Polymer Chemistry最新文献

Incorporation of electron-deficient units into polymer backbones is a promising strategy to enlarge the bandgaps of polymer donor materials. Herein, two wide-bandgap (WBG) polymer donors (P1 and P3) are designed and synthesized by using two different electron-deficient units of 5,10-dihydrodithieno[3,2-c:3′,2′-h][2,6]naphthyridine-4,9-dione (TND) with different side-chains, and 5,6-difluoro-2-(2-hexyldecyl)-2H-benzo[d][1,2,3]triazole. Due to the strong electron-withdrawing ability of both two building blocks, the two copolymers exhibit large optical bandgaps and low-lying highest occupied molecular orbital (HOMO) energy levels, which are matched with the narrow bandgap nonfullerene acceptor of L8-BO. The alkyl chains on the polymer backbones can affect molecular packing and charge transport properties of the copolymers. P3 with 2-butyloctyl side-chains exhibits an enhanced crystallinity and a preferable face-on molecular orientation. When blended with L8-BO, the best P3-based polymer solar cell (PSC) displays a power conversion efficiency (PCE) of 12.56% with an open-circuit voltage (V_OC) of 0.742 V, a short-circuit current density (J_SC) of 22.80 mA cm⁻², and a fill factor (FF) of 74.30%. However, the best-performing P1-based PSC shows a relatively low PCE of 10.37%. This study suggests that the polymer donor materials based on two electron-deficient units have great potential in fabricating efficient nonfullerene PSCs.

A new Tröger's base containing fluorenone organic polymer (TB-FL-COP) was synthesized and used as a fluorescence sensor for discriminative sensing of antibiotics in water. TB-FL-COP showed the highest fluorescence quenching, reversible sensing responses, and excellent sensitivity of 56 ppb level for sulfamethazine antibiotics. The Stern–Volmer quenching constant (K_SV) was calculated to be 1.2 × 10⁶ M⁻¹. The fluorescence sensing ability was also reflected by sharp visual color changes and further demonstrated in real water samples.

We report a convenient bifunctional diazirine reagent that is capable of photochemically modifying inert polymers, particularly those used in fibers and textiles for ballistics and blast protective gear, such as para-aramid and ultra-high molecular weight polyethylene (UHMWPE). The reagent's structure features a trifluoromethyl diazirine group as a precursor to a carbene that binds the textile surface. On the reagent's other terminus, a benzyl bromide group acts as a site accessible for substitution reactions. As a bench-stable liquid, this bifunctional diazirine can be prepared on gram-scale quantities and rapidly activates under long-wave UV light. A series of fabrics made from Kevlar, Spectra, Dyneema, etc. were functionalized with this diazirine reagent, then subsequently dyed by binding nucleophilic dyes. The resulting coloration was found to be robust and colorfast with respect to water, organic solvent, and simulated laundering with detergent, and the strength of the fibers or fabrics was retained through the dyeing process, as shown through TGA and mechanical break testing. Overall, this carbene-based method provides a general, mild strategy for the covalent attachment of small molecules to textiles made from inert polymers, particularly para-aramids and UHMWPE, as well as nylon and fiber blends of these materials, and has potential use in next-generation protective outerwear.

A novel procedure for the synthesis of polyarylethenes is described. Consecutive C–H vinylation reactions of tetraphenylethene with a triphenylethenyl triazene give hyperbranched polyarylethenes of variable sizes. The vinylation reactions are mediated by acid-induced cleavage of the triazene function. In contrast to other procedures for the synthesis of polyarylethenes, our methodology is ‘traceless’, and functional groups are not found in the products. The hyperbranched polyarylethenes show size-dependent luminescence. Larger polymers display increased luminescence in solution but decreased luminescence in the solid state. The polymers exhibit unusual ratiometric aggregation-induced emission. The synthetic methodology can also be used for grafting hyperbranched poly(triphenylethene) to a functional aromatic compound such as benzo-18-crown-6. The coupling product displays a ratiometric luminescence response upon the addition of metal salts.

