Copolymerization Of Monomers Research Articles

Study on Ring-Opening Copolymerization of Trioxymethylene and Second Monomer Initiated by Phosphotungstic Acid

In this study, a series of polyoxymethylene copolymers are synthesized by bulk cationic ring-opening polymerization by 1,3,5-trioxane (TOX) with 1,3-dioxolane (DOX), octamethylcyclotetrasiloxane (D4), and cyclohexane oxide (CHO) as the second monomer using phosphotungstic acid (PTA) as an initiator. The polymer products were characterized by hydrogen nuclear magnetic resonance (1H-NMR), infrared spectroscopy (IR), thermogravimetry (TG), and differential scanning calorimetry (DSC). And the copolymerization energy barrier was calculated at the b3lyp/6-31g(d) calculation level using density functional theory (DFT) to explore the copolymerization ability of the second monomer with 1,3,5-trioxane. The results showed that CHO as the second monomer more easily participated in the copolymerization reaction, and the copolymers showed better thermal stability.

Synthesis of perfluoroalkylene-vinylene-arylene copolymers via the Mizoroki-Heck co-polymerization of 1,4-divinylperfluorobutane and 1,6-divinylperfluorohexane with dihalogenated arylene monomers

Semi-fluorinated aromatic polymers containing perfluoroalkylene [-(CF2)n-, n = 4, 6], vinylene, and arylene units in their main chains were synthesized via the Mizoroki-Heck co-polymerization of 1,4-divinylperfluorobutane and 1,6-divinylperfluorohexane with arylene monomers. The co-polymerization of 1,4-divinylperfluorobutane and 1,4-diiodobenzene was catalyzed by a ligand-less Pd(OAc)2/Bu4NBr system (“Jeffrey conditions”), while a Herrmann-type palladacycle complex (“Herrmann's catalyst”) effectively catalyzed the co-polymerization of dibrominated arylene monomers (such as 1,4-dibromobenzene). The number-average molecular weights (Mn) and weight-average molecular weights (Mw) values of the synthesized semi-fluorinated aromatic polymers were in the ranges of 2.3 × 103 to 5.4 × 103 and 3.7 × 103 to 1.1 × 104, respectively. These polymers exhibited high thermal stability, as indicated by their 5% weight loss temperatures (Td5% up to 415 °C).

Copolymerization-Regulated Hydrogen Bonds: A New Routine for High-Strength Copolyamide 6/66 Fibers.

Hydrogen bond interactions are important for nylon fibers, which improve its mechanical properties and crystallization behavior, while hindering the movement and orientation of the molecular chain during the drawn process. In this study, hexamethylene adipamide was used as the second monomer in copolymerization with ε-caprolactam to obtain copolyamide 6/66 (CoPA), and high-tenacity fibers with a maximum value up to 8.0 cN/dtex were achieved by a multi-step drawn and thermal setting process. Results show that the hexamethylene–adipamide ratio affected the draw ratio (DR) of the as-spun fiber, on the tenacity of final high-performance fiber, and on crystalline. Both DR and tenacity showed evident increases with the hexamethylene–adipamide ratio up to 6% in CoPA and then changed smoothly. However, XRD and DSC results illustrate a decreased tendency with regard to crystallinity. The attenuated in-site total reflection Fourier transform infrared (ATR-FTIR) spectra were used to study the hydrogen bond interaction between the C=O group and N–H group and the crystal form of the fiber. Results show that the copolymerization destroyed the regularity of the main chain of CoPA and reduces the interaction of interstrand hydrogen bonds, facilitating the formation of the γ-crystalline form in as-spun fibers, fulfilling the transition from the γ to α crystalline form during the fiber-drawing step because of the release of the C=O group and N–H group from the hydrogen bond interaction at an elevated temperature close to the molten temperature of CoPA, and then reforming during the thermal-setting step which soiled the crystalline and improved the tenacity of the fiber. The copolymerization with a homologous monomer regulates the hydrogen bond interaction, fulfills the high drawn ratio and high tenacity fiber, and provides a new route for high-performance fiber preparation using traditional fiber formation of polymers.

