End Groups Research Articles

Mechanochromic Displays Based on Photoswitchable Cholesteric Liquid Crystal Elastomers.

Stimuli responsive optical materials are attractive for many areas, from healthcare to art design. However, creating intricate color-changing patterns for visual information is still a challenge. This work describes the preparation of mechanochromic structural colored intricate pictures imprinted in cholesteric liquid crystal elastomers by using a chiral isosorbide molecular photo-switch. The photo-switch contains a photoisomerizable cinnamate moiety and was incorporated in a main chain liquid crystal oligomer with photopolymerizable acrylate end groups. After coating, the structural colored film was irradiated with ultraviolet (UV) light in air causing E/Z isomerization of the cinnamate units leading to a redshift of the structural color of the film. A grayscale photomask was used to spatially control the photoisomerization reaction and imprint colorful pictures such as portraits and landscapes, in the cholesteric liquid crystal films with high resolution. Photopolymerization in a nitrogen atmosphere led to a mechanochromic cholesteric liquid crystal elastomer with striking structural colors that blueshift upon strain independently. The sharp details of the patterns were preserved even under deformation and the system returned to the initial state upon strain removal. Our work offers a simple photo-switch approach to prepare stimuli responsive optical polymers imprinted with color-changing pictures of unprecedented complexity.

A transparent, anti‐blue‐light, and high strength nylon/nickel phosphate oligomer nanocomposite formed via intermolecular hydrogen bond crosslinking

AbstractPolymer/transition metal inorganic salts nanocomposites are promising engineering materials in automotive, electronics, aerospace and smart wearables fields. However, the interfacial incompatibility always causes agglomeration and phase separation, constraining their further application. Inspired by inorganic oligomers' polymerization, nylon/nickel phosphate oligomer (NPO) nanocomposite (ENCC) was prepared via hydrogen bond crosslinking method. Due to the formation of hydrogen bonds between PO43− end groups of NPO with an average diameter of 6.5 ± 1.2 nm and NH groups on the nylon molecular chain, the phase compatibility is greatly improved. Hence, NPO was uniformly nano‐dispersed and had no obvious agglomerate in ENCC, inducing an invisible phase interface at nano‐micro scale. Nylon/nickel phosphate oligomer showed an excellent reinforcing effect on nylon, the tensile strength and elongation of ENCC reached 28 ± 0.8 MPa and 585 ± 26% at a high loading of 20 wt%, increased by 155% and 92%, compared with pure matrix, respectively. Furthermore, ENCC was still optically transparent and had excellent anti‐blue‐light performance (up to 96.6%).Highlights Novel inorganic/nylon composite prepared by hydrogen bond crosslinking method. Phase separation and aggregation problems were solved remarkably. Inorganic metal phosphate dispersed with a diameter of 6.5 ± 1.2 nm. The composite was still transparent at 20 wt% loading of metal phosphate. Tensile strength and elongation increased by 155% and 92%, respectively.

How to configure the supply chain to stimulate firm innovation performance?

Supply chain characteristics are an important driving force for innovation at the focal firm. Previous research has separately examined the impact of structural, relational, and capability dimensions of the supply chain on firm innovation. Relying on the structure-relationship-capability framework, this study explores the configurational impact of geographical distance, business concentration, and partner innovation of both the supplier-base and the customer-base on firm innovation. Necessary causality analysis (NCA) and fuzzy-set qualitative comparative analysis (fsQCA) are employed. Based on a dataset of 123 Chinese listed firms in high-tech manufacturing sectors, we provide novel insights on the antecedent configurations of the partner characteristics in both ends of supply chains for facilitating firm innovation. Our findings indicate that there are no necessary conditions for high firm innovation performance. We identify three distinct paths - namely, innovation-driven, customer-dominated, and relationship-driven configurations - that consistently lead to high firm innovation performance. From a configurational perspective, this research contributes to the innovation and supply chain literature and provides practical implications for managers to facilitate firm innovation.

