Block Copolymer Surface Research Articles

Self-Assembled Block Copolymers as a Facile Pathway to Create Functional Nanobiosensor and Nanobiomaterial Surfaces.

Block copolymer (BCP) surfaces permit an exquisite level of nanoscale control in biomolecular assemblies solely based on self-assembly. Owing to this, BCP-based biomolecular assembly represents a much-needed, new paradigm for creating nanobiosensors and nanobiomaterials without the need for costly and time-consuming fabrication steps. Research endeavors in the BCP nanobiotechnology field have led to stimulating results that can promote our current understanding of biomolecular interactions at a solid interface to the never-explored size regimes comparable to individual biomolecules. Encouraging research outcomes have also been reported for the stability and activity of biomolecules bound on BCP thin film surfaces. A wide range of single and multicomponent biomolecules and BCP systems has been assessed to substantiate the potential utility in practical applications as next-generation nanobiosensors, nanobiodevices, and biomaterials. To this end, this Review highlights pioneering research efforts made in the BCP nanobiotechnology area. The discussions will be focused on those works particularly pertaining to nanoscale surface assembly of functional biomolecules, biomolecular interaction properties unique to nanoscale polymer interfaces, functionality of nanoscale surface-bound biomolecules, and specific examples in biosensing. Systems involving the incorporation of biomolecules as one of the blocks in BCPs, i.e., DNA-BCP hybrids, protein-BCP conjugates, and isolated BCP micelles of bioligand carriers used in drug delivery, are outside of the scope of this Review. Looking ahead, there awaits plenty of exciting research opportunities to advance the research field of BCP nanobiotechnology by capitalizing on the fundamental groundwork laid so far for the biomolecular interactions on BCP surfaces. In order to better guide the path forward, key fundamental questions yet to be addressed by the field are identified. In addition, future research directions of BCP nanobiotechnology are contemplated in the concluding section of this Review.

Constructing a Comprehensive Nanopattern Library through Morphological Transitions of Block Copolymer Surface Micelles via Direct Solvent Immersion.

This study establishes a comprehensive library of nanopatterns achievable by a single block copolymer (BCP), ranging from spheres to complex structures like split micelles, flower-like clusters, toroids, disordered micelle arrays, and unspecified unique shapes. The ordinary nanostructures of polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) surface micelles deposited on a SiOx surface undergo a unique morphology transformation when immersed directly in solvents. Investigating parameters such as immersion solvents, BCP molecular weight, substrate interactions, and temperature, this work reveals the influence of these parameters on the thermodynamics and kinetics governing the morphology transformation. Additionally, the practical application of BCP nanopattern templates for fabricating metal nanostructures through direct solvent immersion of surface micelles is demonstrated. This approach offers an efficient and effective method for producing diverse nanostructures, with the potential to be employed in nanolithography, catalysts, electronics, membranes, plasmonics, and photonics.

Hierarchical structure of poly(ε-caprolactone) crystals on its copolymer poly(l-lactide-co-ε-caprolactone) fibers

In crystallization, heterogeneous structures of copolymers are employed to establish a hierarchical architecture comprising two polymers, this typically occurs on the surface of block copolymers or blended polymers. While hierarchical structures in block copolymer fibers are well-established and widely utilized, achieving a regular hierarchical structure on random copolymer fibers is both meaningful and challenging. Here, we present a case of forming a hierarchical structure on the surface of the random copolymer poly(L-lactide-co-caprolactone) (PLCL)fibers. The (ε-caprolactone)(CL) polymer chain segments of the random copolymer are released on the surface of the modified copolymer fiber using sodium hydroxide. Subsequently, poly(ε-caprolactone)(PCL) forms a shish kebab-like crystalline structure under the guidance of the CL segments. The CL segments act as crystalline precursors to induce the formation of heterogeneous PLCL/PCL shish kebab structures. The variation of CL segments on the fiber changes with modification time, leading to the formation of crystalline lamellae of different sizes, which had been confirmed by characterization techniques such as scanning electron microscope (SEM), 1H NMR, X-ray photoelectron spectra (XPS), differential scanning calorimetry (DSC), etc. The implementation of this heterogeneous structure provides possibilities for the implementation of hierarchical structure in random copolymers.

Block Copolymer Approach toward Selective Atomic‐Layer Deposition of ZnO Films

High‐quality thin films of ZnO fabricated with atomic‐layer precision are attracting increasing interest in various applications beyond the conventional semiconductor industry. This has posed new demands for these thin films regarding, for example, the substrate compatibility and substrate‐selective deposition. Herein, the impact of different underlining polymer substrates on the film growth characteristics of ZnO coatings fabricated with the atomic‐layer deposition (ALD) technique is investigated. The resultant thin films are systematically characterized for the growth rate, crystallinity, surface morphology, hydrophilicity, and electrical conductivity. Most excitingly, based on the understanding gained for the ZnO film growth on the different homopolymer surfaces, nanoscale‐patterned block copolymer (BCP) films via spin coating are designed and fabricated to demonstrate block‐selective ALD of ZnO on these BCP surfaces. It will be shown that the polyethylene oxide parts of the BCP act as a significantly more passive surface for the ZnO growth than the polystyrene. Altogether, this concept couples two highly controllable methods—atomic‐level precision of ALD and nanoscale precision of BCP substrates—into a simple and scalable way of producing diverse nanomaterial patterns.

