Article
Polymer Science
Francis McCallum, Jiacheng Zhao, Md. Daloar Hossain, Joshua A. Kaitz, James F. Cameron, Peter Trefonas III, Idriss Blakey, Hui Peng, Andrew K. Whittaker
Summary: Block copolymer (BCP) self-assembly is a promising method for generating features for integrated circuits and memory devices. However, it is challenging to select a common good solvent for high-x BCPs and control the alignment of phase separated morphologies. In this study, we synthesized a series of BCPs and demonstrated the ability to switch between different morphologies and achieve lamellar patterning with domains as small as 14 nm on a wafer.
Article
Chemistry, Multidisciplinary
Tandra Ghoshal, Timothy W. Collins, Subhajit Biswas, Michael A. Morris, Justin D. Holmes
Summary: Nanopatterns can be formed by annealing block copolymers in organic solvents, but a more environmentally friendly method is to anneal them in supercritical carbon dioxide. This method can achieve well-defined, hexagonally ordered films of line and hole patterns at low temperatures and pressures.
Article
Engineering, Chemical
Qin Wu, Yan Sun, Wei Wang, Shuyao Tian, Mengjie Ouyang, Kangcheng Chen, Daxin Shi, Yaoyuan Zhang, Hansheng Li, Zhiping Zhao
Summary: A series of multiblock polydimethylsiloxane-b-polyimides copolymers were successfully prepared and their physicochemical properties, pervaporation properties, and thermal stability were studied. The results showed that the mechanical properties and swelling behavior of the membranes varied with different compositions of the copolymers.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Juan Zhang, Andrew N. Keith, Sergei S. Sheiko, Xuehui Wang, Zhigang Wang
Summary: In order to mimic the mechanical behaviors of skin, a reprocessable bottlebrush copolymer elastomer was designed with renewable and rigid cellulose as backbones, while poly(n-butyl acrylate)-b-poly(methyl methacrylate) (PBA-b-PMMA) diblocks were designed as grafted side chains. The resulting elastomers underwent a step-cyclic tensile deformation, leading to internal structures becoming oriented nanofibers and exhibiting stress-strain behaviors similar to real skin. Our current research work is expected to be important in the development of a series of biomimetic skinlike polymer materials.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Hoang M. Nguyen, Ariane V. Mader, Swarnalok De, Jaana Vapaavuori
Summary: The effect of dip-coating parameters on the morphology evolution of BCP thin films was studied, obtaining a hexagonally packed BCP pattern with long-range order without the need for post-annealing processes. This study extends the understanding of the parameters affecting the formed surface patterns and their interplay to more materials.
NANOSCALE ADVANCES
(2021)
Article
Chemistry, Multidisciplinary
Jie Cui, Entian Liu, Tongjing Song, Yuanyuan Han, Wei Jiang
Summary: In this study, rectangular cylinders self-assembled by compositionally bidisperse ABC triblock terpolymer blends were investigated via numerical simulations. The simulation results revealed that the selective aggregation of the short side blocks determines the formation of the rectangular cylindrical phase, expanding the parameter window of the rectangular cylinders by increasing the chain length fraction of the middle B blocks. These simulation works can provide a theoretical basis for molecular design to regulate and fabricate nanomaterials with nontraditional phase domains in future experiments.
Article
Polymer Science
Changyeon Lee, Chinedum O. Osuji
Summary: Liquid-crystal polymers combine the characteristics of liquid crystals and polymers, exhibiting intriguing physical phenomena and useful properties. Over the past nearly 50 years, there has been significant expansion in the field, with developments in new chain architectures, new classes of mesogens, and exploration of new properties and applications. Opportunities for LCPs, particularly in nanopatterning and beyond, are emerging with the ability to access small feature sizes and fluidity of the LC mesophase presenting compelling possibilities for orientation control.