Analysis Of Strategies for Strengthening the Online Game Industry Using an Industrial Cluster Approach

Based on data, as one of the creative economy sectors, the game industry has much potential to boost the Indonesian economy. The total market value of the games industry in Indonesia is US$ 1.92 billion or 25 trillion rupiah. However, Foreign developers from Europe and the US dominate the games industry market in Indonesia, making Indonesia only able to contribute 0.49% of total revenue. This research aims to map Indonesia's game industry players, analyse its ecosystem's environmental determinants, and formulate effective industry development strategies. This qualitative research uses interview methods with key informants, observation, and literature study, with purposive sampling as a sampling technique. The results show that the core industry value chain of the game industry cluster consists of Game Developers and Game Publishers and is supported by Supply industries (hardware providers, HR, digital content, and financial services) and supporting industries (marketing, logistics, law, and networks). There are related institutions/institutions such as the Ministry of Tourism and Creative Economy, the Coordinating Ministry for Maritime and Investment Affairs, the Ministry of Communications and Informatics, the Ministry of Education and Culture, and the Indonesian Game Association. This industry is also related to animation, music, e-sports and tourism. This value chain ends with buyers. This research recommends concrete steps for relevant agencies to enhance the gaming industry ecosystem through human resource development, increasing access to financing, promotion and providing technological infrastructure. Collaboration across industries is expected to increase the global competitiveness and contribute significantly to the national creative economy.

Ultrastrong, Ductile, Tear- and Folding-Resistant Polyimide Film Doubly Reinforced by an Aminated Rigid-Rod Macromolecule and Graphene Oxide.

As a high-performance polymer with exceptional mechanical, thermal, and insulating properties, polyimide (PI) has been widely used as flexible circuit substrates for microelectronics, portable electronics, and wearable devices. Due to the growing demand for further thinning and lightweighting of electronic products, PI films need to have further enhanced mechanical properties. Traditional nanofiller-reinforced PI films often exhibit reduced ductility and limited improvements in strength. Therefore, it remains a challenge to simultaneously improve the strength and toughness of PI films while preserving their ductility. In this study, we report an exceptionally strong and ductile PI doubly reinforced by one-dimensional rigid-rod para-aramid, poly(p-aminophenylene aminoterephthalamide ((NH2)2-PPTA), and two-dimensional graphene oxide (GO) nanosheets. The amino side groups of (NH2)2-PPTA react with the anhydride end groups of PI, forming covalent bonds. At a (NH2)2-PPTA content of only 0.4 wt %, the (NH2)2-PPTA/PI film displays significantly enhanced mechanical properties. When 0.4 wt % of GO is added together with (NH2)2-PPTA, the tensile strength, tensile toughness, and strain at break reach 284.8 ± 5.3 MPa, 277.9 ± 7.6 MJ/m3, and 132.6 ± 3.8%, which are ∼178, ∼312, and ∼51% higher, respectively, than those of pure PI. Moreover, the doubly reinforced PI film also exhibits a 206% increase in tear strength and significantly enhanced folding resistance. The dual reinforcement of PI with (NH2)2-PPTA and GO improves the mechanical properties more efficiently than any single reinforcing agents previously reported and overcomes the disadvantage of most inorganic nanofillers that reduce ductility.

Light Switchable Bioorthogonal Reaction Manifold for Modulation of Hydrogel Properties.

Chemical reaction systems that can occur via multiple pathways in a controllable fashion are highly attractive for advanced materials applications and biological research. In this report, we introduce a bioorthogonal reaction manifold based on a chalcone pyrene (CPyr) moiety that can undergo either red-shifted photoreversible [2 + 2] cycloaddition or thiol-Michael addition click reaction. By coupling the CPyr to a water-soluble poly(ethylene glycol) end group, we demonstrate the efficient polymer dimerization and cleavage by blue light (λ = 450 nm) and UV light (λ = 340 nm), respectively. In the absence of light, CPyr rapidly reacts with thiols in aqueous environments, enabling fast and efficient polymer end-group functionalization. The chemical reaction manifold was further employed in polymer cross-linking for the preparation of hydrogels whose stiffness and morphology can be modulated by different photonic fields or the addition of a thiol cross-linker. The photoreversible cycloaddition and thiol-Michael addition click reaction can be used in conjunction for spatial and temporal conjugation of a streptavidin protein. Both cross-linking conditions are nontoxic to various cell lines, highlighting their potential in biomaterials applications.