Color-to-white switching electrochromic devices (ECDs) present great application potential in non-emissive displays and energy-saving fields, but there are still very few reports. In this work, three fused thienothiophene polymers are synthesized via direct arylation polymerization (DArP), and the optical absorption is tuned by incorporating different embedded units into the fused thienothiophene mainchain. The resultant polymers demonstrate good electrochromic properties such as high optical contrast, fast switching response and good stability, and are also highly transmissive in the oxidized state. Additionally, a quasi-solid white electrolyte with a reflectivity of 75%, ionic conductivity of 8.1× 10⁻⁶ S cm⁻¹ and mechanical strength of 1.33 MPa is prepared by optimizing the composition of the polymer, TiO₂, and ion liquid. Then, three color-to-white electrochromic devices (ECDs) are successfully fabricated by combining the synthesized polymers and the white electrolyte, and also present good electrochromic properties such as high optical contrast, fast switching response, good stability, etc.

A novel trifluorovinyl-ether (–OCFCF₂, TFVE) functionalized diamine (DA-TFVE) with a triarylmethane structure was successfully obtained from renewable vanillin through a Brønsted acidic ionic liquid catalyzed Friedel–Crafts reaction. Subsequently, traditional two-step condensations between DA-TFVE and dianhydride (6FDA and CBDA) were used to prepare two linear polyimides (PI-1 and PI-2, respectively) containing TFVE side groups. Both polyimides exhibited excellent film-forming ability and good solubility in common organic solvents. Upon heating, the linear polyimides could be transformed into cross-linked polyimides (cPI-1 and cPI-2) with perfluorocyclobutyl (PFCB) ether linkers through thermal [2π + 2π] post-polymerization of TFVE groups. Surprisingly, both cPI-1 and cPI-2 exhibited high mechanical strength with a storage modulus of more than 2.0 GPa at room temperature, as well as outstanding thermal stability with glass transition temperatures of 402 °C and 374 °C, respectively. The polymer films before and after thermal crosslinking showed high transparency. In particular, a transmittance of 73% at 450 nm and 81% at 500 nm was observed for the colorless polyimide PI-2 with aliphatic segments. X-ray diffraction results of the obtained PIs showed that the average inter-chain distances (d-spacing) were 0.44–0.59 nm, indicating the hindered chain packing caused by PFCB linkers between the polymer chains. All these results suggested their potential application as candidate materials in high-performance packaging and flexible electronics.

Polymeric capsules with core–shell structures have been widely explored for molecule separations, energy storage, and catalysis, among other applications. To tailor the application-oriented performance of these structures, researchers have imparted stimuli-responsive properties to the shells. In contrast to capsules with “static” shells, stimuli-responsive capsule shells not only protect the core from the external environment, but also aid in handling and impart properties such as on-demand release of cargo and varied shell permeability, as well as provide a platform for the fabrication of advanced structures. The composition and properties of polymer shells can be tuned through incorporation of dynamic covalent bonds into the polymer backbones, or introduction of segments or pendant side chains which can leverage intermolecular (e.g., hydrogen bonding) or electrostatic interactions to give response. Most reports on responsive polymer capsules focus on their application in cargo delivery, a topic that is heavily reviewed elsewhere. In complement, this minireview addresses responsive polymer capsules and their applications beyond drug delivery, focusing on structure–property relationships. We first highlight the most common fabrication techniques for core–shell structures including hard template, soft template, and microfluidic methods, among which we emphasize our utilization of interfacial polymerization and polymer precipitation within a Pickering emulsion template. We then provide a concise review of commonly employed chemistries for responsive polymer shells based on stimuli, including our contribution on the incorporation of dynamic covalent polymer backbones into thermo-responsive capsule shells. Application-oriented performances of the responsive core–shell structures are then highlighted. Finally, we outline opportunities for advancing the performance-related properties of responsive capsules, wherein we propose new directions where responsive polymer-based capsules can have critical impact in the development of new technologies.

Porous organic polymers (POPs) possess versatile advantages, such as light weight, excellent stability, and high porosity. Hence, POPs could be ideal functional platforms. Herein, two multifunctional M-POPs were prepared via the Schiff-base reaction. They possessed good microporosity, remarkable stability, high-density N/O atoms, and excellent luminescence. Interestingly, the M-POPs achieved a good carbon dioxide-capture value of 17.1 wt% at 273 K and 1 bar, and provided excellent H₂ capture of 1.0 wt% at 77 K and 1 bar. The M-POPs had many hydroxyl groups and nitrogen on the walls, which aided the formation of metal-coordination sites. The M-POPs had an excellent capacity for the detection of metal ions that was accurate, selective, and sensitive. Furthermore, phospholipid-coated M-POPs could be used to detect metal ions in living cells. These results provide a new design for multifunctional POPs.