Article
Chemistry, Multidisciplinary
Connor J. Stubbs, Joshua C. Worch, Hannah Prydderch, Zilu Wang, Robert T. Mathers, Andrey Dobrynin, Matthew L. Becker, Andrew P. Dove
Summary: Stereochemistry in polymers plays a significant role in controlling the mechanical and physical properties of materials. This study demonstrates that stereochemical differences in sugar-based monomers can result in a family of nonsegmented, alternating polyurethanes with exceptional properties. The behavior of these polymers is defined by distinct intra- and interchain supramolecular hydrogen-bonding interactions. The chemical similarity among these polymers allows for independent control over degradability and mechanical properties through statistical copolymerization and blending.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Marcel Eck, Lea Bernabeu, Stefan Mecking
Summary: Researchers have developed a method to make PE-18,18 hydrolytically degradable by blending it with long-chain aliphatic poly(H-phosphonate)s. The blends exhibited similar properties to HDPE and showed complete hydrolysis of the poly(H-phosphonate)s component within four months under aqueous conditions. This hydrolysis led to embrittlement and fragmentation of the specimens, promoting eventual mineralization in the environment.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Anil Kumar, Alfons R. Weig, Seema Agarwal
Summary: The study found that blends of poly(l,l-lactide) degrade faster than homopolymers, but still result in persistent microplastics in compost. Further research on the degradation of polylactide in different environmental conditions is recommended to find better solutions.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2022)
Article
Polymer Science
Stephanie F. Marxsen, Manuel Haussler, Stefan Mecking, Rufina G. Alamo
Summary: This study extends the investigation of polymorphism and crystallization kinetics of aliphatic polyacetals to include different methylene lengths, revealing the significant impact of methylene sequence length on polymorphism and crystallization kinetics. The findings show that the length of methylene groups affects the formation of different crystalline forms and influences the overall crystallization rate of the polyacetals.
Article
Polymer Science
Seo-Hwa Hong, Seok-Ho Hwang
Summary: Oligomeric polyethylene (oPE) grafted lignin improves the interfacial adhesion between lignin particles and low-density polyethylene matrix. It can serve as a biodegradable reinforcing filler and nucleating agent, enhancing the crystallization temperature and tensile characteristics of LDPE biocomposites. Additionally, oPE-g-lignin allows for the production of foams with uniform cell size distribution when used as a blowing agent.
Article
Polymer Science
C. N. Aiza Jaafar, I. Zainol, M. I. Izyan Khairani, T. T. Dele-Afolabi
Summary: The effects of filler loading and silane coupling agent on the properties of hydroxyapatite-filled high density polyethylene composites were investigated. The developed composites exhibited enhanced mechanical performance and low cytotoxicity, suggesting great potential for biomedical applications.
Article
Materials Science, Multidisciplinary
Sixi Zha, Hui-qing Lan, Nan Lin, Yueming Liu, Tao Meng
Summary: Macroscopic tensile tests are conventionally used to obtain the mechanical properties of aged polyethylene gas pipes, but fail to capture the inhomogeneous aging behavior caused by diffusion-limited oxidation. Nanoindentation procedures have been adopted to measure the time- and space-dependent mechanical properties of small-sized PE pipe samples, particularly creep properties. The combination of nanoindentation creep test and generalized Kelvin model allows for a more detailed characterization of material deformation.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Mathematics, Applied
Shaobo Gan, Fan Yang, Jiagang Yang, Rusong Zheng
Summary: In this paper, the semi-continuity of physical-like measures for diffeomorphisms with dominated splittings is considered, and it is proven that the weak-* limit of physical-like measures along a sequence of C-1 diffeomorphisms must be a Gibbs F-state for the limiting map f, leading to the establishment of statistical stability for perturbations of Lorenz attractors and continuity of physical measures for diffeomorphisms constructed by Bonatti and Viana.
Article
Engineering, Chemical
Guodong Su, Shuwei Wang, Jiangang Yu
Summary: A modified tetra-needle like ZnO whiskers filler is synthesized through a coagglomeration method, and it exhibits good activity towards ethylene polymerization, leading to enhanced thermal stability and mechanical properties of polyethylene.