End Cap Effect on Solution-Processable Deep Blue Lasing Materials with Low-Amplified Spontaneous Emission Thresholds.

Organic lasers have attracted increasing attention owing to their superior characteristics such as lightweight, low-cost manufacturing, high mechanical flexibility, and high emission-wavelength tunability. Recent breakthroughs include electrically pumped organic laser diodes and an electrically driven organic laser, integrated with an organic light-emitting diode pumping. However, the availability of efficient deep blue organic laser chromophores remains limited. In this study, we develop two novel rigid oligophenylenes, end-capped with carbazole and phenylcarbazole groups, to demonstrate exceptional optical and amplified spontaneous emission (ASE) properties. These oligophenylenes are not only solution processable but also exhibit remarkably high solution photoluminescence quantum yields (PLQYs) of 90% and high radiative rates of 1.35 × 109 s-1 in the deep blue range. Our theoretical calculations confirm that the carbazole and phenylcarbazole end groups play a pivotal role in enhancing the optical transitions of the oligophenylene laser chromophores, thereby elevating their emission oscillator strengths. Remarkably, these materials demonstrate low solid-state ASE threshold values of 1.0 and 1.5 μJ/cm2 (at 431 and 418 nm, respectively). To the best of our knowledge, these ASE thresholds represent the lowest reported at these specific ASE wavelengths in the literature, regardless of whether they are solution-processed or thermally evaporated films. Furthermore, they exhibit excellent thermal and photostability, low triplet quantum yields, as well as negligible overlap of excited-state absorption within the ASE emission region, making them excellent candidates for a new class of deep blue materials for organic lasers. By integrating insights from theoretical calculations and experimental validation, our study provides a comprehensive understanding of the design principles behind these high-performing organic laser chromophores, paving the way for the development of advanced organic lasers with enhanced performance characteristics.

Halogen-Functionalized Hole Transport Materials with Strong Passivation Effects for Stable and Highly Efficient Quasi-2D Perovskite Solar Cells.

The performance of quasi-two-dimensional (Q-2D) perovskite solar cells (PSCs) strongly depends on the interface characteristics between the hole transport material (HTM) and the perovskite layer. In this work, we designed and synthesized a series of HTMs with triphenylamine-carbazole as the core structure and modified end groups with chlorine and bromine atoms. These HTMs show deeper highest occupied molecular orbital energy levels than commercial HTMs. This reduced energy band mismatch between the HTM and perovskite layer facilitates efficient charge extraction at the interface. Moreover, these HTMs containing halogen atoms on the end groups could form halogen bonding with the Pb2+ ions at the buried interface of the perovskite layer, effectively passivating defects to suppress nonradiative recombination. Additionally, halogen bonding also contributes to the formation of vertically oriented perovskite crystals with a high quality. By incorporation of chlorohexane-substituted HTMs, the resultant Q-2D PSCs exhibited the highest power conversion efficiency of 21.07%. Furthermore, the devices show improved stability, retaining 97.2% of their initial efficiency after 1100 h of continuous illumination.

Ambient cationic ring-opening polymerization of Dibenzo[c,e]oxepine-5(7H)-thione (DOT): Thermal and nucleophile-initiated depolymerization

With rising concern over plastic waste accumulation worldwide, the quantitative depolymerization of polymers into small molecule building blocks offers avenues toward a circular polymer economy. But a remaining challenge consists in tuning the degradation behaviour of polymers to ensure stability during use and efficient recyclability after use. Herein, the thionolactone dibenzo[c,e]oxepine-5(7H)-thione (DOT) is shown to undergo cationic ring-opening polymerization (CROP) under ambient conditions without the need for inert atmosphere or dry solvents. Involving S–O isomerization, the polymerization gave polythioesters in near-quantitative conversions with tuneable SEC-measured molar masses from 1.3–50 kg/mol and dispersities between 1.5 and 2.0. The polythioesters could be degraded with an excess of amine, with substoichiometric amounts of thiolate (which was shown to involve depolymerization from a thiolate ω-end group), or thermally. The latter two conditions produced the thiolactone dibenzo[c,e]thiepine-5(7H)-one (DTO). While anionic ring-opening polymerization (the common route to polythioesters) gives thiol end groups, the CROP presented herein provided end-capped polymers. Interestingly, the choice of initiator (and resulting end cap) was shown to have a drastic influence on the thermal stability. While a boron trifluoride-initiated polymer showed only 6 % decomposition when heated to 140 °C without solvent, a comparable methyl triflate-initiated polymer underwent 35 % degradation to DTO when heated to the same temperature overnight.

