Thermoresponsive cryogels of poly(2-hydroxyethyl methacrylate-co-N-isopropyl acrylamide) (P(HEMA-co-NIPAM)): fabrication, characterization and water sorption study

Tominaga T, Moretti Bonadio TG, P. da Silveira N, C. Leite D. A Study on the Behavior of Smart Starch-co-poly(N-isopropylacrylamide) Hybrid Microgels for Encapsulation of Methylene Blue

Hybrid microgels made from starch nanoparticles (SNPs) and poly(N-isopropylacrylamide) p(NIPAM) were used as promising hosts for the methylene blue (MB) dye. In this paper, these thermoresponsive microgels were characterized by dynamic light scattering (DLS), zeta potential measurements (ZP), and scanning electron microscopy (SEM) and evaluated as carriers for skin-targeted drug delivery. The hybrid microgel-MB systems in PBS solution were also studied by UV-vis spectroscopy and DLS, revealing discernible differences in spectral intensity and absorption shifts compared to microgels devoid of MB. This underscores the successful integration of methylene blue within the SNPs-co-p(NIPAM) microgels, signifying their potential as efficacious drug delivery vehicles.

The specific biopanning of single-domain antibody against haptens based on a functionalized cryogel

Phage display technology is commonly applied for high-throughput screening of single-domain antibodies (sdAbs), and the problem of non-specific adsorption caused by carrier proteins seriously affects the biopanning of single-domain antibodies specific to haptens. In this paper, enrofloxacin (ENR)-functionalized cryogels were prepared by the ethylenediamine (EDA) and carbodiimide methods for application in the biopanning of ENR-specific phages. To improve the efficiency of biopanning, double blocking, a wash solution flow rate of 1 mL/min, and phage pre-incubation were applied to the biopanning process through single-factor experiments. Results of flat colony counting showed that the phage output of AG-ENR cryogels was 15 times higher than that of AG cryogels for the same input amount. And seven complete sequences of ENR-specific shark sdAbs were obtained by monoclonal phage ELISA and sequence alignment. All these results indicate that functionalized cryogels could be used as a novel and efficient method for phage biopanning for single-domain antibodies to haptens.

Photoluminescent Polymer Aerogels with R, G and B Emission

In this work, three new polymer aerogels based on 2-hydroxy ethyl methacrylate (HEMA) complexes with Eu(III), Tb(III) and La(III) are prepared and investigated. The polymer aerogels present strong photoluminescence with emissions located in the red, green and blue regions of the visible spectrum. Depending on the water content used during the preparation path, the consistency of the photoluminescent aerogels varies from rigid, regularly shaped monoliths to a flexible, fibrous material with very low density. The morpho-structural investigation was performed by FT-IR, XPS and SEM. Thermal behavior was also evaluated, while steady-state fluorescence spectroscopy, absolute PLQY and lifetime were used for the investigation of their luminescent properties. The impressive photoluminescent emission located in the red, green and blue areas of the visible spectrum is preserved irrespective of the selected porosity. Their photo-emissive properties, tunable porosity and the convenience of the preparation path could be some arguments for applications as photonic conversion mediums in special-purpose optoelectronic devices or sensors.

Preparation of the Temperature-Responsive Superhydrophobic Paper with High Stability

In this paper, a method for preparing a high-stability superhydrophobic paper with temperature-induced wettability transition is proposed. First, a temperature-responsive superhydrophobic triblock polymer PHFMA-PTSPM-PNIPAAm was prepared by one-step polymerization of TSPM, HFMA, and NIPAAm in a mass ratio of 0.3:0.3:0.3, then a superhydrophobic paper with a good temperature response was successfully prepared by grafting amino-modified SiO₂ with the polymer to modify the surface of the paper. A further study found that when the mass ratio of amino-modified SiO₂ to polymer is 0.2, the coating has good superhydrophobicity and transparency. What is more, the prepared modified paper is in a superhydrophobic state when the temperature is higher than 32 °C, and is in a superhydrophilic state when it is lower than 32 °C, which can realize free conversion between superhydrophobic and superhydrophilic states. In addition, the superhydrophobic paper prepared by this method not only has high oil-water separation efficiency, and the superhydrophobic coating shows good stability and transparency, but also has low requirements of environmental conditions for preparation, relatively simple preparation process, and strong repeatability, and it has a very broad application prospect.

Preparation of Fluorine-Free Superhydrophobic Paper with Dual-Response of Temperature and pH

Although various superhydrophobic materials have been manufactured and effectively used for oil–water separation, it is still highly desirable to explore materials which are eco-friendly, low-cost, and multifunctional. In this paper, a stable copolymer solution was prepared from the fluorine-free superhydrophobic copolymer with dual-responsiveness of temperature and pH. The functional superhydrophobic paper was prepared by immersing paper in copolymer solution by the dip-coating method. The surface element and structure analysis of the prepared superhydrophobic paper shows that the dual-responsive copolymer adheres successfully to the surface of the paper without destroying the fiber structure of the paper. At pH ≥ 7 and T > 25 °C, the paper has a good superhydrophobic performance, while under the conditions of pH < 7 and T < 25 °C, the paper comes into a hydrophilic state. Therefore, the dual-responsive superhydrophobic paper is more likely to adapt to the complicated oil-water separation environment than the single-response.

Improved Dimensional Stability and Mold Resistance of Bamboo via In Situ Growth of Poly(Hydroxyethyl Methacrylate-N-Isopropyl Acrylamide)

Bamboo is a natural and renewable building material but its application has been limited due to the low dimensional stability and poor durability against mold. In this study, monomers of hydroxyethyl methacrylate (HEMA) and N-isopropyl acrylamide (NIPAM) were impregnated in bamboo to facilitate the in situ growth of poly-HEMA and NIPAM (PHN) copolymer. Prior to that, the effects of different reaction conditions, including the molar ratio of HEMA to NIPAM and their concentrations, the amount of initiator (ammonium persulfate, APS) and crosslinking agents (N,N′-Methylenebisacrylamide (MBA), and glutaric dialdehyde (GA)) on the swelling capacity of PHN were optimized. The formation of PHN was confirmed by using Fourier transform infrared spectroscopy and thermogravimetric analysis, which shows the characteristics peaks of both HEMA and NIPAM, and increased pyrolysis and glass transition temperatures, respectively. After impregnation of PHN pre-polymerization formulation to bamboo, it was observed that PHN filled most of the pits in the bamboo cell wall and formed a tight network. Moreover, the dimensional stability of PHN treated bamboo was significantly improved with an anti-swelling efficiency of 49.4% and 41.7%, respectively, after wetting–drying and soaking–drying cycles. A mold infection rate of 13.5% was observed in PHN-treated bamboo as compared to a 100% infected control group after a 30-day mold resistance test. Combined results indicate that in situ polymerization of HEMA and NIPAM in bamboo is a promising method to develop exterior used bamboo products with enhanced dimensional stability and mold resistance.