Article
Engineering, Chemical
Dongwei Ma, Xiangyue Ye, Zhuo Li, Jiemei Zhou, Dinglei Zhong, Chenxu Zhang, Sen Xiong, Jianzhong Xia, Yong Wang
Summary: Ultrafiltration membranes derived from block copolymers with tunable pore structures and intrinsic surface functions are prepared by a simple spray-coating method. The addition of water as a pore-forming agent leads to phase separation during spray coating, resulting in the formation of nanoscale pores in the composite membranes. The membranes exhibit good ultrafiltration performance and intrinsic fouling resistance, making them comparable or better than those prepared by more complicated processes.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Chemical
Xiangyue Ye, Jiemei Zhou, Chenxu Zhang, Yong Wang
Summary: Intelligent responsive membranes have attracted much attention due to their ability to reversibly change separation performances under environmental stimulation. This study develops responsive membranes from block copolymers using CO2 gas as a stimulus. The membranes exhibit nano-porous structures and CO2-responsive chains, enabling controllable regulation of water permeance and protein separation.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Review
Chemistry, Multidisciplinary
Leiming Guo, Yong Wang, Martin Steinhart
Summary: High-performance separation membranes are crucial for ensuring sanitation in water and air, and using BCPs as a material platform is a solution to this challenge.
CHEMICAL SOCIETY REVIEWS
(2021)
Article
Polymer Science
Takahiro Sato
Summary: A lattice theory is proposed for block copolymer solutions near the boundary between the micellization and liquid-liquid phase separation regions. A new kinetic process of micellization is suggested, where small concentrated-phase droplets are first formed and then transformed into micelles in the early stage of micellization. Furthermore, a unique ripening process is observed in the late stage of phase separation, where the growing concentrated-phase droplet size is proportional to the square root of the time.
Article
Polymer Science
Wennie Yun Lee, Dana Chapman, Fei Yu, William R. T. Tait, R. Paxton Thedford, Guillaume Freychet, Mikhail Zhernenkov, Lara A. Estroff, Ulrich B. Wiesner
Summary: Self-assembled block copolymer thin films and their nanocomposites have diverse applications due to their nanostructures. Optical super-resolution microscopy (OSRM) has emerged as an alternative method for characterizing nanoscopic polymer morphology. This study focuses on self-assembled triblock terpolymer thin films with all three blocks exposed at the top surface, and demonstrates the use of OSRM for multicolor characterization of chemically distinct nanodomains.
Article
Materials Science, Composites
Qianqian Lan, Nina Yan, Hao Yang, Yong Wang
Summary: This study explores the incorporation of carbon nanotubes (CNTs) into polystyrene-block-poly (2-vinyl pyridine) (S2VP) membranes to enhance mechanical robustness and water permeance. By utilizing mild oxidation and selective swelling-induced pore generation, CNT-doped S2VP nanocomposite membranes with improved permeance and robustness were successfully prepared. The presence of CNTs in the polymer matrix resulted in membranes with excellent mechanical properties and better pressure resistance, demonstrating a simple yet efficient strategy for enhancing membrane performance.
COMPOSITES COMMUNICATIONS
(2022)
Article
Polymer Science
Kunlun Zhang, Mingheng Xiao, Li Zhang, Ying Chen, Jianbo Tan
Summary: This study reports a strategy for preparing surface-functional polymeric microspheres using photoinitiated reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization and subsequent photografting under different wavelengths of light. The method allows for the preparation of uniform-sized photoreactive polymeric microspheres and enables photografting polymerizations with various monomers. Furthermore, the technique allows for the preparation of carboxyl-functionalized polymeric microspheres, which can be extensively used for surface bioconjugation reactions.
Article
Polymer Science
Yanyan Zhu, Changhang Huang, Liangshun Zhang, David Andelman, Xingkun Man
Summary: The kinetic paths of structural evolution and formation of block copolymer (BCP) particles were investigated using dynamic self-consistent field theory (DSCFT). The study revealed that the self-assembly process of BCP in a poor solvent leads to the formation of striped ellipsoids, onion-like particles, and double-spiral lamellar particles. The shape transition between onion-like particles and striped ellipsoidal ones can be reversible by controlling the temperature and solvent selectivity. Additionally, changing the intermediate bi-continuous structure into a layered one is crucial for the formation of striped ellipsoidal particles.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Xiangjian Chen, Chuanxi Li, Yingli Ding, Yang Li, Jinshan Li, Liming Sun, Jie Wei, Xiaohui Wei, Hao Wang, Kunyu Zhang, Li Pan, Yuesheng Li
Summary: In this study, a PECH-b-PDLA diblock copolymer was prepared as an efficient compatibilizer for PLLA/CHR blends, improving the interfacial adhesion and physical properties. The optimized formulation showed significantly enhanced impact strength and elongation, being 40 times those of pure PLLA.
