Kang Fu,Yi Tian,Zongting Zhu,Shixin Fa,Qiuyu Zhang
Transparent omniphobic coatings have attracted extensive research over the past decade to meet growing application demands. Polydimethylsiloxane (PDMS)-based anti-fouling coatings have been widely reported to contribute a liquid-like surface for liquid repellency. The bulky PDMS chains usually make the surface greasy and energy-consuming. Fluorinated epoxy is expected to overcome the above drawbacks and contribute to excellent mechanical robustness. However, the reported fluorinated epoxy coatings are unsatisfactory due to severe phase separation, excessive fluorine content, poor self-healing and weatherability. In this work, a thiolactone-terminated fluorinated prepolymer (TTFP) was prepared through thiol-click chemistry. The thiolactone structure limited the phase separation and reacted efficiently with epoxy resin in a thiol-click manner after ring-opening. The flexible TTFP molecules had a strong surface migration ability, allowing the product coating to be liquid repellent with a low fluorine content and self-healed after damage. Therefore, a low-cost, eco-friendly, anti-ultraviolet, self-healed, highly transparent, mechanically robust and chemically resistant fluorinated epoxy coating was proposed. In addition to the excellent repellency to ink traces, fingerprints and thick paint, the coating with 5H pencil hardness could maintain omniphobic properties after 100 h of intensive UV irradiation or 12 h of alkali corrosion. Benefiting from the strong surface migration ability of flexible fluoroalkyl chains, the coating could recover its omniphobicity within 30 min of heating. The characterization results show the excellent comprehensive properties of the coating and its great potential for application in various scenarios.
Oil-in-oil emulsions are ideal systems for water-sensitive reactions such as polymerizations and catalytic reactions , which has received extensive attention in recent years. The application of oil-in-oil emulsions has been developed slowly due to the limited types of surfactants and complicated synthesis process. Herein, we proposed a simple method to prepare poly(amide-thioether)-based surfactant for oil-in-oil emulsions via taking advantage of single-pot multicomponent and click characters of thiolactone chemistry. Using a combination of alkyl amine and acrylamide thiolactone, the aminolysis of thiolctone occurred first, generating thiol group in-situ, and then the generated thiol group would sequentially react with the double bonds of acrylamide to form polythioether in the presence of amine. The hydrophobicity of the surfactant could be effectively adjusted by the chain length of the alkyl amine and thus this polymer could serve as a promising surfactant for oil-in-oil emulsion. Notably, the emulsion types could be switched by changing the chain length of the alkyl amine. In addition, the effects of surfactant loading, volume ratio of oil phases, oil types on the size and stability of oil-in-oil emulsions were further investigated. It was demonstrated that the oil-in-oil emulsion stabilized by poly(amide-thioether)s kept stable after more than five months. Besides, we preliminarily explored the application of the oil-in-oil emulsion to prepare closed cell foam and porous particles via photo-initiated thiol-ene polymerization. It is believed that this super-stable oil-in-oil emulsion could offer more possibilities for highly potential water-sensitive systems.
Abnormal activity level of human butyrylcholinesterase (BChE) was detected in patients with cardiovascular disease and neurodegenerative disorders, however, the specific role of BChE in the pathology of these diseases are not known yet. Homocysteine thiolactone (HTL) is a toxic thioester metabolite of homocysteine in conditions of hyperhomocysteinemia (HHcy). Experimental evidences suggest that HTL and resultant N-Hcy proteins that disrupt normal protein function, are associated with the pathology of HHcy-related complications such as cardiovascular diseases. Given the abundance of BChE in the blood and its esterase capacity, it is worthy to investigate the hydrolytic ability of BChE and its genetic polymorphism effects towards the endogenous toxic HTL in order to delineate its function in the complex disease network. In this study, human BChE and acetylcholinesterase (AChE) were examined for their ability in HTL hydrolysis, and BChE demonstrates higher catalytic efficiency than reported serum paraoxonase 1 (PON1). Furthermore, the catalytic mechanism uncovered by Quantum mechanics/Molecular mechanics (QM/MM) molecular dynamics (MD) method helps to understand and substantiate the function of BChE in HTL metabolism. Six frequent BChE nonsynonymous coding single nucleotide polymorphisms (SNPs) variants were recombinantly produced and their catalytic activity was assessed. Differential catalytic efficiency toward HTL was observed among these variants, suggesting their distinct metabolic capability in vivo . These findings highlight the potential protection role of BChE against HTL-induced toxicity, and pave a way for future investigation into BChE’s contribution in HTL metabolism and the possible correlation between specific BChE SNPs and susceptibility for developing HTL-associated diseases.
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