Preparation of thermoresponsive hydrogels via polymerizable deep eutectic monomer solvents

Abstract

We report the preparation of thermoresponsive hydrogels via free-radical polymerization and crosslinking of NIPAM based deep eutectic monomer solvents (DEMs).

Greener, Faster, Stronger: The Benefits of Deep Eutectic Solvents in Polymer and Materials Science

“…Our group [ 104 ] recently reported the preparation of cross-linked thermoresponsive poly( N -isopropylacrylamide- co - N,N’ -methylenebisacrylamide) hydrogels prepared directly from polymerizable eutectics based on N -isopropylacrylamide (NIPAM) and various choline salts ( Figure 7 ). NIPAM-based eutectics with a 3:1 composition were shown to possess low melting points of 39 °C and 15 °C, respectively, when prepared with ChCl and acetylcholine chloride (AcChCl), respectively, which were subsequently polymerized and cross-linked via the addition of potassium persulfate and BIS, respectively.…”

“…Thermoresponsive hydrogels via 3:1 N-isopropylacrylamide (NIPAM):ChCl/AcChCl polymerizable eutectics.The resulting hydrogels exhibited a significant increase in shear modulus compared to equivalent gels prepared in water. Adapted from Ref[104] with permission from The Royal Society of Chemistry, copyright 2020.…”

Transforming nature into the next generation of bio-based flexible devices: New avenues using deep eutectic systems

“…47,48 The pioneering work with acrylic acid functioning as an HBD to form a DES monomer with ChCl able to produce poly(acrylic acid) by free-radical polymerization has triggered the development of a series of DES monomers made of acrylates. 29 Some examples are methacrylic acid, 30 acrylamide, 49 N-isopropylacrylamide, 50,51 and itaconic acid. 52 By adding multifunctional monomers (e.g., crosslinkers) and tuning the DES monomers structure (e.g., its alkyl chain length and pendant groups), 27,49,53,54 the polymer's mechanical properties can be tailored, from glassy materials to flexible and stretchable polymer composites that exhibit electrical conductivity in the range of 10 À3 to 3.2 mS cm À1 (see Table 1 and Figure 1).…”

“…1 Switching between hydrophobic and hydrophilic surfaces to control signaling input in response to biological events could be an important way of controlling the devices on/off to, for instance, control drug delivery close to the lower critical solution temperature of thermoresponsive polymers and body temperature. Combination of the well-known CO 2 and thermo stimuli responsive polymers, e.g., amines, amidines, and guanidines-based polymers and poly(N-isopropylacrylamide), 51,183 with the recently discovered DESs that respond also to temperature 184 and CO 2 , 185 are some directions to follow.…”

Synthesis of Stimuli-Responsive, Deep Eutectic Solvent-Based Polymer Thermosets for Debondable Adhesives

“…Of note are polymerizable groups that are covalently tethered onto the small-molecule components for DESs since functionalized DESs offer a versatile platform for the synthesis of stimuli-responsive materials via self-polymerization. Such polymeric materials demonstrate characteristic properties of elasticity, conductivity, and transparency while they are further enhanced by self-healing properties, − controllable shape or strengths, , and adaptabilities to 3D printing. , In particular, the viscoelastic materials support the formation of conductive elastomers that are capable of reversible sensing for strain change or providing a flexible platform for optoelectronic devices; − besides, they are also applicable to molecular imprinting and the development of advanced electrolytes. − The majority of the polymeric materials have been prepared by using traditional DESs that are composed of nonfunctional or partially functional species and via simple radical polymerization. However, given the broad libraries of functional groups that participate in hydrogen bonds and polymerization mechanisms, the molecular design of monomeric building blocks can be manipulated to not only alter macroscopic properties of the resultant polymerized DESs but also give rise to stimuli-responsive materials that are compatible with sustainable applications.…”