Humidity-responsive polymer films are promising for visual moisture sensing and soft actuation, yet conventional systems mainly rely on bulk matrix swelling and lack well-defined micro/nanostructures for rapid water molecule transport, making fast, reversible, and readable deformation difficult to achieve. Here, we introduce vertically aligned subnanochannel arrays into a smectic liquid crystal polymer film through alkaline treatment of a hydrogen-bonded network. The resulting carboxylate-rich nanochannels provide continuous pathways for water vapor adsorption and transport while maintaining the ordered smectic polymer framework. Upon exposure to moisture, water molecules enter the negatively charged subnanochannels and induce anisotropic swelling, leading to rapid and reversible bending. The film serves as a visual humidity indicator, showing a bending angle of approximately 79° at 80% relative humidity within 7 s and stable cycling over 100 cycles. In addition, solvent-responsive bending and ultraviolet-light-driven Marangoni locomotion demonstrate its extended actuation capability. This work highlights subnanochannel engineering for advanced humidity-responsive liquid crystal polymer films.
Toxic organic dyes present in wastewater pose a serious threat to environmental and public health, making their effective removal a critical priority. To address this issue, an ionic porous organic polymer (MIPOP) was synthesised using 2-methylbenzimidazole and 4,4′-bis(chloromethyl)- 1,1′-biphenyl via a Friedel-Crafts alkylation reaction, employing FeCl3 as a catalyst. The MIPOP exhibited a high surface area of 1175.63 m2/g with porous morphology. The removal of malachite green dye was successfully achieved using MIPOP, exhibiting a monolayer adsorption capacity of 534.82 mg/g. The optimum conditions of adsorbent dosage, dye concentration, contact time and pH are 0.15 g/L, 100 mg/L, 180 min, and 6, respectively. The adsorption process followed the Freundlich isotherm and pseudo-second-order kinetic models, indicating multilayer chemisorption behaviour. Furthermore, thermodynamic studies confirmed the spontaneous and endothermic nature of the adsorption process. Computational investigations were also performed to correlate the experimental findings with theoretical aspects, and the results showed good agreement with the experimental observations. These outcomes highlight the potential of MIPOP as a robust and sustainable system for advanced environmental remediation.
To simultaneously enhance the physicochemical properties and antimicrobial activity of carboxy methylcellulose (CMC), we designed a novel, multifunctional CMC-based sulfa drug via a straightforward two-step synthetic route. Initially, CMC reacted with cyanogen bromide in a basic medium, followed by combination with three sulfa drug structures, yielding the functionalized CMC-sulfa drug samples via an isourea linkage (CMC/H1–3). The successful functionalization of CMC-sulfa drugs (CMC/H1–3) was validated by 1H NMR and FT-IR spectroscopy, which showed distinct deviations from the spectra of pure CMC. Chemical functionalization of CMC (CMC/H1–3) successfully reduced the polymer's crystallinity, as determined by XRD, while significantly enhancing its thermal stability, as determined by TGA. The modified CMC samples exhibited a reduction in crystallinity index to 51.71%–53.63%, compared to the native CMC (60.59%). The modified samples exhibited enhanced antimicrobial activity against Salmonella typhi (gram-negative) and Staphylococcus aureus (gram-positive), especially the modified CMC containing the sulfamethoxazole drug (CMC/H2), compared to the native CMC. It exhibited dose-dependent antibacterial activity against Salmonella typhi and Staphylococcus aureus, achieving notable inhibition zones of 22 mm and 20 mm, respectively, alongside a uniform minimum inhibitory concentration (MIC) of 15.62 μg/mL. At 75% of MBC, CMC/H2 achieved remarkable bacterial inhibition rates of 92.55% and 89.23%. Computational docking studies demonstrated that the functionalized CMC/H1–3 materials form robust complexes with critical enzymatic targets (Sortase A and DHPS), characterized by highly favorable binding affinities and diverse molecular interactions. Finally, anchoring sulfa drugs, especially sulfamethoxazole, to the CMC matrix through a stable isourea linkage successfully augmented the physicochemical and antimicrobial properties of the CMC polymer.