Insight into the in situ copolymerization of monomers on cement hydration and the mechanical performance of cement paste

Concrete usually possesses advantages of high compressive strength but weaknesses of low tensile strength originating from the intrinsic brittleness of cement hydrates. Here we propose a method of in situ copolymerization of monomers that use acrylic acid (AA) and acrylamide (AM) to restrain the brittleness of cement hydrates by in situ copolymerization during cement hydration and to enhance the mechanical strength of the cement matrix. Cement pastes with reinforced flexural strength and compressive strength can be obtained by modulating the fraction of AA-AM copolymer. With the polymerization reaction, a polymer skeleton was constructed in the cement matrix, followed by crosslinking with cement hydrates by the coordination between metal ions (Ca2+ and Al3+) and carboxy groups, enhancing the flexural strength and toughness of cement pastes. Our work offers a straightforward method to reduce the intrinsic brittleness of cement hydrates, providing a facile access to cementitious materials with improved flexural performance.

Development and evaluation of chitosan-g-poly(acrylic acid-co-acrylamide) hydrogel composite containing gabapentin for in vitro controlled release

In this study, a biocompatible and biodegradable hydrogel nanocomposite was synthesized through copolymerization of acrylic acid and acrylamide monomers onto chitosan in the presence of methylene bisacrylamide as a crosslinking agent and ammonium persulfate as a thermal initiator. The hydrogel was fully characterized by FTIR, SEM, DSC, and TGA techniques. The drug delivery and controlled release of gabapentin (GAB) at different pH, temperature, and time intervals were studied using the synthesized hydrogel nanocomposite. Based on the results, the maximum encapsulation and the drug loading efficiency of hydrogel composite was 64% and 71%, respectively, in which the drug was released in a sustained-release manner from the hydrogel. The release study of dual temperature and pH-responsive hydrogel composite indicated that 90% of total GAB was released from the hydrogel within the first two hours. The drug release was governed by the Higuchi kinetics model with R2= 0.9939 and followed the Fickian diffusion mechanism. The cytotoxicity of the blank hydrogel composite was evaluated on the NIH/3T3 cell line. The findings revealed that hydrogel did not affect the cells’ survival. The unique biocompatibility and thermosensitive properties of the present chitosan-based hydrogel could be a reason to use it as a promising drug carrier for the controlled and sustained release of GAB.

Effect of Fluorinated Comonomer, Polymerizable Emulsifier, and Crosslinking on Water Resistance of Latex Coatings

Common latex coatings suffer from poor water resistance, which often limits their practical application. This paper reports on the preparation of polyacrylate latexes using various approaches to tune the water resistance, wettability, and surface properties of their coating films. The mutual effects of fluorinated monomer copolymerization, emulsifier type (polymerizable and general), and intra- or interparticle covalent crosslinking (due to allyl methacrylate copolymerization and a keto-hydrazide reaction, respectively) were studied. The polyacrylate latexes were synthesized through a two-step semicontinuous emulsion polymerization of 2,2,2-trifluoroethyl methacrylate, butyl acrylate, methyl methacrylate, and methacrylic acid as the basic monomers. The fluorinated monomer was incorporated into the second-step polymer (at a content of 30 wt.% based on the second-step monomer feeds). The water resistance, wettability, and surface properties of the coating films were evaluated with focus on the water absorption, water whitening, water contact angle, and surface topography using atomic force microscopy. It was found that highly water-resistant and hydrophobic coatings that possessed a self-healing ability were prepared, provided that the polymerizable emulsifier and the fluorinated monomer were involved in the latex synthesis, along with the intra- and interparticle covalent crosslinking.

Use of Limonene Epoxides and Derivatives as Promising Monomers for Biobased Polymers.