Ferrocene-Based Terpolyamides and Their PDMS-Containing Block Copolymers: Synthesis and Physical Properties

Aromatic polyamides are well-known as high-performance materials due to their outstanding properties making them useful in a wide range of applications. However, their limited solubility in common organic solvents restricts their processability and becomes a hurdle in their applicability. This study is focused on the synthesis of processable ferrocene-based terpolyamides and their polydimethylsiloxane (PDMS)-containing block copolymers, using low-temperature solution polycondensation methodology. All the synthesized materials were structurally characterized using FTIR and 1H NMR spectroscopic techniques. The ferrocene-based terpolymers and block copolymers were soluble in common organic solvents, while the organic analogs were found only soluble in sulfuric acid. WXRD analysis showed the amorphous nature of the materials, while the SEM analysis exposed the modified surface of the ferrocene-based block copolymers. The structure-property relationship of the materials was further elucidated by their water absorption and thermal behavior. These materials showed low to no water absorption along with their high limiting oxygen index (LOI) values depicting their good flame-retardant behavior. DFT studies also supported the role of various monomers in the polycondensation reaction where the electron pair donation from HOMO of diamine monomer to the LUMO of acyl chloride was predicted, along with the calculation of various other parameters of the representative terpolymers and block copolymers.

Block Copolymer Nanopatterning for Nonsemiconductor Device Applications.

Block copolymer (BCP) nanopatterning has emerged as a versatile nanoscale fabrication tool for semiconductor devices and other applications, because of its ability to organize well-defined, periodic nanostructures with a critical dimension of 5-100 nm. While the most promising application field of BCP nanopatterning has been semiconductor devices, the versatility of BCPs has also led to enormous interest from a broad spectrum of other application areas. In particular, the intrinsically low cost and straightforward processing of BCP nanopatterning have been widely recognized for their large-area parallel formation of dense nanoscale features, which clearly contrasts that of sophisticated processing steps of the typical photolithographic process, including EUV lithography. In this Review, we highlight the recent progress in the field of BCP nanopatterning for various nonsemiconductor applications. Notable examples relying on BCP nanopatterning, including nanocatalysts, sensors, optics, energy devices, membranes, surface modifications and other emerging applications, are summarized. We further discuss the current limitations of BCP nanopatterning and suggest future research directions to open up new potential application fields.

Distinctive Adsorption Mechanism and Kinetics of Immunoglobulin G on a Nanoscale Polymer Surface.

Elucidation of protein adsorption beyond simple polymer surfaces to those presenting greater chemical complexity and nanoscopic features is critical to developing well-controlled nanobiomaterials and nanobiosensors. In this study, we repeatedly and faithfully track individual proteins on the same nanodomain areas of a block copolymer (BCP) surface and monitor the adsorption and assembly behavior of a model protein, immunoglobulin G (IgG), over time into a tight surface-packed structure. With discrete protein adsorption events unambiguously visualized at the biomolecular level, the detailed assembly and packing states of IgG on the BCP nanodomain surface are subsequently correlated to various regimes of IgG adsorption kinetic plots. Intriguing features, entirely different from those observed from macroscopic homopolymer templates, are identified from the IgG adsorption isotherms on the nanoscale, chemically varying BCP surface. They include the presence of two Langmuir-like adsorption segments and a nonmonotonic regime in the adsorption plot. Via correlation to time-corresponding topographic data, the unique isotherm features are explained with single biomolecule level details of the IgG adsorption pathway on the BCP. This work not only provides much needed, direct experimental evidence for time-resolved, single protein level, adsorption events on nanoscale polymer surfaces but also signifies mutual linking between specific topographic states of protein adsorption and assembly to particular segments of adsorption isotherms. From the fundamental research viewpoint, the correlative ability to examine the nanoscopic surface organizations of individual proteins and their local as well as global adsorption kinetic profiles will be highly valuable for accurately determining protein assembly mechanisms and interpreting protein adsorption kinetics on nanoscale surfaces. Application-wise, such knowledge will also be important for fundamentally guiding the design and development of biomaterials and biomedical devices that exploit nanoscale polymer architectures.

Selective Deposition of Copper on Self-Assembled Block Copolymer Surfaces via Physical Vapor Deposition.

Block copolymer (BCP) self-assembly produces chemically and topographically patterned surfaces which are used to guide the formation of Cu nanostructures by exploiting differences in the mobility of vapor-deposited species on each microdomain. Cu metal films a few nm thick were deposited on three different BCP surfaces self-assembled from poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP). For PS-b-PMMA, the effects of chemical heterogeneity dominate over the effects of the 2 nm peak-to-valley topography, and sputtered Cu preferentially wets the PS block. PS-b-P2VP has greater chemical and topographical contrast and shows a wider process window for selective deposition. Cu grown by evaporation has less surface mobility, and shadowing effects are believed to dominate pattern formation. The hierarchical self-assembly process of thin metal films on BCP surfaces provides a route to fabricating heterogeneous metallic nanostructures.