POLYMER ENGINEERING AND SCIENCE
(2022)
Article
Chemistry, Physical
Rahida Wati Sharudin, Nik Salwani Md Azmi, Anuaruddin Hanizan, Suffiyana Akhbar, Zakiah Ahmad, Masahiro Ohshima
Summary: Polyethylene materials are widely used due to their advantageous characteristics, but further research is needed to improve their insulation quality and properties. In this study, the effect of modified organoclay concentration on the properties of polyethylene/organoclay nanocomposites was investigated. The concentration of organoclay influenced the crystallinity, formation of cracks, and interfacial tension of the nanocomposites.
Article
Construction & Building Technology
Safeer Ullah, Muhammad Raheel, Rawid Khan, Muhammad Tariq Khan
Summary: This study found that partially adding waste plastic aggregates in asphalt mix reduces mixture density, increases stability, flow values, and resilient modulus, but decreases dynamic modulus values with the increase in frequency.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Chemistry, Physical
Wei Zeng, Xiuqin Li, Yunyun Yang, Jian Min, Jian-Wen Huang, Weidong Liu, Du Niu, Xuechun Yang, Xu Han, Lilan Zhang, Longhai Dai, Chun-Chi Chen, Rey-Ting Guo
Summary: Polyethylene terephthalate (PET) is a widely produced plastic with high accumulation of PET wastes posing a serious threat to the ecosystem. The application of PET hydrolytic enzymes to manage PET pollution requires more effective enzymes. A thermostable cutinase called ICCG has shown to be the most effective PET hydrolase reported so far. The crystal structure of ICCG in complex with PET analogue provides insights into the enzyme-substrate interaction network and structure-based engineering has generated variants with improved efficacy and stability. These findings are valuable for understanding the mechanism of thermostable PET hydrolytic enzymes and developing PET biodegradation platforms.
Review
Chemistry, Multidisciplinary
Yi Jie Eng, Tuan Minh Nguyen, He-Kuan Luo, Julian M. W. Chan
Summary: Antifouling polymers are hydrophilic materials that can resist non-specific interactions with cells, proteins, and other biomolecules. They generate a surface hydration layer that reduces these interactions, making them valuable in nanomedicine and coatings. They play a key role in shielding drug molecules and therapeutic proteins/genes, as well as preventing cell and molecule adhesion, enabling effective delivery and surface protection.
Review
Chemistry, Multidisciplinary
Yi Jie Eng, Tuan Minh Nguyen, He-Kuan Luo, Julian M. W. Chan
Summary: Antifouling polymers are hydrophilic materials that can resist nonspecific interactions with cells, proteins, and other biomolecules. They play a key role in nanomedicine and surface modification applications.
Article
Chemistry, Multidisciplinary
Dingling Zhong, Shiyang Shi, Xiaolong Yang, Stephan Handschuh-Wang, Yaokang Zhang, Tiansheng Gan, Xuechang Zhou
Summary: This study presents a facile synthesis of liquid metal-polymer composites with high electrical conductivity, high stretchability, degradability, and recyclability. The composite consists of a physically crosslinked poly(2-hydroxyethyl acrylate) hydrogel as a polymer matrix and liquid metal nanodroplets or silver microflakes as conductive fillers.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Fei Lin, Stefan Mecking
Summary: In this study, water-soluble synthetic transition metal catalysts were synthesized for olefin polymerization. The nickel catalysts with hydrophilic active sites demonstrated high activity and produced high molecular weight polyethylene in aqueous conditions, even at elevated temperatures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Benjamin A. Paren, Manuel Haeussler, Patrick Rathenow, Stefan Mecking, Karen Winey
Summary: We have presented a set of sulfonated monodisperse telechelic polyethylene ionomers that demonstrate ion transport of metal cations in layered ionic assemblies. These polymers have well-defined structures and exhibit different crystal packing and ion transport properties at different temperatures.
Article
Chemistry, Multidisciplinary
Jinseok Park, Anne Staiger, Stefan Mecking, Karen I. Winey
Summary: This study demonstrates that ionic functionality in a multiblock architecture can produce highly ordered nanostructures in thin films, including bicontinuous double gyroids. The researchers propose a versatile pathway to fabricating ordered nanostructures in thin films using ion-functionalized multiblock copolymers.
