ABSTRACT The lithium‐ion battery (LIB) market continues to expand and must now meet increasingly stringent regulatory sustainability requirements. To mitigate the impact of petrochemical‐derived polymer electrolytes, bio‐sourced polymers have attracted intense interest. In the present work two cellulose derivatives, methyl cellulose (MC) and cellulose acetate butyrate (CAB), were doped with lithium perchlorate (LiClO 4 ) and plasticized with ethylammonium nitrate (EAN), a biodegradable protic ionic liquid synthesized in‐house, to give free‐standing, intrinsically self‐healing biopolymer electrolytes (BPEs). All EAN‐plasticized membranes exceed the 10 −5 S cm −1 threshold conventionally required of a battery separator‐electrolyte. The best membrane, B(MC‐IL)0.2, delivers an ionic conductivity of 6.84 × 10 −4 S cm −1 at room temperature; and investigation on placticized membrane with higher proportion (05 wt%: B(MC‐IL)0.5) shows some changes on membrane surface, affecting the SEI, thus the conductivity of the membrane (5.45 × 10 −4 S cm −1 , RT). An operationally defined electrochemical stability window of 4.4 ± [0.2] V vs. Li + /Li is obtained by linear sweep voltammetry. An optical healing efficiency of ∼99% is reached after 3 h at 60°C, and recovery of some relevant functions of the membranes are assessed by impedance spectroscopy and tensile testing before damage and after healing.
ABSTRACT Photochromic polymer films combining rapid response, prolonged information retention, mechanical robustness, and facile processability are promising for reusable information recording. Herein, a transparent composite film was developed by solution casting of TiO 2 nanoparticles (NPs), polyviologen (PXV), poly(vinyl alcohol) (PVA), and poly(vinylpyrrolidone) (PVP). TiO 2 acts as a photoinduced electron donor, promoting the reduction of PXV 2 + to colored PXV +· , and enabling rapid coloration within 2 s under 365 nm ultraviolet (UV) irradiation. The film exhibits high optical transparency (>85%) and stable photochromic cycling, with an absorbance variation of less than 10% after 20 cycles. The colored information remains recognizable for up to 5 d and gradually fades through oxidation by atmospheric O 2 , with nearly complete decoloration after approximately 16 d. The film also exhibits good thermal stability and mechanical robustness, with a temperature corresponding to 20% mass loss ( T d,20% ) of 274.8°C and a tensile strength of 69.88 MPa. These features make the film promising for ink‐free rewritable patterning and optical information encryption.
ABSTRACT In this work, a comprehensive investigation of the co‐curing behavior, chemical transformations during network formation, and thermal properties of dicyanate ester of bisphenol E (DCBE)/benzoxazine (BZ) (75/25 wt.%) systems modified with epoxycyclohexyl‐functionalized polyhedral oligomeric silsesquioxane (ECH‐POSS) was carried out to establish the role of the reactive nanofiller in the structure and properties of hybrid organic–inorganic polycyanurate (PCN)/polybenzoxazine (PBZ)/ECH‐POSS nanocomposites. DSC revealed a complex three‐stage curing process and demonstrated that ECH‐POSS selectively accelerated the cyanate ester component, while only weakly affecting BZ polymerization. At 2 wt.% ECH‐POSS, the curing onset decreased from 113°C to 91°C, the main exothermic peak shifted from 241°C to 220°C, the induction period decreased by ∼28%, and the reaction rate at a fixed heating time increased more than threefold. FTIR and 1 H/ 1 3 C NMR analyses provided evidence for chemical coupling between DCBE and BZ through the formation of triazine, iminocarbonate, and carbamate structures. Incorporation of only 0.025–0.5 wt.% ECH‐POSS dramatically increased the glass transition temperature ( T g ) of hybrid nanocomposites by 14°C–21°C, reaching 214°C at 0.025 wt.% ECH‐POSS. They retained high thermal stability and char yields of 43%–44% at 790°C. These results demonstrate that reactive ECH‐POSS effectively allows for combining lower‐temperature curing with substantial T g enhancement, providing a promising strategy for the design of high‐performance thermosetting nanocomposites.
ABSTRACT A dual‐responsive amphiphilic diblock copolymer, poly(ethylene oxide)‐ b ‐poly((7‐(4‐vinyl‐benzyloxyl)‐4‐methylcoumarin)‐ co ‐(4‐vinylbenzyl methyl‐diethanol ammonium boronate)) (PEO 45 ‐ b ‐P(VBC 2 ‐ co ‐VMAB 9 )), is designed and synthesized via free radical polymerization for constructing partially reversible core cross‐linking polymer micelles (PM). The coumarin moieties in the hydrophobic core undergo [2 + 2] photocycloaddition under 365 nm irradiation and partial photoscission under 254 nm irradiation, enabling tunable core crosslinking density. The ammonium‑boronate zwitterionic pairs in PVMAB segments exhibit temperature‑dependent inter‑ and intra‑chain association changes, dynamically modulating core hydrophobicity and compactness. UV‑‐vis absorption and fluorescence emission spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM) collectively corroborate the partially reversible photo‐crosslinking and thermo‐responsive zwitterionic association. PM possess a slightly positive charge, which may enhance colloidal stability while facilitating cellular uptake. The resulting micelles can also efficiently encapsulate doxorubicin (DOX) and show finely controlled drug release by varying irradiation duration and temperature. Blank PM demonstrate excellent biocompatibility, while DOX‑loaded PEO 45 ‐ b ‐P(VBC 2 ‐ co ‐VMAB 9 ) polymer micelles (DOX‐PM) exhibit significantly enhanced cytotoxicity against HeLa and MCF‑7 cells under short‐term 365 nm irradiation and hyperthermic conditions (42 °C). This work provides a simple and versatile strategy for spatiotemporally controllable, reusable, and efficient dual‑responsive drug delivery.
