A Catalytic and Positively Thermosensitive Molecularly Imprinted Polymer

Abstract

A catalytic and positively thermosensitive molecularly imprinted polymer is reported. This unique imprinted polymer was composed of 4‐nitrophenyl phosphate‐imprinted networks that exhibited a thermosensitive interpolymer interaction between poly(2‐trifluoromethylacrylic acid) (PTFMA) and poly(1‐vinylimidazole) (PVI), which contains catalytically active sites. At a relatively low temperature (such as 20 °C), this imprinted polymer did not demonstrate significant catalytic activity for the hydrolysis of 4‐nitrophenyl acetate due to the interpolymer complexation between PVI and PTFMA, which blocked access to the active sites of PVI and caused shrinking of the polymer. Conversely, at higher temperatures (such as 40 °C), this polymer showed significant catalytic activity resulting from the dissociation of the interpolymer complexes between PVI and PTFMA, which facilitated access to the active sites of PVI and inflated the polymer. Unlike previously reported poly(N‐isopropylacrylamide)‐based molecularly imprinted polymers, which demonstrated decreased molecular recognition and catalytic activity with increased temperatures, i.e., negatively thermosensitive molecular recognition and catalysis abilities, this imprinted polymer exploits the unique interpolymer interaction between PVI and PTFMA, enabling the reversed thermal responsiveness.

Molecularly imprinted polymers as biomimetic catalysts

“…Comparison with an imprinted polymer prepared in the Molecular self-assembly between the 1-vinylimidazole monomer and the phosphate template same way but without the N-isopropylacrylamide monomer shows that at low temperatures the thermoresponsive polymer has significant catalytic activity, whereas at high temperature its activity is similar to that of the nonimprinted matrix. The same group has developed the system further [32] by preparing a positively thermosensitive molecularly imprinted polymer, using 1-vinylimidazole and 2-trifluoromethylacrylic acid as the functional monomers and divinylbenzene as the crosslinker, using 4-nitrophenyl phosphate as the template (Fig. 6).…”

Molecularly Imprinted Polymers for Catalysis and Synthesis

“…The following year Li et al [47] presented another thermosensitive MIPs-based catalyst using the hydrolysis of 4-nitrophenyl acetate (NPA) as the model reaction. The idea behind the new catalyst was similar to what had already been published.…”

Composites of Silica and Molecularly Imprinted Polymers for Degradation of Sulfadiazine

“…It can be observed that MIPs-I exhibited an absorbance decrease upon heating solutions from 25 to 60°C and the inset in Figure 7 indicated the LCST of MIPs-I was 36.1°C, which was higher than that of pure PNIPAm. 14 According to previous studies, the introduction of hydrophobic monomer as the cross-linking agent into PNIPAm chains could slightly change the LCST of PNIPAm. 36 In this work, the crosslinking monomer (EGDMA), which is hydrophobic, making the LCST of MIPs-I litter higher that that of pure PNIPAm.…”