Article
Polymer Science
Gamal Zain, Maria Buckova, Katarina Mosnackova, Jana Dohanosova, Alena Opalkova Siskova, Matej Micusik, Angela Kleinova, Peter Matus, Jaroslav Mosnacek
Summary: This study reports a modification of cotton fabric surface using surface-initiated oxygen-tolerant photochemically induced atom transfer radical polymerization to impart antibacterial properties. By optimizing the reaction conditions, cotton-grafted-QPDMAEMA with high antibacterial efficiency and good laundry resistance was successfully produced. The modified fabric showed no significant deterioration in mechanical properties while maintaining high antibacterial performance.
Article
Chemistry, Multidisciplinary
Boyu Zhao, Fred Pashley-Johnson, Bryn A. Jones, Paul Wilson
Summary: This paper reports the simplified electrochemical atom transfer radical polymerization (seATRP) using Cu-II-N-propyl pyridineimine complexes for the first time. The results show that the polymerization in aqueous solution has good control over molecular weight distribution, and the polymerization process is not completely under electrochemical control. It is proposed that the seATRP using Cu-II(NPPI)2 follows an electrochemically-triggered ATRP mechanism.
Article
Polymer Science
Zahra Rostami Najafabadi, Alvaro A. Omana, Eric Rivard, Joao B. P. Soares
Summary: This study describes the synthesis of ethylene-propylene-diene terpolymers grafted with poly(methyl acrylate) (PMA) by reverse atom transfer radical polymerization, with the molecular weights and densities of PMA grafts being controlled by various factors. The grafted copolymers are characterized by different spectroscopic techniques, and copolymers with a range of graft molecular weights and densities are successfully prepared using this method.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2021)
Article
Polymer Science
Mahir Mohammed, Bryn A. Jones, Paul Wilson
Summary: Aqueous electrochemical atom transfer radical polymerisation (eATRP) has been widely used in polymer synthesis due to its excellent control and high efficiency. By leveraging recent advances, a simplified current-controlled eATRP of acrylamides in water has been developed, enabling easier operation of polymerisation reactions through a single current profile.
Article
Polymer Science
Stanislaw Sosnowski, Ryszard Szymanski, Francesca Lorandi, Mateusz Olszewski, Julian Sobieski, Rongguan Yin, Michael R. Bockstaller, Krzysztof Matyjaszewski
Summary: Numerical simulations showed that statistical copolymers with 1:1 BA/MMA composition have the highest contribution of alternating sequences, while batch ATRP of a 1:1 BA/MMA mixture generates gradient copolymers with diminished fraction of alternating sequences. A method for preparing statistical BA/MMA copolymers with the highest fraction of alternating sequences through normal ATRP copolymerization with MMA feeding was proposed to maximize the amount of alternating sequences in the copolymers.
Article
Chemistry, Multidisciplinary
Mohammad Divandari, Andrea Arcifa, Mathieu A. Ayer, Christophe Letondor, Nicholas D. Spencer
Summary: Despite advancements in low-surface energy surface fabrication, environmental consequences can be a serious issue, especially in industrial contexts.
A new fluorinated-polymer coating has been developed, applied simply from an aqueous environment, and provides an oleo/hydrophobic surface.
The coating is achieved through copolymerizing three different methacrylate monomers, each with a specific function, and treating the system with UV light to yield the desired surface properties.
Article
Chemistry, Multidisciplinary
Jie Cen, Xianjun Ye, Xiao Liu, Wenhao Pan, Lei Zhang, Guoying Zhang, Nianan He, Aizong Shen, Jinming Hu, Shiyong Liu
Summary: Amphiphilic copolypeptides containing fluorinated blocks are synthesized to stabilize gas-filled microbubbles (MBs), improving their stability and enhancing ultrasound imaging performance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Yusuke Baba, Guohao Gao, Mitsuo Hara, Takahiro Seki, Kotaro Satoh, Masami Kamigaito, Taiki Hoshino, Kenji Urayama, Yukikazu Takeoka
Summary: The study examines the impact of network structure on the mechanical properties of a polymer network. By utilizing living radical polymerization, a polymer network with a uniform structure can be obtained, leading to dried polymer networks with significantly higher fracture extensibility and energy compared to nonuniform structures obtained through conventional free-radical polymerization.