(R)-Limonene, a renewable terpene, and its epoxidized derivatives, i. e. limonene epoxides, have prompted growing attention over the last decade as building blocks for the synthesis of biobased monomers and polymers. With the goal of replacing petroleum-based polymers several polymerization techniques have been applied on limonene oxide and limonene dioxide monomers. This paper aims to contribute to the literature by presenting a review dedicated to limonene oxide and dioxide as raw monomers of renewable origin for the development of biobased polymers. The polymerization techniques described are namely the homopolymerization, the copolymerization with carbon dioxide and anhydrides, and the copolymerization of limonene epoxide-based monomers. Limonene oxide polymerizations will be investigated first, followed by limonene dioxide polymerizations.

Functionalized poly(oligo(lactic acid) methacrylate)-block-poly(oligo(ethylene glycol) methacrylate) block copolymers: A synthetically tunable analogue to PLA-PEG for fabricating drug-loaded nanoparticles

PL(G)A-PEG block polymers have been widely used in a variety of drug delivery applications but are inherently limited in terms of their capacity for functionalization and thus customization to specific delivery tasks. Herein, we report synthetically tunable and functionalizable brush co-polymer analogues of conventional PL(G)A-PEG polymers fabricated via atom transfer radical polymerization (ATRP) of methacrylate-based co-monomers with oligo(lactic acid) side chains in the hydrophobic block and oligo(ethylene glycol) side chains in the hydrophilic block. Block co-polymers prepared by varying the molecular weights of each block, the functionality of either block (via functional monomer copolymerization), as well as the number of lactic acid repeat units in the hydrophobic block were subsequently used to fabricate nanoparticles with sizes of 100–500 nm and tunable degradation rates via flash nanoprecipitation. The resulting nanoparticles exhibited high colloidal stability (consistent with the dense brush-like POEGMA interface), favorable in vitro cytocompatibility, and the capacity for effective drug loading (>96% encapsulation efficiency for paclitaxel and 41% even for the hydrophilic therapeutic doxorubicin hydrochloride). Furthermore, functionalization of the hydrophobic POLAMA block with methacrylic acid residues enabled controlled dissolution of the nanoparticle over time, offering potential to tune drug release via an alternative mechanism not readily accessible with conventional PLA-PEG-based block copolymers. Combining these properties with the flexible chemical compositions and the generally recognized as safe degradation properties of the brush polymer analogues, POLAMA-b-POEGMA polymers represent a highly versatile platform for nanoparticle-based drug delivery applications.

Antifreezing Proton Zwitterionic Hydrogel Electrolyte via Ionic Hopping and Grotthuss Transport Mechanism toward Solid Supercapacitor Working at −50 °C

Hydrogel electrolyte is widely used in solid energy storage devices because of its high ionic conductivity, environmental friendliness, and non‐leakage property. However, hydrogel electrolyte is not resistant to freezing. Here, a high proton conductive zwitterionic hydrogel electrolyte with super conductivity of 1.51 mS cm–1 at −50 °C is fabricated by random copolymerization of acrylamide and zwitterionic monomer in the presence of 1 m H2SO4 and ethylene glycol (EG). The antifreezing performance and low temperature conductivity are ascribed to hydrogen bonds and ionic bonds between the components and water molecules in the system and can be tuned by changing the monomer ratio and EG contents. The proton hopping migration on the ionic group of the polymer chains and Grotthuss proton transport mechanism are responsible for the high proton conductivity while Grotthuss transport is dominated at the glassy state of the polymer chains. The electrolyte‐assembled supercapacitor (SC) offers high specific capacitance of 93.5 F g–1 at 25 °C and 62.0 F g–1 at −50 °C with a capacitance retention of 91.1% and 81.5% after 10 000 cycles, respectively. The SC can even work at −70 °C. The electrolyte outperforms most reported antifreezing hydrogel electrolytes and has high potential in low‐temperature devices.

