Article
Polymer Science
N. Lukkumanul Hakkim, Leena Nebhani
Summary: In this study, nitrone-functionalized silica derived from rice husk ash is used for polymer grafting via spin capturing and 1,3-dipolar cycloaddition reactions. The ability of the nitrone functionality to undergo 1,3-dipolar cycloaddition is verified through different experiments. The effect of silica surface area and functionalization method on polymer grafting density is studied. The results indicate the potential of nitrone functionality on solid substrates for polymer grafting.
Article
Biochemistry & Molecular Biology
Shuhong Sun, Chao Wang, Pei Zhao, Gabe M. Kline, Julia M. D. Grandjean, Xin Jiang, Richard Labaudiniere, R. Luke Wiseman, Jeffery W. Kelly, William E. Balch
Summary: Genetic variation in alpha-1 antitrypsin (AAT) leads to AAT deficiency (AATD), resulting in liver aggregation and/or insufficient AAT activity in the lung causing chronic obstructive pulmonary disease (COPD). Using Gaussian process (GP)-based machine learning, we studied the correction of AAT folding and function at a residue-by-residue level through pharmacological activation of the ATF6 arm of the unfolded protein response (UPR) using 71 AATD-associated variants. Our findings demonstrate that ATF6 activators increase AAT neutrophil elastase (NE) inhibitory activity and reduce polymer accumulation for the majority of AATD variants, including the prominent Z variant. The residue-by-residue response to ATF6 activators provides insights into the role of the gatearea in managing AAT-specific activity.
CELL CHEMICAL BIOLOGY
(2023)
Article
Polymer Science
Jiawei Chen, Wenbing Wang, Yao Pan, Dan Peng, Yougui Li, Chen Zou
Summary: In this study, direct copolymerization of plant oil-based copolymer monomers with ethylene was achieved using a dienyl phosphoribosulfonyl palladium catalyst (PO-Pd). Addition, ureido-pyrimidinone (UPy) functionalization was performed using the hydroxyl group of the polymer. The incorporation of biomass groups effectively modifies the surface and mechanical properties of the copolymers, and these newly developed polymers are ideal tougheners for gutter oil due to their excellent tunability of the self-complementary hydrogen bonding network (UPy).
Article
Engineering, Chemical
Ying Hong, Jingyuan Sun, Yao Yang, Zhengliang Huang, Jingdai Wang, Yongrong Yang
Summary: The study found that the behavior of the liquid films formed during droplet-particle collisions is more dependent on the liquid components with a higher mass fraction. The behavior of the liquid films is divided into two types, namely direct slip and recoil, with the latter enhancing heat and mass transfer efficiency. The necessary conditions for recoil are low inertia force and high temperature.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
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
Chemistry, Multidisciplinary
Shi-Yu Chen, Bai-Hao Ren, Shi-Huan Li, Yu-Hang Song, Shuang Jiao, Chen Zou, Changle Chen, Xiao-Bing Lu, Ye Liu
Summary: Transition-metal-catalyzed copolymerization produces polyketones materials with excellent properties. This study successfully synthesized a series of cationic P,O-coordinated Ni complexes catalysts with outstanding performance, which is a significant discovery in the field of Ni catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Fan Yu, Pei Li, Mengli Xu, Guoyong Xu, Yinna Na, Shaojie Zhang, Fuzhou Wang, Chen Tan
Summary: This study investigated the influence of polyethylene glycol unit on nickel-catalyzed ethylene polymerization, finding that the molecular weight of products increased with the number of oxygen atoms on the polyethylene glycol unit. The introduction of MgCl2 support resulted in higher molecular weights and lower branch densities of polymers, with heterogeneous polymerizations generating polymers with excellent powder morphology.