Article
Engineering, Chemical
Ki Jung Kim, Yunmi Chae, Seong Jin An, Jin Hui Jo, Sungmin Park, Won Seok Chi
Summary: This study investigates microphase-separated structured PI-POEM graft copolymer membranes, which have controllable POEM concentrations and the ability to modify material properties. The results show that PI-POEM graft copolymer membranes exhibit high CO2 affinity and separation performance, making them promising for CO2 separation processes.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Polymer Science
Moritz Meier-Merziger, Marcel Fickenscher, Frank Hartmann, Bjoern Kuttich, Tobias Kraus, Markus Gallei, Holger Frey
Summary: Bifunctional initiators were used to synthesize complex triblock copolymer structures in carbanionic polymerization. Isoprene was polymerized using 1,3-bis(1-phenylethenyl)benzene (PEB), resulting in a high content of 93% 1,4-PI units. Hydroxyl groups were then introduced simultaneously in the alpha- and omega-position using end-functionalization of the living anionic di-lithiated polyisoprene (PI) chains with 1,2-isopropylidene glyceryl glycidyl ether (IGG) and subsequent acidic deprotection. The resulting hexa-hydroxy functional PI-macroinitiators were used to initiate l-lactide (LLA) polymerization, leading to the formation of super-H-shaped (PLLA)(3)-b-PI-b-(PLLA)(3) triblock structures with narrow molecular weight distributions.
Article
Chemistry, Multidisciplinary
Kevin Ho, Kris S. Kim, Sissi de Beer, Gilbert C. Walker
Summary: Investigations on the transitional composition between two thin-film morphologies of the block copolymer, polystyrene-block-poly(tert-butyl acrylate) (PS-b-PtBuA), were conducted using near-field infrared spectroscopy and atomic force microscopy mechanical measurements. The techniques allowed for block identification with nanoscale spatial resolution and elucidated the material's sub-surface composition, revealing distinct patterns of PS and PtBuA formation in different regions of the polymer film.
Article
Polymer Science
I-Ming Lin, Chih-Chiang Hsu, Tsung-Chun Yu, Shiao-Wei Kuo, Wei-Tsung Chuang, Yeo-Wan Chiang
Summary: Nanohybrid materials with a hierarchical or homogeneous phase have been designed by controlling host-guest and guest-guest interactions, allowing for controlled formation and distribution of nanosheets.
Review
Instruments & Instrumentation
Qinqin Zhang, Xiaoqi Lin, Weisheng Chen, Kaisen Jiang, Dezhi Han
Summary: Polyurethanes (PUs) are widely used for their versatile properties of elasticity and hardness, usually with microphase-separated structures. Characterization methods such as FTIR, AFM, DSC, and SAXS are used to study these structures and their relationship with PU properties, laying a theoretical foundation for improving PU application performance.
APPLIED SPECTROSCOPY REVIEWS
(2022)
Article
Polymer Science
Thomas Kinsey, Emmanuel Urandu Mapesa, Weiyu Wang, Kunlun Hong, Jimmy Mays, S. Michael Kilbey, Joshua Sangoro
Summary: The study investigated the impact of architectural asymmetry on the dielectric polymer relaxations in miktoarm star copolymers using broad-band dielectric spectroscopy and small-angle X-ray scattering. It was found that architecturally asymmetric systems exhibited distributions in relaxation times and strengths that were not dependent on molecular weight or morphology, contrasting with the effects observed in symmetric diblock systems. The results suggest that molecular architecture in block copolymers can serve as a versatile tool to control polymer chain dynamics and macroscopic properties.
Review
Polymer Science
Polyxeni P. Angelopoulou, Ioannis Moutsios, Gkreti-Maria Manesi, Dimitri A. Ivanov, Georgios Sakellariou, Apostolos Avgeropoulos
Summary: This review article discusses the origins of self-assembly behavior of linear and non-linear block co-and terpolymers and their application towards the fabrication of high-resolution patterns for nanolithography applications. Comparative analysis for the microphase separation in bulk and thin films is provided, to map the fundamentals of various types of block copolymers (BCPs) inherent properties prior to their use in advanced applications. The opportunities of high-chi/low-N and/or complex architecture co-and terpolymers to self-assemble into nanostructures that are beyond the limitations of current lithographic techniques will be presented. The role of molecular characteristics and immiscibility of the blocks on the formation of sub-10 nm or sub-5 nm structures will be discussed. Recent advances in directed self-assembly (or DSA) enable low defect density, extremely minimal dimensions, facile processability, etching selectivity, low-cost and ability to design various patterns. The opportunities of these strategies will be discussed in the context of technological standard requirements and their potential will be evaluated.
PROGRESS IN POLYMER SCIENCE
(2022)
Review
Materials Science, Multidisciplinary
Feng Cai, Bowen Yang, Mingming Yu, Songshan Zeng, Haifeng Yu
Summary: Photocontrollable liquid-crystalline block copolymers have shown remarkable light-response properties due to their unique combination of mesogenic ordering and microphase-separated nanostructures. However, their current structure design and performance still need improvement, limiting their further potential applications. Recent progress in photocontrollable liquid-crystalline block copolymers is summarized, focusing on their photoresponsive mechanisms, alignment techniques, and potential applications in various fields. Challenges and prospects in this field are also discussed.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Valeria Castelletto, Ian W. Hamley
Summary: It has been demonstrated that a conserved coronavirus spike protein peptide can form amyloid structures, which has implications for the stability of the spike protein conformation and potential functional material applications.