Neutral Phosphine-Sulfonate Pd Complex-Catalyzed Copolymerization of 2-Methoxystyrene and Ethylene Polar Monomers: A DFT Mechanistic Study

The density functional theory (DFT) method was employed to investigate the nature of the copolymerization reaction of ethylene monomers and 2-methoxystyrene catalyzed by a palladium phosphine-sulfonate complex. The calculated results indicate that (1) the ethylene molecules prefer to coordinate with neutral phosphine-sulfonate Pd catalyst along the Pd–P side to generate an intermediate owning a cis-configuration, which indicate that the chain transfer proceeds from cis-3 but not trans-5. (2) Subsequently, the insertion of polar monomers in the chain propagation is easier than that of the ethylene monomer and adopts the 2,1 insertion pathway; meanwhile, the R-configuration pathway is more favorable than the S-configuration pathway in stage II. (3) After the polar monomer insertion, the β-H elimination pathway is easier than the ethylene insertion, which makes polar monomer insertion into the in-chain easier. This work revealed the mechanism of the copolymerization reaction of ethylene and 2-methoxystyrene catalyzed by a palladium phosphine-sulfonate complex, which could provide theoretical insights into the development of new transition-metal complexes for the copolymerization reaction.

Ionic Liquids: Emerging Antimicrobial Agents.

Antimicrobial resistance has become a serious threat to global health. New antimicrobials are thus urgently needed. Ionic liquids (ILs), salts consisting of organic cations and anions with melting points less than 100°C, have been recently found to be promising in antimicrobial field as they may disrupt the bacterial wall and membrane and consequently lead to cell leakage and death. Different types of antimicrobial ILs are introduced in the review, including cationic, polymeric, and anionic ILs. Being the main type of the antimicrobial ILs, the review focuses on the structure and the antimicrobial mechanisms of cationic ILs. The quantitative structure-activity relationship (QSAR) models of the cationic ILs are also included. Increase in alkyl chain length and lipophilicity is beneficial to increase the antimicrobial effects of cationic ILs. Polymeric ILs are homopolymers of monomer ILs or copolymers of ILs and other monomers. They have great potential in the field of antibiotics as they provide stronger antimicrobial effects than the sum of the monomer ILs. Anionic ILs are composed of existing anionic antibiotics and organic cations, being capable to enhance the solubility and bioavailability of the original form. Nonetheless, the medical application of antimicrobial ILs is limited by the toxicity. The structural optimization aided by QSAR model and combination with existing antibiotics may provide a solution to this problem and expand the application range of ILs in antimicrobial field.

Post-Modification of Copolymers Obtained by ATRP for an Application in Heterogeneous Asymmetric Salen Catalysis.

Copolymers are valuable supports for obtaining heterogeneous catalysts that allow their recycling and therefore substantial savings, particularly in the field of asymmetric catalysis. This contribution reports the use of two comonomers: Azido-3-propylmethacrylate (AZMA) bearing a reactive azide function was associated with 2-methoxyethyl methacrylate (MEMA), used as a spacer, for the ATRP synthesis of copolymers, and then post-functionalized with a propargyl chromium salen complex. The controlled homopolymerization of MEMA by ATRP was firstly described and proved to be more controlled in molar mass than that of AZMA for conversions up to 63%. The ATRP copolymerization of both monomers made it possible to control the molar masses and the composition, with nevertheless a slight increase in the dispersity (from 1.05 to 1.3) when the incorporation ratio of AZMA increased from 10 to 50 mol%. These copolymers were post-functionalized with chromium salen units by click chemistry and their activity was evaluated in the asymmetric ring opening of cyclohexene oxide with trimethylsilyl azide. At an equal catalytic ratio, a significant increase in enantioselectivity was obtained by using the copolymer containing the largest part of salen units, probably allowing, in this case, the more favorable bimetallic activation of both the engaged nucleophile and electrophile. Moreover, the catalytic polymer was recovered by simple filtration and re-engaged in subsequent catalytic runs, up to seven times, without loss of activity or selectivity.