Achieving 19.5% Efficiency via Modulating Electronic Properties of Peripheral Aryl-Substituted Small-Molecule Acceptors.

The advancement of acceptors plays a pivotal role in determining photovoltaic performance. While previous efforts have focused on optimizing acceptor-donor-acceptor1-donor-acceptor (A-DA1-D-A)-typed acceptors by adjusting side chains, end groups, and conjugated extension of the electron-deficient central A1 unit, the systematic exploration of the impact of peripheral aryl substitutions, particularly with different electron groups, on the A1 unit and its influence on device performance is still lacking. In this study, three novel acceptors - QxTh, QxPh, and QxPy - with distinct substitutions on the quinoxaline (Qx) are designed and synthesized. Density functional theory (DFT) analyses reveal that QxPh, featuring a phenyl-substituted Qx, exhibits the smallest molecular binding energies and a tightest π···π stacking distance. Consequently, the PM6:QxPh device demonstrates a better power conversion efficiency (PCE) of 17.1% compared to the blends incorporating QxTh (16.4%) and QxPy (15.7%). This enhancement is primarily attributed to suppressed charge recombination, improved charge extraction, and more favorable molecular stacking and morphology. Importantly, introducing QxPh as a guest acceptor into the PM6:BTP-eC9 binary system yields an outstanding PCE of 19.5%, indicating the substantial potential of QxPh in advancing ternary device performance. The work provides deep insights into the expansion of high-performance organic photovoltaic materials through peripheral aryl substitution strategy.

Phenothiazine-carbazole-based bis oxime esters (PCBOEs) for visible light polymerization

In this study, a series of seven PCBOEs was innovatively designed and successfully synthesized for the first time by bridging a phenothiazine and a carbazole unit by mean of an acetylene spacer and bearing oxime ester groups as end groups on both sides. Structures of the different difunctional oxime esters were confirmed through NMR and HRMS. All PCBOEs exhibited excellent light absorption properties in the visible range. Upon excitation with a 405 nm LED for 60 s, a complete photolysis of the oxime esters could be achieved. Parameters such as the singlet state energy and the triplet state energy demonstrated the facile generation of the corresponding radicals upon light absorption by PCBOEs. Photopolymerization kinetics in TMPTA confirmed the homolytic cleavage of oxime esters and the generation of radicals. CO2 absorption peaks were detected when the PCBOEs/TMPTA systems were excited with a 405 nm LED. Based on the positive results, the photochemical mechanisms of polymerization with PCBOEs was proposed. PCBOE3 was identified as the best candidate of the series and this bifunctional oxime ester was successfully used for the 3D-printing of the “IS2M” logo via DLW. Experimental results from DSC also confirmed that PCBOEs not only serve as photoinitiators but also possess high reactivity as thermal initiators.

Electrical Conductivity Characteristic of Polyimide under Long-Term Combined Electron Irradiation and Thermal Cycle in Vacuum.

