bioelectronic monitoring. 23 3Dprinted microchannel network within the hydrogel also allowed rapid capillary-driven water transport for efficient collection.…”

“…Furthermore, patterning organogels was also achieved by designing polymethacrylate networks crosslinked with poly(propylene) glycol dimethacrylate (PPGDMA) and utilizing 1‐nonanol or 1‐butanol as the filling solvent (Figure 7C). 70 The selected solvent was critical to ensure both UV transmission and network swelling for successful photodegradation. As a result, slippery microchannels could be generated on the organogel surface after patterning, which permitted fast liquid sliding and microfluidic applications (Figure 7D).…”

“…(D) The application of patterned organogel as slippery microchannels. Adapted with permission 70 . Copyright 2021 John Wiley and Sons.…”

Transient Photodegradability of Photostable Gel Induced by Simultaneous Treatment with Acid and UV–Light for Phototuning of Optically Functional Materials

“…Photodegradable materials enable the tuning of material shapes and properties on demand with a high spatiotemporal resolution of light, and have gained importance in various applications, [1][2][3] including photoresists, [4][5][6] drug-delivery systems, [7][8][9][10][11] and tunable cell culture platforms. [12][13][14][15] In general, they are integrated with photocleavable moieties in polymeric networks as a cross-linker.…”