Article
Chemistry, Physical
Sajith Menon, Aravind Krishnan, Smitha Roy
Summary: The aggregation properties of diblock and triblock copolymers in the aqueous phase were investigated using photophysical and microscopy methods. Both types of copolymers form uniform spherical supramolecular assemblies in water, with the triblock copolymer containing an additional polystyrene block. Light-induced photodissociation altered the morphology of the copolymers, transforming the diblock copolymer into a double hydrophilic block copolymer and the triblock copolymer into a bolaamphiphile. Micellar dissociation was observed in the diblock copolymer, but not in the vesicular aggregates of the triblock copolymer. Additionally, aggregation resulted in pronounced excimer emission of the anthracene copolymers compared to the completely dissolved state.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Polymer Science
Maksym Odnoroh, Jean-Daniel Marty, Valerie Bourdon, Olivier Coutelier, Mathias Destarac
Summary: RAFT polymerization enables the synthesis of (co)polymers with primary benzene sulfonamide groups, using either an acrylamido sulfonamide monomer or a sulfonamide-functional trithiocarbonate RAFT agent. This research expands the possibilities for creating pH-responsive block copolymers and functional polymeric vectors with targeting properties for biomedical applications.
Article
Polymer Science
Anna Mielanczyk, Maria Kupczak, Olesya Klymenko, Lukasz Mielanczyk, Sebastian Arabasz, Krystian Madej, Dorota Neugebauer
Summary: Well-defined miktoarm star-shaped polymers and linear block copolymers have been successfully synthesized based on a heterofunctional glucose derivative initiator, N,N'-dimethylaminoethyl methacrylate (DMAEMA), using a combination of atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) techniques followed by click reactions. The presence of salts in polymer solutions affects the phase transformation and aggregate sizes, with the critical aggregation concentration (CAC) decreasing with decreasing DMAEMA unit content. TEM and AFM analysis reveal the microstructure changes in samples with different compositions of polyester arms.
Article
Chemistry, Multidisciplinary
Hyun Suk Wang, Kostas Parkatzidis, Simon Harrisson, Nghia P. Truong, Athina Anastasaki
Summary: The dispersity of a polymer is a key parameter in material design, and a rapid and quantitative method has been developed to tailor dispersity of polymers in aqueous atom transfer radical polymerization by using excess ligand to regulate the dissociation of bromide ions. This method allows for control over dispersity within a short time frame, high monomer conversions, and maintenance of high end-group fidelity.
Article
Polymer Science
Qiang Ma, Xun Zhang, Yu Jiang, Junqiang Lin, Bernadette Graff, Siping Hu, Jacques Lalevee, Saihu Liao
Summary: The development of light-mediated controlled radical polymerization has been advanced by the discovery of oxygen-doped anthanthrene (ODA) as an effective organic photocatalyst for photoinduced PET-RAFT polymerization. ODA photocatalysts feature strong visible light absorption, ease-of-synthesis, oxygen tolerance, and high stability, allowing for excellent control under extremely low catalyst loading conditions in visible light or sunlight. The organocatalytic living radical process using ODA is adaptable to a range of monomers and copolymers, and can be done under metal-free conditions.
Article
Polymer Science
Kate G. E. Bradford, Robert D. Gilbert, M. A. Sachini N. Weerasinghe, Simon Harrisson, Dominik Konkolewicz
Summary: In this study, spontaneous gradient polymerization was investigated using ATRP and RAFT methods. It was found that RAFT polymerization with a chain transfer agent (CTA) compatible with both methacrylic and acrylic monomers showed the best control over polymer structure. On the other hand, ATRP led to slightly higher dispersity polymers with decreased correlation between experimental and theoretical molecular weights. Overall, RAFT offered a simpler approach to gradient polymers when a CTA compatible with both monomers was selected.
Article
Polymer Science
James B. Young, Jared Bowman, Cabell B. Eades, Alexander J. Wong, Brent S. Sumerlin
Summary: Controlled radical polymerization techniques allow for the synthesis of polymers with specific molecular weights and architectures. In this study, the role of light in triggering thermal depolymerization of polymers synthesized through reversible-addition-fragmentation chain-transfer (RAFT) polymerization was investigated. By targeting specific electronic transitions, the depolymerization efficiency was enhanced.