Degradable Polystyrene via the Cleavable Comonomer Approach

Polystyrene (PS) is a major commodity polymer widely used in various applications ranging from packaging to insulation thanks to its low cost, high stiffness, and transparency as well as its relatively high softening temperature. Similarly to all polymers prepared by radical polymerization, PS is constituted of a C–C backbone and thus is not degradable. To confer degradability to such materials, the copolymerization of vinyl monomers with a cyclic monomer that could undergo radical ring-opening is an efficient method to introduce purposely cleavable bonds into the polymer backbone. Dibenzo[c,e]-oxepane-5-thione (DOT) is a cyclic thionolactone monomer known for its efficient copolymerization with acrylate derivatives but so far could not be incorporated into PS backbones. From a theoretical study combining density functional theory (DFT) and kinetic models using the PREDICI software, we showed that the modification of experimental conditions could overcome these limitations and that high molar mass degradable polystyrene (Mw close to 150 000 g·mol–1) could be prepared via statistical insertion of thioester groups into the polymer backbone. This copolymerization process is compatible with conventional free radical polymerization and reversible deactivation radical polymerization (RDRP) techniques such as nitroxide mediated polymerization (NMP). Thanks to favorable reactivity ratios allowing only a few mol % of thioester units to be randomly incorporated, there was no major modification of the thermal and mechanical properties of the PS. The degradation of such PS could be performed in tetrahydrofuran (THF) at room temperature (RT) in 1 h using 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a base, leading to oligomers with Mn close to 2000 g·mol–1. We successfully demonstrate further applicability of these copolymerization systems for the phototriggered decomposition of PS in solution as well as the synthesis of cross-linked PS networks degradable into soluble side products.

Harmonizing Topological Features of Self-Assembled Fibers by Rosette-Mediated Random Supramolecular Copolymerization and Self-Sorting of Monomers by Photo-Cross-Linking.

Random copolymerization is an effective approach to synthesize the desired polymers by harmonizing distinct properties of different monomers. For supramolecular polymers in which monomer binding is inherently dynamic, it is difficult to achieve random copolymerization of monomers with distinct molecular structures and properties due to an enthalpic advantage upon self-recognition (self-sorting). Herein, we demonstrate an example of thermodynamically controlled random supramolecular copolymerization of two monomers functionalized with barbituric acid via the formation of six-membered hydrogen-bonded rosette intermediates to exhibit structural harmonization of the two main-chain motifs, i.e., intrinsically curved and linear motifs. One monomer based on naphthalene chromophore exclusively forms toroidal fibers, whereas another one bearing additional photoreactive diacetylene moiety affords linearly elongated fibers. Supramolecular copolymerization of the two monomers is achieved by cooling hot monomer mixtures in a nonpolar solvent, which results in the formation of thermodynamically stable spirally folded yet elongated fibers. Atomic force microscopic observations and theoretical simulations of the experimental data obtained by absorption spectroscopy reveal the homopolymerization of the diacetylene-functionalized monomer in the high-temperature region, followed by the incorporation of the naphthalene monomer in the medium-temperature region to form supramolecular copolymers with random monomer sequence. Finally, we demonstrate that the random copolymerization process can be switched to a narcissistically self-sorting one by deactivating monomer exchange through the photo-cross-linking of the diacetylene-functionalized monomers.

Preparation and Characterization of Novel Microgels Containing Nano-SiO2 and Copolymeric Hydrogel Based on Poly (Acrylamide) and Poly (Acrylic Acid): Morphological, Structural and Swelling Studies.