Article
Chemistry, Multidisciplinary
Lucas R. de Mello, Vinicius Carrascosa, Eduardo Rebelato, Maria A. Juliano, Ian W. Hamley, Valeria Castelletto, Sandra V. Vassiliades, Wendel A. Alves, Clovis R. Nakaie, Emerson R. da Silva
Summary: Peptide-based hydrogels are promising biomaterials that can mimic the 3D microenvironment of the extracellular matrix. This study demonstrates that a synthetic decapeptide can form highly stable hydrogel matrices that retain a high water content and induce morphogenesis in interacting cells.
Article
Biochemistry & Molecular Biology
Elisabetta Rosa, Lucas de Mello, Valeria Castelletto, Mark L. Dallas, Antonella Accardo, Jani Seitsonen, Ian W. Hamley
Summary: This study investigates the conformation and self-assembly behavior of four lipopeptides, and examines their potential applications in tissue engineering based on cytocompatibility assessments. The results show that all four lipopeptides can self-assemble into nanostructures at specific concentrations. Furthermore, these lipopeptides demonstrate promising prospects in tissue engineering.
Article
Chemistry, Multidisciplinary
Nada Aljuaid, Jani Seitsonen, Janne Ruokolainen, Francesca Greco, Ian W. Hamley
Summary: This study found that analogues of benzene-1,3,5-tricarboxamide can self-assemble into micelles or nanotapes in aqueous solution, depending on the architecture of alkyl and PEG chains. The compounds exhibit selective cytotoxicity to breast cancer cells, showing strong stability in acidic tumor conditions and cell culture media.
Review
Nanoscience & Nanotechnology
Ian W. Hamley
Summary: This review focuses on the self-assembly, structural and functional properties of peptide conjugates containing bulky terminal aromatic substituents, with a particular emphasis on bioactivity. The driving force for self-assembly comes from pi-stacking and hydrophobic interactions, as well as hydrogen bonding, electrostatics, and other forces between short peptides. The balance of these interactions leads to a propensity for self-assembly, even for single amino acid conjugates. The resulting molecules often form hydrogels built from beta-sheet fibrils, with applications in biomaterials, drug delivery, catalysis, and optoelectronics.
ACS APPLIED BIO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Valeria Castelletto, Jani Seitsonen, Ian W. W. Hamley
Summary: This study investigates the self-assembly behavior of two monodisperse lipid A derivatives based on bacterial LPS structures in water and compares them to native Escherichia coli LPS using small-angle X-ray scattering and cryogenic transmission electron microscopy. The critical aggregation concentration and conformation are characterized using fluorescence probe experiments and circular dichroism spectroscopy, respectively. The E. coli LPS forms wormlike micelles, while the synthetic analogues self-assemble into nanosheets or vesicles depending on the number of lipid chains and saccharide head groups. These findings can be rationalized based on the surfactant packing parameter.
Article
Chemistry, Multidisciplinary
Biswanath Hansda, Jhilam Majumder, Biplab Mondal, Akash Chatterjee, Subhadeep Das, Sourav Kumar, Ratan Gachhui, Valeria Castelletto, Ian W. Hamley, Prosenjit Sen, Arindam Banerjee
Summary: A histidine-based amphiphilic peptide (P) was discovered to form an injectable transparent hydrogel with inherent antibacterial property in phosphate buffer solution. The peptide self-assembles into a nanofibrillar network structure and exhibits efficient antibacterial activity against both Gram-positive and Gram-negative bacteria. The hydrogel can also encapsulate and selectively release drugs, making it a potential antibacterial and drug delivering agent.
Article
Biochemistry & Molecular Biology
Valeria Castelletto, Lucas de Mello, Emerson Rodrigo da Silva, Jani Seitsonen, Ian W. Hamley
Summary: Considerable interest has been shown in peptides with the Fmoc protecting group, as it can promote self-assembly and has applications in cell culture biomaterials. New amino acid analogues with the Smoc protecting group have been developed for water-based peptide synthesis. Self-assembly of Smoc-Ala, Smoc-Phe, and Smoc-Arg occurs above the critical aggregation concentration (CAC) and forms nanosheet, nanoribbon, or nanotube structures. Smoc-amino acids show excellent biocompatibility and are taken up by fibroblast cells without cytotoxicity.