ACS CENTRAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Lukas Odenwald, Florian P. Wimmer, Nina K. Mast, Max G. Schussmann, Manfred Wilhelm, Stefan Mecking
Summary: Vitrimers combine the advantages of cross-linked materials with thermoplastic processability. Functionalized polyethylenes with cross-linkable groups were directly generated by catalytic insertion polymerization. These vitrimers exhibit excellent material properties and can be recycled due to reversible cross-linking.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Maria Voccia, Lukas Odenwald, Maximilian Baur, Fei Lin, Laura Falivene, Stefan Mecking, Lucia Caporaso
Summary: Polyethylene materials with in-chain-incorporated keto groups can be achieved by nonalternating copolymerization of ethylene with carbon monoxide using Ni(II) phosphinephenolate catalysts. The mechanism of this reaction involves the isomerization of an alkyl-olefin intermediate as the rate-determining step. The formation of non-alternating incorporation is influenced by ethylene binding, while the formation of alternating motifs is determined by the opening of the C,O-chelate. The crucial feature of these Ni(II) catalysts is the eta(2)-coordination of a P-bound aromatic moiety axially oriented to the metal center, which also affects the competition between the two pathways. The conformational constraints imposed in a 2',6'-dimethoxybiphenyl moiety result in disfavoring ethylene coordination along the alternating incorporation pathway, primarily governed by electronics, while not penalizing the nonalternating chain growth, primarily governed by sterics.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Amelie Fuchs, Stefan Mecking
Summary: This study reports an organometallic-mediated radical copolymerization method for carbon monoxide and ethylene, leading to the synthesis of keto-modified polyethylenes. The presence of carbon monoxide enhances the controlled character of the copolymerization by suppressing unfavorable termination pathways.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Polymer Science
Maximilian Baur, Stefan Mecking
Summary: Linear polyethylenes with incorporated in-chain keto and side-chain ester groups are formed by Ni(II)-catalyzed terpolymerization of ethylene, carbon monoxide, and methyl acrylate. These polymers possess a random structure while retaining the solid-state structure of polyethylene.
Article
Chemistry, Multidisciplinary
Marcel Eck, Simon Timm Schwab, Taylor Frederick Nelson, Katrin Wurst, Steffen Iberl, David Schleheck, Christoph Link, Glauco Battagliarin, Stefan Mecking
Summary: We have developed a new polyester material using biobased 1,18-octadecanedicarboxylic acid and ethylene glycol, which has a solid-state structure similar to polyethylene and comparable tensile properties to high density polyethylene (HDPE). Despite its crystallinity, high melting point and hydrophobic nature, the polyester-2,18 can be rapidly and completely hydrolytically degraded in vitro by naturally occurring enzymes. It also shows high biodegradability under industrial composting conditions and can be depolymerized by methanolysis for closed-loop recycling.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Stefanie de Roo, Felix Einsiedler, Stefan Mecking
Summary: This study demonstrates the catalytic conversion of renewable plant oils, including microalgae and waste oil, into industrially relevant alpha-olefins in the C-3 to C-10 regime. The biorefinery concept involves a catalytic sequence of ethenolysis, double bond isomerization, and subsequent ethenolysis, effectively rearranging the fatty acid chains into valuable chemical building blocks. Supercritical carbon dioxide (scCO(2)), a benign extraction and reaction solvent, is utilized.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Marcel Eck, Lea Bernabeu, Stefan Mecking
Summary: Researchers have developed a method to make PE-18,18 hydrolytically degradable by blending it with long-chain aliphatic poly(H-phosphonate)s. The blends exhibited similar properties to HDPE and showed complete hydrolysis of the poly(H-phosphonate)s component within four months under aqueous conditions. This hydrolysis led to embrittlement and fragmentation of the specimens, promoting eventual mineralization in the environment.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Maximilian Baur, Nina K. Mast, Jan P. Brahm, Rosa Habe, Tobias O. Morgen, Stefan Mecking
Summary: In this study, we modified polyethylene using both ketone and ester functional groups, and found that the simultaneous presence of both groups has no adverse effects on the crystal structure and thermal properties of polyethylene. Through oxidation of the in-chain ketone groups, high molecular weight polyethylenes with in-chain ketone-ester groups can be synthesized, which exhibit good photolytic degradation and chemical recyclability. We also demonstrated that polyethylenes bearing in-chain ketone groups can be produced via post-polymerization Baeyer-Villiger oxidation, combining the photodegradability of ketones with the chemical access point of esters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Taylor F. Nelson, Dario Rothauer, Michael Sander, Stefan Mecking
Summary: Monomers sourced from waste or biomass, such as polyethylene waste or bio-based fatty acids, can be used to synthesize polyesters with various chain lengths. These polyesters exhibit high-density polyethylene-like properties, are ductile, and can be processed into films and fibers. They also show potential for chemical recycling or biodegradation in the environment.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Frieder Conradt, Vincent Bezold, Volker Wiechert, Steffen Huber, Stefan Mecking, Alfred Leitenstorfer, Ron Tenne
Summary: This study demonstrates the causal link between the quantum-confined Stark effect and spectral diffusion, and reveals the relation between the sensitivity of transition energy to an electric field and amplified spectral fluctuations. This is important for overcoming the critical barrier in applications of quantum sensing.