In this paper, novel microgels containing nano-SiO2 were prepared by in situ copolymerization using nano-SiO2 particles as a reinforcing agent, nanosilica functional monomer (silane-modified nano-SiO2) as a structure and morphology director, acrylamide (AAm) as a monomer, acrylic acid (AAc) as a comonomer, potassium persulfate (KPS) as a polymerization initiator, and N,N′-methylene bis (acrylamide) (MBA) as a crosslinker. In addition, a conventional copolymeric hydrogel based on poly (acrylamide/acrylic acid) was synthesized by solution polymerization. The microgel samples, hydrogel and nanoparticles were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). A FESEM micrograph of copolymeric hydrogel showed the high porosity and 3D interconnected microstructure. Furthermore, FESEM results demonstrated that when nano-SiO2 particles were used in the AAm/AAc copolymerization process, the microstructure and morphology of product changed from porous hydrogel to a nanocomposite microgel with cauliflower-like morphology. According to FESEM images, the copolymerization of AAm and AAc monomers with a nanosilica functional monomer or polymerizable nanosilica particle as a seed led to a microgel with core–shell structure and morphology. These results demonstrated that the polymerizable vinyl group on nano-SiO2 particles have controlled the copolymerization and the product morphology. FTIR analysis showed that the copolymeric chains of polyacrylamide (PAAm) and poly (acrylic acid) (PAAc) were chemically bonded to the surfaces of the nano-SiO2 particles and silane-modified nano-SiO2. The particulate character of microgel samples and the existence of long distance among aggregations of particles led to rapid swelling and increasing of porosity and therefore increasing of degree of swelling.

Strong-Weak Response Network-Enabled Ionic Conductive Hydrogels with High Stretchability, Self-Healability, and Self-Adhesion for Ionic Sensors.

The requirement of ionic conductive hydrogels with tailor-made superelasticity and high chain mobility is highly desired while meeting a challenge. Herein, ionic conductive hydrogels with the design of strong-weak response networks were synthesized via the free-radical copolymerization of monomers of 1-methyl-3-(4-vinylbenzyl)imidazolium chloride and sodium 2-acrylamino-2-methylpropanesulfonate in water. The as-formed strong-weak response networks in ionic conductive hydrogels included binary interactions of strong electrostatic forces and weak hydrogen bonds. The electrostatic forces imparted excellent mechanical elasticity, and the hydrogen-bonded interactions served as highly active and reversible networks to dissipate fracture energy during the deformation. Importantly, the resultant ionic conductive hydrogels exhibited high toughness of ∼2205 kJ m-3, satisfying fatigue resistance, and excellent healing efficiency of >90%. Moreover, the tailoring of counterion concentrations in hydrogels by adding various concentrations of inorganic salts could regulate the electrostatic forces within hydrogels as well as the finally mechanical strengths. Ascribing to the combination of large stretchability and large chain mobility, the resultant ionic conductive hydrogels could directly act as a stretchable ionic conductor for the assembly of self-healable and self-adhesive capacitance-type ionic sensors which are capable of detecting large and tiny human activities. This study could offer a promising strategy for the design and manufacturing of emerging ionic conductors with high mechanical elasticity and large segment mobility.

Synthetic Route to Conjugated Donor-Acceptor Polymer Brushes via Alternating Copolymerization of Bifunctional Monomers.

Alternating donor–acceptor conjugated polymers, widely investigated due to their applications in organic photovoltaics, are obtained mainly by cross-coupling reactions. Such a synthetic route exhibits limited efficiency and requires using, for example, toxic palladium catalysts. Furthermore, the coating process demands solubility of the macromolecules, provided by the introduction of alkyl side chains, which have an impact on the properties of the final material. Here, we present the synthetic route to ladder-like donor–acceptor polymer brushes using alternating copolymerization of modified styrene and maleic anhydride monomers, ensuring proper arrangement of the pendant donor and acceptor groups along the polymer chains grafted from a surface. As a proof of concept, macromolecules with pendant thiophene and benzothiadiazole groups were grafted by means of RAFT and metal-free ATRP polymerizations. Densely packed brushes with a thickness up to 200 nm were obtained in a single polymerization process, without the necessity of using metal-based catalysts or bulky substituents of the monomers. Oxidative polymerization using FeCl3 was then applied to form the conjugated chains in a double-stranded (ladder-like) architecture.