Article
Chemistry, Physical
Thiago C. Lourenco, Lucas R. de Mello, Marcelo Y. Icimoto, Renata N. Bicev, Ian W. Hamley, Valeria Castelletto, Clovis R. Nakaie, Emerson R. da Silva
Summary: This study presents a strategy for fabricating highly ordered 1D nanostructures of Bradykinin (BK) using DNA fragments as a template for self-assembly. The nanoscale structure of BK-DNA complexes was revealed, showing the formation of ordered nanofibrils. The complexes retained the native bioactivity of BK and could induce a limited uptake of nucleotides by HEK-293t cells, which has not been previously reported.
Article
Chemistry, Physical
Elisabetta Rosa, Carlo Diaferia, Lucas De Mello, Jani Seitsonen, Ian W. Hamley, Antonella Accardo
Summary: Short and ultra-short peptides are now being used as building blocks for self-assembled materials, with peptide aggregation being influenced by the amino acids in the sequence as well as their ability to interact with each other. By modifying peptides with polymeric moieties, alkyl chains, or other organic molecules, further structural and functional properties can be achieved. In this study, we synthesized and investigated the aggregation behavior of peptide amphiphiles (PAs) containing cationic tetra- or hexa-peptides derivatized with an alkyl chain. These PAs were able to form highly ordered nanostructures and biocompatible hydrogels, showing potential for tissue engineering and diagnostic applications.
Article
Chemistry, Physical
Jinghua Liu, Jingqing Li, Binyuan Liu, Ian W. Hamley, Shichun Jiang
Summary: The Mpemba effect and its inverse can be explained by nonequilibrium thermodynamics. While changes of state in polymers are generally non-equilibrium processes, the Mpemba effect is rarely seen in their crystallization. Polybutene-1 (PB-1) has the lowest critical cooling rate among polyolefins and tends to maintain its original structure and properties in the melt. Experimental observations confirm the presence of the Mpemba effect in both the crystallization of PB-1 in form II and form I obtained at low melting temperatures.
Article
Chemistry, Physical
Biswanath Hansda, Biplab Mondal, Soumyajit Hazra, Krishna Sundar Das, Valeria Castelletto, Ian W. Hamley, Arindam Banerjee
Summary: Peptide-based multicomponent hydrogels offer tunable mechanical properties and physical characteristics, demonstrating good cell compatibility and sustained drug release capabilities, and have the potential to serve as scaffold materials for tissue engineering.
Article
Chemistry, Physical
Biplab Mondal, Vivek Kumar Gupta, Biswanath Hansda, Arpita Bhoumik, Tanushree Mondal, Hemanta K. Majumder, Charlotte J. C. Edwards-Gayle, Ian W. Hamley, Parasuraman Jaisankar, Arindam Banerjee
Summary: Nanoscale self-assembly of peptide constructs is a promising approach for developing functional materials with bioactive properties. This study focuses on peptide amphiphdes that form hydrogels and have shown potential anti-microbial and anti-parasitic activities, particularly against drug-resistant strains of Leishmania. The amphiphdes were synthesized and characterized, and their self-assembly, gelation behavior, and properties were investigated. The results demonstrate that these gelators have both antibacterial and antiparasitic activities, making them promising therapeutic agents against leishmaniasis.
Article
Chemistry, Multidisciplinary
Barbara B. Gerbelli, Pedro L. O. Filho, Bruna Cortez, Pedro T. Sodre, Mauricio D. Coutinho-Neto, Ian W. Hamley, Jani Seitsonen, Wendel A. Alves
Summary: The use of lipopeptide sequences as biomimetic microenvironments of acetylcholinesterase (AChE) has shown higher catalytic activities than natural enzymes in water solution, potentially valuable for pesticide detection.
NANOSCALE ADVANCES
(2022)
Review
Nanoscience & Nanotechnology
Ian W. Hamley
Summary: This review discusses the use of peptide epitopes as antigens in vaccine development, focusing on their potential in clinical trials and as future vaccine candidates. It covers peptides used in immunotherapies for infectious diseases and cancer vaccines, as well as their application in stimulating non-specific immune responses and as self-adjuvanting peptides. The review highlights the specificity of the immune response that can be achieved using peptide epitopes and the potential for future therapies.
ACS APPLIED BIO MATERIALS
(2022)