Article
Chemistry, Multidisciplinary
Alexander Goller, Johannes Obenauf, Winfried P. P. Kretschmer, Rhett Kempe
Summary: We reported a Coordinative Chain Transfer Polymerization catalyst for highly controlled and efficient polymerization of ethylene. The Zr catalyst demonstrated long life and temperature stability, and showed high activity with triethylaluminum as the chain transfer agent. The addition of ethylene gradually increased the chain length of the polyethylene products, and very low polydispersity was achieved with catalyst elongating alkyl chains of 60,000 or more.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Zongnan Zhang, Xinyang Li, Dezhong Zhou, Shujiang Ding, Minyan Wang, Rong Zeng
Summary: Controllable C-H bond alkylation of polyethers can be achieved under mild conditions via photoinduced iron catalysis, providing opportunities for novel applications in various research fields.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Tzu-Yao Lin, Cheng-Wei Tu, Junko Aimi, Yu-Wen Huang, Tongsai Jamnongkan, Han-Yu Hsueh, Kun-Yi Andrew Lin, Chih-Feng Huang
Summary: Reversible-deactivation radical polymerization (RDRP) was used to synthesize a series of star block copolymers, including four-arm star macroinitiators and miktoarm star copolymers. N-tert-butylmethanimine oxide was employed as an inducer in the synthesis process, and amphiphilic star block copolymers were obtained through hydrolysis reactions. Characterization and property tests revealed physical property differences between different amphiphilic mu-stars.
Article
Multidisciplinary Sciences
Haifeng Qiao, Yadav P. Kandel, John S. Van Dyke, Saeed Fallahi, Geoffrey C. Gardner, Michael J. Manfra, Edwin Barnes, John M. Nichol
Summary: Efficient information transfer between quantum systems is crucial for communication and computation, and the use of interactions and disorder can improve the quality of quantum operations. The study demonstrates enhanced quality factor in a swap operation of spin eigenstates by exploiting interactions and disorder, suggesting potential applications for non-equilibrium quantum phenomena in quantum information processing.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Applied
Hongwei Peng, Shuaikang Li, Gen Li, Shengyu Dai, Mingjun Ji, Zhe Liu, Lihua Guo
Summary: The addition of bulky rotation-restricted substituents into iminopyridyl Ni (II) and Pd (II) catalysts was shown to effectively retard chain transfer, resulting in high molecular weight polyethylene or ethylene-MA copolymers with high MA incorporation ratio. Systematic studies on the (co)polymerization behavior as a function of rotation-restricted substituent variations led to the successful synthesis of various molecular weight polyethylene and ethylene-MA copolymer products.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yang Liu, Yawei Qin, Jin-Yong Dong
Summary: The copolymerization of 1,9-decadiene/ethylene is a potential method for producing long chain-branched polyethylene using Ziegler-Natta catalysts. However, increasing the feed of 1,9-decadiene may result in gelation of the polymer.
Article
Polymer Science
Chaoqun Wang, Xiaohui Kang, Hongliang Mu, Zhongbao Jian
Summary: This study investigates the effect of polar solvents on ethylene polymerization. The results show that the use of tetrahydrofuran and 1,4-dioxane as polar solvents can increase the molecular weight, turnover frequency, and narrow the molecular weight distribution of the polymer, while maintaining the branching density. This promotes ethylene polymerization in a "living" manner and generates ultrahigh molecular weight polyethylene.