Article
Polymer Science
Stephanie F. Marxsen, Manuel Haeussler, Marcel Eck, Stefan Mecking, Rufina G. Alamo
Summary: In this study, the isothermal overall crystallization rates and linear growth rates of four symmetric long-spaced aliphatic polyesters were investigated. It was found that the polyesters exhibited discrete rate minima with increasing crystallization temperature, and the number and depth of these minima depended on the length of the methylene spacer between esters. The occurrence of rate minima could be explained by the self-poisoning feature and the difference in crystal thickness between non-integer and integer layered crystals.
Article
Chemistry, Multidisciplinary
Anne Saumer, Stefan Mecking
Summary: We report the synthesis and properties of ion-containing, long-chain aliphatic polyesters that can be degraded and fully recycled. These polyesters exhibit desirable traits, such as adhesion with polar compounds, due to the presence of ionic groups. The mechanical properties and melt rheology of these polyesters are significantly influenced by the nature of the cation counterions. Additionally, these polyesters can be chemically recycled by depolymerization. Our findings provide opportunities for tuning the properties of recyclable polyethylene-like polymers.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Xuemei Liu, Chaonan Cui, Shuoshuo Wei, Jinyu Han, Xinli Zhu, Qingfeng Ge, Hua Wang
Summary: This study presents a new strategy for designing efficient photocatalysts that can convert CO2 into hydrocarbons by utilizing synergistic catalytic sites. The findings provide a solution for the selective photocatalytic reduction of CO2 to CH4.
Article
Chemistry, Multidisciplinary
Chengxian Hu, Dan Wang, Lu Wang, Ying Fu, Zhengyin Du
Summary: A novel one-pot, three-component reaction conducted under electrochemical conditions was studied. The reaction involved 2-aminothiophenols, aldehydes, and malononitrile, using TBABF4 as an electrolyte and CuI as a catalyst. The proposed reaction mechanism suggested that CuI served as an electron relay. This method offers simplified operation, high atom economy, and mild reaction conditions.
Article
Chemistry, Multidisciplinary
Zhi Yang, Yu Chen, Linxi Wan, Yuxiao Li, Dan Chen, Jianlin Tao, Pei Tang, Fen-Er Chen
Summary: A highly enantioselective method for the complete hydrogenation of pyrimidinium salts using Ir/(S,S)-f-Binaphane complex as the catalyst was developed. This method provides easy access to fully saturated chiral hexahydropyrimidines, which are prevalent in many bioactive molecules. The reactions exhibit high yields and enantioselectivities under mild reaction conditions without additives. Successful application of this methodology in a continuous flow fashion further extends its practical utility.
Article
Chemistry, Multidisciplinary
Tina Jeoh, Jennifer Danger Nill, Wujun Zhao, Sankar Raju Narayanasamy, Liang Chen, Hoi-Ying N. Holman
Summary: In this study, the enzymatic hydrolysis of cellulose was investigated using real-time infrared spectromicroscopy. The spatial heterogeneity of cellulose was found to impact the hydrolysis kinetics. Hydration affected cellulose ordering, and Cel7A preferentially removed less extensively hydrogen bonded cellulose.