Article
Nanoscience & Nanotechnology
Mikayla E. Barry, Pinar Aydogan Gokturk, Audra J. DeStefano, Amanda K. Leonardi, Christopher K. Ober, Ethan J. Crumlin, Rachel A. Segalman
Summary: Polymers are widely used in various applications that involve water exposure, and understanding the surface chemistry of polymers in these conditions is crucial. This study investigates the effects of surface-active side chains on polymer surface chemistry and water sorption using synchrotron ambient pressure X-ray photoelectron spectroscopy. The results show that different types of side chains, as well as the polymer backbone and environmental conditions, influence the water sorption behavior of the polymers.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Polymer Science
Chenyun Yuan, Florian Kafer, Christopher K. Ober
Summary: This study reports the synthesis of PGNs that can form well-defined 2D nanoparticle arrays by controlling interparticle interactions through varying grafting density. The understanding and controlling of interparticle interactions and the formations of interparticle hydrogen bonding are the motivations for potential self-assembly of PGNs and the formation of PGN superlattice structures.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Polymer Science
Tommaso J. Giammaria, Michele Laus, Riccardo Chiarcos, Christopher K. Ober, Gabriele Seguini, Michele Perego
Summary: The influence of different solvents on the self-assembly behavior of polystyrene-block-poly(dimethylsiloxane-random-vinylmethylsiloxane) diblock copolymer films was investigated. The results showed that solvent choice can substantially affect the self-assembly process and requires accurate optimization.
POLYMER INTERNATIONAL
(2022)
Article
Polymer Science
Alicia Cintora, Florian Kafer, Chenyun Yuan, Christopher K. Ober
Summary: In this study, aqueous miniemulsion polymerization based on Activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) was used to investigate the effects of hydrophobicity of monomers on dispersity, molecular weight, and particle stability. The results showed that monomers with higher hydrophobicity exhibited narrower dispersity and better control, while monomers with higher hydrophilicity led to reduced emulsion stability. This research provides insights into controlled polymerizations of hydrophilic monomers using ARGET-ATRP in miniemulsion conditions, with implications for synthesis of polymer-grafted nanoparticles with hydrophilic corona.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Amanda K. Leonardi, Riddhiman Medhi, Aria Zhang, Nilay Duzen, John A. Finlay, Jessica L. Clarke, Anthony S. Clare, Christopher K. Ober
Summary: Biofouling is a disruptive process that affects the efficiency and durability of maritime vessel coatings. This study explores the use of morpholine moieties to create amphiphilicity in a PDMS-based coating, improving its antifouling properties. Comparison with PEG controls confirms the viability of morpholine structures as alternative hydrophilic groups.
Article
Chemistry, Physical
Jingyuan Deng, Sean Bailey, Shaoyi Jiang, Christopher K. Ober
Summary: Extreme ultraviolet (EUV) lithography is currently the dominant technology in semiconductor fabrication, offering significant improvements in resolution. However, traditional chemically amplified resists (CARs) face limitations in resolution, line edge roughness, and sensitivity. A lack of understanding of the chemical mechanism associated with EUV process further hampers progress. In this study, a series of novel EUV photoresists based on a self-immolative, acid-labile poly(acetal) system were synthesized and found to be commercially viable. The study of degradation pathways led to the identification of a remarkable photoacid generator (PAG) that functions as both an acid generator and base quencher, enabling further improvements. Density functional theory calculations revealed the connection between PAG activation barrier, resist sensitivity, and the failure of electron-beam lithography in predicting EUV performance.
CHEMISTRY OF MATERIALS
(2022)
Article
Polymer Science
Gozde Aktas Eken, Florian Kaefer, Chenyun Yuan, Ivan Andrade, Christopher K. Ober
Summary: Poly(styrene-co-N-maleimide) copolymers with tert-butoxycarbonyl (t-BOC)-protected amine groups of varying side chain lengths were synthesized and studied for their applications in photoresist. The control of thermal properties and hydrophobicity through alkyl substituents allowed for well-defined line space patterns. Removal of the acid labile t-BOC group during deep-UV exposure resulted in solubility changes and promising lithographic performance in copolymers with shorter alkyl chains.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Article
Polymer Science
Gozde Aktas Eken, Christopher K. Ober
Summary: This study reports a method to prepare strong polyelectrolyte brushes with good hydration properties by controlling the alternating copolymer structures. The results demonstrate that reducing the number of charged units is an effective approach to lower the tension along the polymer chains. The study also highlights the importance of the spacers in the swelling behavior and wettability of the brushes.