Article
Nanoscience & Nanotechnology
Julian Heuer, Thomas Kuckhoff, Rong Li, Katharina Landfester, Calum T. J. Ferguson
Summary: The production of photocatalytic self-assembled amphiphilic polymers enables selective control over reactions based on the substrate's physical properties. By polymerizing benzothiadiazole-based photocatalysts into hydrophilic or hydrophobic compartments, we achieved stark differences in reactivity for polar substrates but similar performance for hydrophobic substrates. Additionally, the use of secondary swelling solvents led to a significant increase in conversion for a radical carbon-carbon coupling reaction.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Polymer Science
Sudhakara Naidu Neppalli, Timothy W. Collins, Zahra Gholamvand, Cian Cummins, Michael A. Morris, Parvaneh Mokarian-Tabari
Summary: The kinetics of swelling in PS-b-PLA BCP were studied by changing the heating rate during solvo-thermal vapour annealing, showing that both solvent vapour pressure and the rate of reaching this pressure threshold significantly affect microphase separation and morphology. Highly ordered patterns are only obtained when the volume fraction of the solvent exceeds the polymer volume fraction.
Article
Spectroscopy
Jiho Kim, Wooseop Lee, Hyeji Kim, Du Yeol Ryu, Hyungju Ahn, Boknam Chae
Summary: A non-invasive, image-based analytic method using scattering-type scanning near-field optical microscopy (s-SNOM) is proposed to evaluate the phase separation behavior of lamella-forming polymer films, and the influence of self-assembly processes on the spatial distribution of polymer components is investigated.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Polymer Science
Douglas J. Grzetic, Kris T. Delaney, Glenn H. Fredrickson
Summary: Microphase separation in a binary blend of oppositely charged polymers can be stabilized electrostatically, providing a route to control microstructure. The phase behavior is affected by differences in charge density and dielectric constant of the polymers, and specific ordered phases can be stabilized when the minority component has a higher dielectric constant. This system suggests a possible route to large-unit-cell complex-sphere phases.
Review
Polymer Science
Tianyi Wang, Lei Zhong, Min Xiao, Dongmei Han, Shuanjin Wang, Zhiheng Huang, Sheng Huang, Luyi Sun, Yuezhong Meng
Summary: This review article focuses on the molecular structure-phase structure-property relationship of block copolymer electrolytes (BCPEs). By controlling the phase-separated structures, the tradeoff between mechanical strength and ionic conductivity can be decoupled. The conductivity of BCPEs is determined by the molecular structure of block copolymers and the type and concentration of additives, and the manipulation of phase-separated structures helps strengthen their mechanical support and ion transport. The article summarizes the research status and optimization strategies for BCPEs, presents methods to control the phase behavior of BCPEs, and classifies BCPEs into dual-ion conductor and single-ion conductor, analyzing their advantages and disadvantages. A design rationale for high-performance quasi-solid-state BCPEs is proposed, and polymerization methods for the regulation of molecular and phase structure are elaborated.
PROGRESS IN POLYMER SCIENCE
(2023)
Article
Engineering, Chemical
Zhenzhen Zhang, Md. Mushfequr Rahman, Ivonne Ternes, Barbara Bajer, Volker Abetz
Summary: This study reports on the development of positively charged isoporous block copolymer nanofiltration membranes with designed soft nanochannels. The membranes were obtained through self-assembly and non-solvent-induced phase separation. A versatile post-modification approach was used to engineer well-defined soft nanochannels. The membranes demonstrated the capability to separate mono-/divalent cations based on their ionic size difference, charge, and energy. The selectivity of the membranes was significantly higher in binary-salt systems compared to single-salt systems. The membranes also showed potential for recovering valuable ionic species from water, such as Mg, which is classified as a critical raw material in Europe.
JOURNAL OF MEMBRANE SCIENCE
(2024)
Article
Chemistry, Multidisciplinary
Omar Q. Imran, Na Kyung Kim, Lauren N. Bodkin, Gregory E. Dwulet, Xunda Feng, Kohsuke Kawabata, Menachem Elimelech, Douglas L. Gin, Chinedum O. Osuji
Summary: The article introduces a method of nanoscale control of self-assembled mesophase thickness through directional photopolymerization. Films prepared using highly photo-attenuating medium exhibit high resolution and water permeability. The fabricated films show superior performance compared to current state-of-the-art nanofiltration and reverse osmosis membranes.
ADVANCED MATERIALS INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Yizhou Zhang, Ruiqi Dong, Uri R. Gabinet, Ryan Poling-Skutvik, Na Kyung Kim, Changyeon Lee, Omar Q. Imran, Xunda Feng, Chinedum O. Osuji
Summary: A lyotropic liquid crystal mesophase has been developed to fabricate submicron films with 1-nm-scale pores, which exhibit excellent molecular weight cutoffs and water permeabilities, making them promising for nanofiltration applications.
Article
Chemistry, Multidisciplinary
Mingyue Yao, Baohu Wu, Xunda Feng, Shengtong Sun, Peiyi Wu
Summary: A new type of ionotronic fiber with high robustness has been designed to achieve significantly improved ionic conductivity under strain. The fiber also exhibits unique waveform-discernible strain sensing and thermal actuation properties.