Article
Chemistry, Multidisciplinary
Tiphaine Richard, Walid Abdallah, Xavier Trivelli, Mathieu Sauthier, Clement Dumont
Summary: An effective method of grafting functionalities onto lignin based on glycerol carbonate has been developed using an efficient nickel-catalysed telomerisation reaction. This method allows lignin to have new reactive functions and reduces the glass transition temperatures of modified lignins, thereby expanding the application range of lignin-based resins.
Article
Chemistry, Multidisciplinary
Jing Qi, Xiyan Wang, Gan Wang, Srinivas Reddy Dubbaka, Patrick ONeill, Hwee Ting Ang, Jie Wu
Summary: This study presents a green and environmentally friendly approach for the synthesis of imides using electrocatalytic oxidation with H2O as the oxygen source. The method eliminates the need for toxic or expensive oxidants and achieves high yields under mild reaction conditions. It shows broad substrate compatibility and potential for industrial applications.
Article
Chemistry, Multidisciplinary
Babasaheb Sopan Gore, Lin-Wei Pan, Jun-Hao Lin, Yi-Chi Luo, Jeh-Jeng Wang
Summary: Here, we report a visible light-promoted intramolecular radical cascade reaction for the construction of fluorenol and naphthalene-fused cyclopropyl carbaldehyde derivatives. This method offers mild reaction conditions, a broad substrate scope, excellent step efficiency, and scalability, without the need for external chemical oxidants. The novelty of this protocol was demonstrated by synthesizing chrysene analogs and performing late-stage functionalizations.
Article
Chemistry, Multidisciplinary
Juho Antti Sirvio, Idamaria Romakkaniemi, Juha Ahola, Svitlana Filonenko, Juha P. Heiskanen, Ari Ammala
Summary: This article discusses the method of using supramolecular interaction between an aromatic hydrogen bond donor and lignin to achieve rapid delignification of softwood at low temperatures.
Article
Chemistry, Multidisciplinary
Yunyan Meng, Chunxiang Pan, Na Liu, Hongjiang Li, Zixiu Liu, Yao Deng, Zixiang Wei, Jianbin Xu, Baomin Fan
Summary: A novel visible light-driven synthesis method for 2,3-diamines has been developed, which has mild conditions, avoids the use of metal reagents, and can synthesize diamines and diols in one pot.
Article
Chemistry, Multidisciplinary
Mingqing Huang, Haiyang Huang, Mengyao You, Xinxin Zhang, Longgen Sun, Chao Chen, Zhichao Mei, Ruchun Yang, Qiang Xiao
Summary: A direct air-oxidized strategy for the synthesis of benzo[b]phosphole oxides was developed in this study. Arylphosphine oxides were transformed into phosphinoyl radicals, which were further combined with various alkynes to achieve the desired products. DFT calculations revealed the mechanism of phosphinoyl radical formation.
Article
Chemistry, Multidisciplinary
Anwei Wang, Jiayin Huang, Chunsheng Zhao, Yu Fan, Junfeng Qian, Qun Chen, Mingyang He, Weiyou Zhou
Summary: This study demonstrates an innovative strategy for the aerobic oxidation of C(sp(3))-H bonds using gamma-valerolactone. By optimizing the reaction conditions and utilizing specific catalysts, efficient oxidation of C(sp(3))-H bonds is achieved with good chemoselectivity in certain cases.
Article
Chemistry, Multidisciplinary
Shun Li, Likai Tong, Zhijian Peng, Bo Zhang, Xiuli Fu
Summary: Sulfide compounds show promise as electrocatalysts for water splitting, but their performance is limited by factors such as limited active sites and hindered substance transport. This study successfully prepared a high-entropy sulfide (ZnCoMnFeAlMg)(9)S-8, which reduced grain size and increased specific surface area, enabling the realization of a dual-functional catalyst with multiple catalytic sites. High entropy also modulated the electronic properties of sulfides, reducing the potential energy barrier for hydrolysis. This research introduces a new approach for functionalizing high entropy nanomaterials and improves the performance of water splitting catalysts.