Article
Physics, Multidisciplinary
Po-Hsun Wu, Danru Qu, Yen-Chang Tu, Yin-Ze Lin, C. L. Chein, Ssu-Yen Huang
Summary: This study demonstrates the interplay of pure spin current, spin-polarized current, and spin fluctuation in 3d NixCu1-x. By exploiting the interaction of spin current with spin fluctuation in suitable Ni-Cu alloys, an unprecedentedly high spin Hall angle and spin-dependent thermal transport are achieved, which are of great significance for spintronic applications.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
N. Maximilian Bojanowski, Aleksandra Vranic, Vincent Hahn, Pascal Rietz, Tobias Messer, Julian Brueckel, Christopher Barner-Kowollik, Eva Blasco, Stefan Braese, Martin Wegener
Summary: Recent studies have introduced a new generation of photoinitiators for 3D laser nanoprinting, replacing two-photon absorption with two-step absorption. This can now be achieved using inexpensive blue laser diodes instead of expensive femtosecond laser systems. Additionally, researchers are exploring alternative photoinitiators that can be excited by one-color two-step absorption and be de-excited by a different laser color.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jochen A. Kammerer, Florian Feist, Daniel Ryklin, Abhishek Sarkar, Christopher Barner-Kowollik, Rasmus R. Schroder
Summary: It is shown that the postfunctionalization of solid polymeric microspheres can produce fully and extensively functionalized materials instead of core-shell structures. The complete functionalization is exemplified by photochemically generated microspheres, which are subsequently converted into polyradical systems. By directly visualizing the chemical distribution inside the postfunctionalized microspheres using characteristic electron energy loss signals in transmission electron microscopy (TEM), this study pioneers characterization methods with high sensitivity and resolution for all-organic low-contrast soft-matter material structures. The successful combination of ultrasonic ultramicrotomy and electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) in TEM opens up a new avenue for analyzing such structures.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Kai Mundsinger, Bryan T. Tuten, Lily Wang, Kira Neubauer, Christian Kropf, Megan L. O'Mara, Christopher Barner-Kowollik
Summary: We present a single-chain nanoparticle (SCNP) system that exhibits three times higher catalytic efficiency for the photooxidation of nonpolar alkenes compared to an equivalent concentration of small-molecule photosensitizer. The SCNP is constructed using poly(ethylene glycol) methyl ether methacrylate and glycidyl methacrylate, compacted through multifunctional thiol-epoxide ligation, and functionalized with Rose Bengal (RB). The confined RB within the SCNP achieves enhanced photocatalysis for nonpolar alkenes due to spatial proximity in the hydrophobic region.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Cameron M. Cole, Susanna V. Kunz, Thomas Baumann, James P. Blinco, Prashant Sonar, Christopher Barner-Kowollik, Soniya D. Yambem
Summary: Thermally activated delayed fluorescent (TADF) emitters are the leading materials for efficient OLEDs. A simple OLED with fully solution-processed organic layers is introduced, where the TADF emissive layer is ink-jet printed. The self-hosted TADF polymer shows potential for flexible ink-jet printed OLEDs, enabling a more scalable fabrication process.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Liang Yang, Hongrong Hu, Alexander Scholz, Florian Feist, Gabriel Cadilha Marques, Steven Kraus, Niklas Maximilian Bojanowski, Eva Blasco, Christopher Barner-Kowollik, Jasmin Aghassi-Hagmann, Martin Wegener
Summary: The authors propose laser printing as a facile process for fabricating printed electronics with minimum feature sizes below 1μm and demonstrate functional diodes, memristors, and physically unclonable functions. Laser printing with different inks, for the semiconductor ZnO and the metals Pt and Ag, is introduced for fabricating printed functional electronic devices with minimum feature sizes below 1μm. The versatility of this approach is demonstrated by showing functional diodes, memristors, and a physically unclonable function.
NATURE COMMUNICATIONS
(2023)
Article
Polymer Science
Philipp Neidinger, Dominik Voll, Sarah L. Walden, Andreas-Neil Unterreiner, Christopher Barner-Kowollik
Summary: This paper introduces the 800 nm two-photon pulsed laser polymerization (PLP) and demonstrates its working principle through biological tissue. The reliability of 2P PLP in determining propagation rate coefficients is shown using the example of the free radical polymerization of methyl methacrylate (MMA) at frequencies ranging from 10 to 100 Hz.