During long-term operation, low-earth-orbit spacecraft are exposed to a severe environment of electron irradiation and thermal cycle. This affects the electric properties of polyimide, an essential insulation material for spacecraft electrical transmission equipment, particularly the conductivity characteristic. Therefore, this paper investigates the conductivity and its evolution of polyimide after the combination of 20 keV, 8 nA/cm2 electron irradiation, and 243-343 K, 5 K/min thermal cycle in a vacuum environment for 432 h. The results show that the conductivity increases by about 2 orders of magnitude over 432 h, with the threshold field for electric-field-dependent conductivity decreasing. The conductivity growth rate varies, rising during the first 192 h, then increasing in the midelectric field, and decreasing in the high electric field regions. The thermally stimulated depolarization current method demonstrates that increases in γ, β1, and β2 trap densities, associated with enhanced motility of end groups, diamines, and dianhydrides after long-chain breaks, lead to higher conductivity and growth rate. Additionally, increases in β3 and α trap densities, related to increased C═O bonds and free radicals, reduce the threshold field and the conductivity growth rate in the range of 57.0-100.0 kV/mm after 192 h. These findings provide a reference for the performance evaluation and enhancement of spacecraft polyimide materials.

Studies on the Termination Behavior of Styrenic Free‐Radicals

AbstractIn order to provide more evidence to understand the termination mechanism in styrene free‐radical polymerization, (1‐bromoethyl) benzene and polystyrene with bromide end group (PSt‐Br) synthesized by atom transfer radical polymerization (ATRP) were used as the model compound and model polymer to study the termination behavior of styrenic radical by atom transfer radical coupling (ATRC), and then the NMR chemical shifts of the head‐to‐head enchainment from coupling termination were obtained. SEC and different NMR measurement methods were used to analyze and characterize the products. It is confirmed that there is no bimolecular disproportionation termination between styrenic free radicals, but only coupling termination to form the head‐to‐head enchainment. The proton and carbon chemical shifts of the head‐to‐head enchainment from coupling termination for (1‐bromoethyl) benzene are 2.7–2.86 ppm and ~47.3 ppm. As for the polystyrene through ATRC from PSt‐Br, the corresponding chemical shifts are 2.61–3.29 ppm and ~46.4 ppm, respectively, they are almost the same as the data in our previous paper (~3.05 ppm, ~46.6 ppm) for polystyrene initiated by BPO, proving that the chain termination in free‐radical polymerization of styrene initiated by BPO occurs through primary termination between chain radical and primary radical rather than bimolecular termination between chain radicals.

Poly(2-alkyl/aryl-2-oxazoline)-Imidazole Complexes as Thermal Latent Curing Agents for Epoxy Resins.

One-component epoxy resins (OCERs) with improved stability (shelf life) and controlled curing temperatures were prepared using epoxy resins and polyoxazoline-imidazole (POZ-Im) based thermal latent curing agents (TLCs). POZ homopolymers with molar masses of 1000, 2000, and 5000 g/mol were obtained via cationic ring-opening polymerization (CROP) of 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-pentyl-2-oxazoline, and 2-phenyl-2-oxazoline. TLCs were prepared by physically entrapping imidazole, the curing agent, in the POZ matrix at the homopolymer/Im (HP/Im) ratios of 1:1 and 5:1 and characterized by FTIR and TGA. TLCs were then mixed with bisphenol A diglycidyl ether (DGEBA) to obtain OCERs with Im concentrations of 1, 3, and 5 wt %. Dynamic DSC tests were performed to determine the effect of the pendant group and molar mass of POZ, the POZ/Im ratio, and Im concentration on the curing behavior of the OCERs, whereas isothermal DSC tests were carried out to examine their thermal stability and optimal curing temperatures. Optical microscopy was performed to study the compatibility of the TLCs with DGEBA. This study showed that the dispersion quality of TLCs is highly associated with the compatibility of POZs and DGEBA, which affected the release of Im, thus left limit temperatures of curing. In addition, higher left limit temperatures were obtained when the POZ/Im ratio increased. Isothermal DSC results conformed to the improved stability and better thermal latency of the samples with a POZ/Im ratio of 5:1. Moreover, the higher left limit temperatures were obtained with the lowest molar mass of POZ due to the better interaction between the -OH end group of POZ and Im. The shelf life of PEOZ 1K-Im 5:1 1% OCER was predicted at -20, 0, and 20 °C, with an estimated 15.3 days at 20 °C using isothermal DSC and rheology at 50, 60, and 70 °C. Overall, this research contributes to the development of OCERs by introducing POZ-Im complexes as novel TLCs. The findings shed light on the importance of compatibility in achieving optimal dispersion and release of Im and the role of the POZ/Im ratio and POZ molar mass in controlling left limit temperatures, ultimately influencing the curing behavior of OCERs.