Profiling protein interactions by purification with capillary monolithic affinity column in combination with label-free quantitative proteomics

An approach for profiling protein-protein interactions by using affinity purification with capillary monolithic immobilized metal affinity chromatography column (cm-IMAC) in combination with label free quantitative proteomics was described in the present work. The cm-IMAC columns were prepared in a single step by copolymerization of the function monomer, namely (S)-2,2′-((1-carboxy-5-(pent‑4-enamido)pentyl)azanediyl)diacetic acid which provide a nitrilotriacetate (NTA) moiety to form chelated complexation with Ni (II) ions, inside the fused silica capillaries. The His6-tagged bait protein can be easily immobilized on the cm-IMAC columns through the formation of chelating complexation with the NTA-Ni (II) functional groups of the matrix. The cm-IMAC columns were used to explore protein-protein interactions (PPIs) on a proteomic scale when combined with label-free proteomics. A known interaction pair of proteins, namely NDP52 (amino acid sequence 10–126) and NAP1 (33–75) as well as Bcl-2 family proteins were used for proof of concept. New interactors of Bcl-XL were identified and validated by co-immunoprecipitation.

A bioinspired sequential energy transfer system constructed via supramolecular copolymerization

Sequential energy transfer is ubiquitous in natural light harvesting systems to make full use of solar energy. Although various artificial systems have been developed with the biomimetic sequential energy transfer character, most of them exhibit the overall energy transfer efficiency lower than 70% due to the disordered organization of donor/acceptor chromophores. Herein a sequential energy transfer system is constructed via supramolecular copolymerization of σ-platinated (hetero)acenes, by taking inspiration from the natural light harvesting of green photosynthetic bacteria. The absorption and emission transitions of the three designed σ-platinated (hetero)acenes range from visible to NIR region through structural variation. Structural similarity of these monomers faciliates supramolecular copolymerization in apolar media via the nucleation-elongation mechanism. The resulting supramolecular copolymers display long diffusion length of excitation energy (> 200 donor units) and high exciton migration rates (~1014 L mol−1 s−1), leading to an overall sequential energy transfer efficiency of 87.4% for the ternary copolymers. The superior properties originate from the dense packing of σ-platinated (hetero)acene monomers in supramolecular copolymers, mimicking the aggregation mode of bacteriochlorophyll pigments in green photosynthetic bacteria. Overall, directional supramolecular copolymerization of donor/acceptor chromophores with high energy transfer efficiency would provide new avenues toward artificial photosynthesis applications.

Alleviating the trade-off interrelation between seebeck coefficient and electrical conductivity by random copolymerization of two-dimensional and one-dimensional monomers

Due to the advantages of good structural tunability, easy processibility, and high mobility, donor-acceptor based polymers are proposed as promising thermoelectric (TE) materials. However, the trade-off phenomenon between Seebeck coefficient (S) and electrical conductivity (σ) severely impedes their TE performance. Although many efforts have been applied to decouple these two parameters, it remains to be a bottleneck. Recently, we found that two-dimensional (2D) BDTTT-based polymers displayed high S with moderate σ. Combining one-dimensional (1D) conjugated structure (DPP-EDOT) with 2D conjugated structure (BDTTT-DPP) by random copolymerization can endow the polymers with good S and σ, thus alleviating the conflict. Among the polymers, P(BDTTT-DPP)1:P(DPP-EDOT)2 (P12) displayed the best power factor of 12.30 μW m−1 K−2 at room temperature, which is 4 and 1.3 times higher than that of P(BDTTT-DPP) (P10) and P(DPP-EDOT) (P01), respectively. These results provide an attractive guidance for fabricating the TE polymers with high performance by random copolymerization of two-dimensional and one-dimensional monomers.