Article
Chemistry, Multidisciplinary
Linh Duy Thai, Thiago R. Guimaraes, Lewis C. Chambers, Jochen A. Kammerer, Dmitri Golberg, Hatice Mutlu, Christopher Barner-Kowollik
Summary: This study investigates the impact of macromolecular architecture on the isomerization efficiency of main-chain-incorporated chromophores in both solution and solid state. It is found that branched architectures deliver the highest isomerization efficiency in the solid state, reaching up to 70% compared to solution. The macromolecular design principles established in this study can serve as a blueprint for enhancing the solid-state isomerization efficiency in other polymer systems.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Ishrath Mohamed Irshadeen, Vinh X. Truong, Hendrik Frisch, Christopher Barner-Kowollik
Summary: By observing the changes in absorptivity of two chromophores upon light exposure and constructing a dual action plot, we can fold distinct polymer chains into single chain nanoparticles (SCNPs) from the same reaction mixture regardless of pathlength and wavelength-dependency.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Sebastian Gillhuber, Joshua O. Holloway, Hendrik Frisch, Florian Feist, Florian Weigend, Christopher Barner-Kowollik, Peter W. Roesky
Summary: We present a method for folding single-chain nanoparticles (SCNPs) using covalently bonded ferrocene units. In particular, we demonstrate the ability of 2-ferrocenyl-1,10-phenanthroline to induce single-chain collapse and introduce a donor functionality, allowing for the incorporation of a Pd-catalytic site. This results in the synthesis of the first heterobimetallic ferrocene-functionalized SCNP.
CHEMICAL COMMUNICATIONS
(2023)
Article
Polymer Science
Philipp Neidinger, Dominik Voll, Sarah L. Walden, Christopher Barner-Kowollik, Andreas-Neil Unterreiner
Summary: This article introduces a two-photon pulsed laser polymerization method that can penetrate through biological tissue, and demonstrates its reliability through the example of free radical polymerization of methyl methacrylate at different frequencies.
Article
Chemistry, Multidisciplinary
Rita T. Michenfelder, Laura Delafresnaye, Vinh X. Truong, Christopher Barner-Kowollik, Hans-Achim Wagenknecht
Summary: We present a visible light-driven (lambda(max) = 451 nm) photo-chemical approach for labeling DNA in living HeLa cells using the [2+2] cycloaddition reaction of a styrylquinoxaline moiety, which is incorporated into both DNA and the fluorescent label. Our methodology provides a sophisticated platform for mild remote DNA labeling in water, without the need for UV light activation.
CHEMICAL COMMUNICATIONS
(2023)
Article
Polymer Science
Alyssa J. J. Ghielmetti, Christopher Barner-Kowollik, Filip E. E. Du Prez, Hannes A. A. Houck
Summary: The molecular network connectivity in dynamic polymer networks significantly affects material properties and reprocessing conditions. The influence of regioisomerism in light-stabilized dynamic materials has been highlighted. Interchanging regioisomer fractions of substituted naphthalenes with triazolinediones (TADs) in a photo-driven cycloaddition reaction has been demonstrated to affect the cycloreversion kinetics and is important for the design of dynamic covalent materials. The development of completely regioselective TAD/naphthalene systems and the control of cycloreversion kinetics through naphthalene substitution offer new opportunities for the advancement and applications of light-stabilized dynamic materials.
Article
Polymer Science
Philipp Neidinger, Joshua Davis, Joshua A. Carroll, Jochen Kammerer, Esa Jaatinen, Sarah L. Walden, Andreas-Neil Unterreiner, Christopher Barner-Kowollik
Summary: A near infrared action plot from 620 to 950 nm for gold nanorod (AuNR) mediated free-radical polymerization is reported, probing the wavelength-by-wavelength monomer to polymer conversion with an identical number of photons at each wavelength.
Article
Chemistry, Multidisciplinary
Sarah Walden, Joshua Carroll, Andreas-Neil Unterreiner, Christopher Barner-Kowollik
Summary: This article reveals a fundamental mismatch between the absorption spectrum of a chromophore and its photochemical reactivity, highlighting the limitations of the assumption that effective photochemical reactions require strong overlap between the absorption spectrum and the excitation wavelength. The article proposes future directions for understanding action plots and explores the importance of action plots in designing precise photochemical applications.
Review
Chemistry, Multidisciplinary
Xingyu Wu, Christopher Barner-Kowollik
Summary: The development of synthetic macromolecular chemistry has made significant progress in controlling the properties of soft matter materials with molecular precision. Fluorescence-based techniques have emerged as a powerful tool for macromolecular characterization, providing detailed information and deeper insights beyond commonly used analytical methods. This article critically examines the applications of fluorescence phenomena, principles, and techniques in characterizing macromolecules and soft matter materials, highlighting recent advances and discussing future opportunities and challenges.