Efficient Synthesis of μ-A(BC)C Miktoarm Star Polymer Assemblies via Aqueous Photoinitiated Polymerization-Induced Self-Assembly.

In this study, green light-activated photoiniferter reversible addition-fragmentation chain transfer (RAFT) polymerization of glycerol methacrylate was performed using an ω,ω-heterodifunctional macro-RAFT agent. Because of the different RAFT controllability of two RAFT groups toward methacrylic monomers, only one RAFT group was activated under green light irradiation, leading to the formation of a diblock copolymer macro-RAFT agent with one RAFT group located at the chain end and the other RAFT group located between two blocks. The obtained diblock copolymer macro-RAFT agent was then used to mediate aqueous photoinitiated RAFT dispersion polymerization of diacetone acrylamide (DAAM), which formed μ-A(BC)C miktoarm star polymer assemblies with a diverse set of morphologies. Comparing with the ABC triblock copolymer, it was found that the architecture of the μ-A(BC)C miktoarm star polymer facilitated the formation of higher-order morphologies. Kinetic studies indicated that the aqueous photoinitiated RAFT dispersion polymerization exhibited ultrafast polymerization behavior, with quantitative monomer conversion being achieved within 5 min. Size exclusion chromatography analysis confirmed that good RAFT control was maintained during the polymerization. A morphological phase diagram for μ-A(BC)C miktoarm star polymer assemblies was constructed by varying the monomer concentration and the [DAAM]/[Macro-RAFT] ratio. We expect that this study not only develops an approach for the preparation of miktoarm star polymer assemblies but also provides mechanistic insights into the polymerization-induced self-assembly of nonlinear polymers.

Approaching 20% Efficiency in Ortho-Xylene Processed Organic Solar Cells by a Benzo[a]phenazine-Core-Based 3D Network Acceptor with Large Electronic Coupling and Long Exciton Diffusion Length.

High-performance organic solar cells often rely on halogen-containing solvents, which restrict the photovoltaic industry. Therefore, it is imperative to develop efficient organic photovoltaic materials compatible with halogen-free solvents. Herein, a series of benzo[a]phenazine (BP)-core-based small-molecule acceptors (SMAs) achieved through an isomerization chlorination strategy is presented, comprising unchlorinated NA1, 10-chlorine substituted NA2, 8-chlorine substituted NA3, and 7-chlorine substituted NA4. Theoretical simulations highlight NA3's superior orbit overlap length and tight molecular packing, attributed to interactions between the end group and BP unit. Furthermore, NA3 demonstrates dense 3D network structures and a record electronic coupling of 104.5 meV. These characteristics empower the ortho-xylene (o-XY) processed PM6:NA3 device with superior power conversion efficiency (PCE) of 18.94%, surpassing PM6:NA1 (15.34%), PM6:NA2 (7.18%), and PM6:NA4 (16.02%). Notably, the significantly lower PCE in the PM6:NA2 device is attributed to excessive self-aggregation characteristics of NA2 in o-XY. Importantly, the incorporation of D18-Cl into the PM6:NA3 binary blend enhances crystallographic ordering and increases the exciton diffusion length of the donor phase, resulting in a ternary device efficiency of 19.75% (certified as 19.39%). These findings underscore the significance of incorporating new electron-deficient units in the design of efficient SMAs tailored for environmentally benign solvent processing of OSCs.

Preparation of bacterial cellulose/acrylic acid-based pH-responsive smart dressings by graft copolymerization method