ADVANCED MATERIALS
(2021)
Article
Polymer Science
Hanyu Wu, Fengxian Xu, Guanzhen Gao, Xunda Feng
Summary: A scalable strategy using photo-crosslinking of QLCs to fabricate polymeric membranes with interconnected nanopores is presented. The use of a readily synthesized zwitterionic monomer to construct G(1) mesophases enables structural lock-in. High-brilliance synchrotron small-angle X-ray scattering and transmission electron microscopy confirm the structural preservation and detailed visualization of the materials.
Article
Multidisciplinary Sciences
Jing Wang, Xudong Jiang, Hongbo Wu, Guitao Feng, Hanyu Wu, Junyu Li, Yuanping Yi, Xunda Feng, Zaifei Ma, Weiwei Li, Koen Vandewal, Zheng Tang
Summary: This study demonstrates that high voltage losses in organic solar cells can be suppressed by controlling the spacing between the donor and acceptor materials, leading to improved power conversion efficiency. Increasing the DA spacing reduces non-radiative decay of charge carriers and enhances device voltage, pointing to a new research direction for breaking the performance bottleneck of organic solar cells.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Yizhou Zhang, Dahin Kim, Ruiqi Dong, Xunda Feng, Chinedum O. Osuji
Summary: This study demonstrates a class of organic solvent-stable nanoporous membranes with tunable pore sizes and chemical structures, enabling customized selectivity and permeability.
Article
Chemistry, Multidisciplinary
Qiuya Zhang, Mengfan Lu, Hanyu Wu, Lu Zhang, Xunda Feng, Zhaoxi A. Jin
Summary: In this study, inverse micellar nanostructures with open channels were successfully generated using a modified solvent exchange method. The addition of D-tartaric acid induced the formation of mesoporous spheres with regularly packed perpendicular cylindrical channels and subsequently mesoporous spheres with gyri-like open pores. The findings provide a simple and economical pathway for fabricating hexasomes with open channels, which could be beneficial for their further applications.
Article
Chemistry, Multidisciplinary
Hanyu Wu, Hairui Huang, Yizhou Zhang, Xinglin Lu, Pawel W. Majewski, Xunda Feng
Summary: Researchers have successfully stabilized cross-linkable bicontinuous cubic liquid crystal phases and fabricated ordered polymeric materials with 1 nm channels. These materials exhibit the required mechanical integrity and chemical robustness in various organic solvents, making them suitable for practical applications in selective ion and molecule transport.
Article
Engineering, Environmental
Zimou Feng, Xunda Feng, Xinglin Lu
Summary: Inspired by osmolytes in saltwater fish, a trimethylamine N-oxide (TMAO) analog is used to construct fouling-resistant surfaces. The N-oxide monomer of methacrylamide is grafted onto filtration membrane surfaces using atom transfer radical polymerization. The modified membrane shows improved hydrophilicity, reduced charge, and decreased roughness without compromising water permeability and water-salt selectivity. The N-oxide-based polymer brushes have the potential for designing fouling-resistant surfaces for various environmental applications.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Lu Zhang, Qiuya Zhang, Hanyu Wu, Xunda Feng, Zhaoxia Jin
Summary: Interfacial engineering is crucial for controlling the self-assembly of block copolymer nanostructures during solvent exchange. In this study, the use of phosphotungstic acid (PTA) or PTA/NaCl aqueous solution as the nonsolvent led to the generation of different stacked lamellae of polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) nanostructures. The involvement of PTA in the confined microphase separation of PS-b-P2VP in droplets increased the volume fraction of P2VP and reduced the tension at the oil/water interface, while the addition of NaCl further enhanced the surface coverage of P2VP/PTA on droplets. These factors influenced the morphology of the assembled BCP nanostructures.
Article
Chemistry, Physical
Jing Wang, Cuifen Zhang, Yi Lin, Hanyu Wu, Xunda Feng, Zaifei Ma
Summary: Organic photovoltaic (OPV) devices have gained significant attention due to their ability to modify the optical properties of organic active materials, making them highly promising for efficient energy conversion even under low lighting conditions. However, the performance of OPV devices under weak illumination intensities is challenging, often leading to power conversion efficiencies below theoretical predictions. This study reveals that the restricted performance of OPV devices under weak illumination intensities is linked to substantial voltage losses, particularly nonradiative voltage losses caused by charge carrier recombination facilitated by traps. To address this concern, a two-fold strategy involving acceptor side chain modification and the utilization of a high-boiling-point solvent is proposed. By strategically modifying the molecular structure of the electron acceptor and optimizing the processing conditions of the active layer, the performance of OPV devices under low illumination intensities is remarkably enhanced, overcoming the limitations imposed by trap-assisted recombination losses and allowing efficient energy harnessing under low lighting conditions.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Hanyu Wu, Jiabin Yin, Xunda Feng
Summary: Effective retention of phosphoric acid (PA) is crucial for the efficient operation of fuel cells based on PA-doped polymeric membranes. This study reveals the remarkable capability of zwitterions to effectively sequester PA, thereby unlocking the potential for fuel cell optimization. Zwitterions exhibit stronger interactions with PA compared to traditional neutral proton-accepting bases, especially in the presence of water. The strong zwitterion-PA associations primarily arise from the formation of multiple hydrogen bonds, while the interactions between neutral bases and PA are weakened by moisture.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