Article
Polymer Science
Jingyuan Deng, Sean Bailey, Ruiwen Ai, Anthony Delmonico, Gregory Denbeaux, Shaoyi Jiang, Christopher K. Ober
Summary: Conventional chemically amplified resists (CARs) face the trade-off between resolution, line edge roughness, and sensitivity (RLS) due to acid diffusion. This study proposes an end-cap enabled chain scissionable resist based on the self-immolative property of polyphthalaldehyde (PPA) derivatives for extreme ultraviolet (EUV) lithography, and demonstrates its feasibility through experimental validation.
Article
Chemistry, Multidisciplinary
Jingyuan Deng, Sean Bailey, Shaoyi Jiang, Christopher K. Ober
Summary: A generalized synthetic approach to phthalaldehyde derivatives using sulfur(VI) fluoride exchange click chemistry has been described, enabling the tethering of virtually any non-ionic photoacid generator (PAG) to phthalaldehyde and expanding the usable chemical space. The resulting polymers represent the first PAG-tethered self-immolative resists, displaying high contrast, extraordinary sensitivity, and low roughness under extreme ultraviolet exposure.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Gozde Aktas Eken, Yuming Huang, Yixin Guo, Christopher Ober
Summary: Polyelectrolyte brushes respond to changes in pH and ionic strength and have potential for smart surfaces and surface-based sensing devices. In this study, weak acidic polyelectrolyte brushes with pH-dependent autofluorescence were developed using styrene and tailor-made N-maleimides. The brushes exhibited clusterolu-minescence due to through-space conjugation of pi-chromophoric subfluorophores. The swelling behavior of the brushes was evaluated using atomic force microscopy, and the correlation between pH-induced conformational transitions and autofluorescence was confirmed with confocal laser scanning microscopy and two-photon laser scanning microscopy.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Polymer Science
Krishnaroop Chaudhuri, Riddhiman Medhi, Zhenglin Zhang, Zhuoyun Cai, Christopher K. K. Ober, Jonathan T. T. Pham
Summary: In this study, the diffusion process of rhodamine B fluorescent dye in polystyrene-polydimethylsiloxane block copolymer coatings was visualized using confocal microscopy. The intensity of dye inside the coatings showed non-monotonic changes, attributed to concurrent dye molecule transport in different directions. An empirical fitting equation was used to compare contamination rates between copolymers, indicating that dye penetration is influenced by the chemical makeup and configuration of the BCPs. The research highlights the utility of confocal microscopy in visualizing the transport of fluorophores within coatings.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Christopher K. Ober, Florian Kafer, Chenyun Yuan
Summary: This report provides an overview of recent developments and current needs in high-resolution photopolymers and photomolecules, focusing on advancements in EUV lithography. It is part of a series of papers celebrating the centenary of the PMSE division of ACS, which has made significant contributions to semiconductor manufacturing through polymer coatings research. Only in the past 5 years has EUV lithography evolved from a future patterning method to a cutting-edge manufacturing technology, thanks to new light sources, EUV optics, tool advancements, and resist discoveries. (125 words)
Article
Nanoscience & Nanotechnology
Hadi Rahmaninejad, Andrew J. Parnell, Wei-Liang Chen, Nilay Duzen, Thomas Sexton, Gary Dunderdale, John F. Ankner, Wim Bras, Christopher K. Ober, Anthony J. Ryan, Rana Ashkar
Summary: This study investigates the gating response of nanochannels to variations in solution pH and ionic strength using selective sidewall functionalization with a polyelectrolyte brush. The conformational and structural changes of the brush layer within the channels are characterized using specular and off-specular neutron reflectometry. The results demonstrate that the brush state collapses under basic pH, representing an open gate, and expands upon decreasing pH and salt concentration, representing a partially closed gate.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Ratul Mitra Thakur, Alexandra D. Easley, Shaoyang Wang, Yiren Zhang, Christopher K. Ober, Jodie L. Lutkenhaus
Summary: This study investigates the mechanism of mixed ion-electron transfer in conjugated polymers, specifically poly(3-hexylthiophene) (P3HT), through real-time monitoring of mass changes in P3HT films. The distinct mass transfer regions are quantified as a function of doping level and potential, and their correlation with in situ conductance and spectroelectrochemical response is analyzed.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