Conventional wound dressings used in trauma treatment have a single function and insufficient adaptability to the wound environment, making it difficult to meet the complex demands of the healing process. Stimuli-responsive hydrogels can respond specifically to the particular environment of the wound area and realize on-demand responsive release by loading active substances, which can effectively promote wound healing. In this paper, BC/PAA-pH responsive hydrogels (BPPRHs) were prepared by graft copolymerization of acrylic acid (AA) to the end of the molecular chain of bacterial cellulose (BC) network structure. Antibacterial pH-responsive ‘smart’ dressings were prepared by loading curcumin (Cur) onto the hydrogels. Surface morphology, chemical groups, crystallinity, rheological, and mechanical properties of BPPRHs were analyzed by different characterization methods. The drug release behavior under different physiological conditions and bacteriostatic properties of BPPRH-Cur dressings were also investigated. The results of structural characterization and performance studies show that the hydrogel has a three-dimensional mesh structure and can respond to wound pH in a ‘smart’ drug release capacity. The drug release behavior of the BPPRH-Cur dressings under different environmental conditions conformed to the logistic and Weibull kinetic models. BPPRH-Cur displayed good antimicrobial activity against common pathogens of wound infections such as E. coli, S. aureus, and P. aeruginosa by destroying the cell membrane and lysing the bacterial cells. This study lays the foundation for the development of new pharmaceutical dressings with positive health, economic and social benefits.

Synthesis of biodegradable polydisulfides from renewable resources

In this paper, we report the synthesis and preliminary characterization of polydisulfides from a renewable resource. Di-linoleic diol was first converted into dithiol via transesterification of methyl-3-mercaptopropionate catalyzed by Candida antarctica Lipase B (CALB). The kinetics of the reaction was monitored using a newly developed Thin Layer Chromatography method. The dithiol was then polymerized by Reversible Radical Recombination Polymerization (R3P), a scalable “green” polymerization process using triethylamine (TEA) catalyst, aqueous H2O2, and air. 3 wt% H2O2 yielded low molecular weight polymer, while with 30 wt% concentration DL-SS with Mn = 66,400 g/mol and polydispersity of 1.26 was obtained. 800 MHz NMR and Raman spectroscopy did not detect thiol end group signals in this polymer, indicating that it had a cyclic structure. Dithiothreitol degraded the polymer to monomer in two weeks. Full characterization of this new polymer is in progress.

The Multi-Functional Third Acceptor Realizes the Synergistic Improvement in Photovoltaic Parameters and the High-Ratio Tolerance of Ternary Organic Photovoltaics.

The ternary strategy proves effective for breakthroughs in organic photovoltaics (OPVs). Elevating three photovoltaic parameters synergistically, especially the proportion-insensitive third component, is crucial for efficient ternary devices. This work introduces a molecular design strategy by comprehensively analyzing asymmetric end groups, side-chain engineering, and halogenation to explore the outstanding optoelectronic properties of the proportion-insensitive third component in efficient ternary systems. Three asymmetric non-fullerene acceptors (BTP-SA1, BTP-SA2, and BTP-SA3) are synthesized based on the Y6 framework and incorporated as the third component into the D18:Y6 binary system. BTP-SA3, featuring asymmetric terminal (difluoro-indone and dichloride-cyanoindone terminal), with branched alkyl side chains, exhibited high open-circuit voltage (VOC), balanced crystallinity and compatibility, achieving synergistic enhancements in VOC (0.862V), short circuit-current density (JSC, 27.52mA cm-2), fill fact (FF, 81.01%), and power convert efficiency (PCE, 19.19%). Device based on D18/Y6:BTP-SA3 (layer-by-layer processed) reached a high efficiency of 19.36%, demonstrating a high tolerance for BTP-SA3 (10-50%). This work provides novel insights into optimizing OPVs performances in multi-component systems and designing components with enhanced tolerance.

Tuning Stopper Size in Multiresponsive [2]Rotaxanes for Fluoride Anion Selective Metastability.

[23]Crown-7-ether incorporated [2]rotaxanes, comprising an anthracene blocker and 4-isopropylphenyl/cyclohexyl end groups, exhibited varying degrees of metastability with a range of chemical (base, halide anions) and physical (solvent, heat) stimuli. Among halides, fluoride, chloride, and bromide anions affected the deslippage of 23-crown-7-ether in 4-isopropylphenyl stoppered [2]rotaxane. Surprisingly, only fluoride anions could selectively induce deslippage in cyclohexyl stoppered [2]rotaxane, whose fluorescence quenching provided an additional tool to selectively detect the fluoride anions down to 2.49 × 10-7 M.