Surface Segregation and Self‐Assembly of Block‐Copolymer Separation Layers on Top of Homopolymer Substructures in Asymmetric Ultrafiltration Membranes from a Single Casting Step

AbstractSurface segregation in blended polymer films has attracted much interest in fundamental research as well as for practical applications. A variety of methodologies have been proposed for controlling surface segregation. They often require long annealing times, however, to achieve thermodynamic equilibrium. Here, a strategy and proof‐of‐principle experiments are described to control surface segregation of thin block‐copolymer (BCP) layers on top of a homopolymer in a single casting step from blended BCP/homopolymer solutions. The surface coverage by the minor constituent BCP (2–10 wt%) is accomplished despite almost identical surface energies of BCP and homopolymer constituents. Immersing this casted solution into water for nonsolvent induced phase separation (NIPS), a nonequilibrium process, affords solidified bilayer ultrafiltration membranes composed of a thin porous surface layer of self‐assembled BCP atop an asymmetric porous homopolymer substructure. Key to successful BCP surface segregation is the choice of a binary solvent system based on careful considerations of solvent surface energies and polymer‐solvent interaction parameters. Furthermore, stabilizing the BCP micellar structure by a divalent metal additive is also essential. The approach provides a cost‐effective method for fabricating bilayer‐type asymmetric ultrafiltration membranes with uniform BCP self‐assembly based selective top surface pore layers in a single casting step.

Highly-loaded protein nanocarriers prepared by Flash NanoPrecipitation with hydrophobic ion pairing

The efficient encapsulation of therapeutic proteins into delivery vehicles, particularly without loss of function, remains a significant research hurdle. Typical liposomal formulations achieve drug loadings on the order of 3–5% and encapsulation efficiencies around 50%. We demonstrate the encapsulation of model proteins with isoelectric points above and below pH 7 into nanocarriers (NCs) with protein loadings as high as 46% and encapsulation efficiencies above 95%. This is done by combining the continuous nanofabrication process Flash NanoPrecipitation (FNP) with the technique of hydrophobic ion pairing by forming and encapsulating an ionic complex within a nanocarrier stabilized by a block copolymer surface layer.We complex and encapsulate lysozyme with two anionic hydrophobic counterions, sodium oleate and sodium dodecyl sulfate, using either a pre-formed complex or in situ pairing. The strategy successfully forms NCs ~150 nm in diameter and achieves encapsulation efficiencies over 95%. Protein release rate from the NCs in physiological conditions and the bioactivity of released lysozyme are measured, and both are found to vary with the complexing counterion and the protein/counterion ratio used during formulation. Protein release on the time scale of weeks is observed, and up to 100% bioactivity is measured from released lysozyme.16 quaternary ammonium cationic counterions are tested to encapsulate ovalbumin in 32 formulations. Of these, 19 successfully form ~150 nm NCs with loadings up to 29% and encapsulation efficiencies up to 88%. We divide the formulations into four regimes and identify chemical factors responsible for the success or failure of a given counterion to formulate NCs with the desirable size, loading, and encapsulation efficiency. A successful ovalbumin NC formulation was then tested in vivo in a mouse nasal vaccine model and found to induce a higher titer of OVA-specific IgG than unencapsulated ovalbumin.Taken together, these findings suggest that Flash NanoPrecipitation with hydrophobic ion pairing is an attractive platform for encapsulating high molecular weight proteins into NCs. In particular, the ability to tune protein release rate by varying the counterion or protein/counterion ratio used during formulation is a useful feature.

Research and application of flexible wearable electronics based on nanogenerator in touch sensor

<sec>With the advance of the fourth industrial revolution, a wave of emerging industries and interdisciplinary research is breaking out, such as the Internet of Things, megadata, humanoid robots and artificial intelligence.The rapid development of these functional electronic devices is changing the way people communicate with each other and their surroundings, thus integrating our world into an intelligent information network. The applications of flexible wearable electronic devices in intelligent robots, health and medical monitoring and other fields have attracted great attention. Following the human skin, the device can respond to external stimuli and should also have stretchability and self-healing properties. In practical applications, a large network of sensors is needed to connect with humans or robots, so the supply of energy is crucial. Several forms of green and renewable energy have been searched for, such as magnetic energy, solar energy, thermal energy, mechanical energy and microbial chemical energy. However, high cost, limitations in the choice of materials, and other disadvantages have become serious bottlenecks.</sec><sec>The advent of nanogenerator brings a novel and effective solution to the above problems. Here in this work, the triboelectronic nanogenerator (TENG) and the piezoelectric generator (PENG) are taken as two representative objectives, which are, respectively, based on the triboelectronic effect and piezoelectronic effect to realize the collection of mechanical energy, and each of them can be used as a self-power sensor, which can generate electrical signals, respond to environmental stimuli, and need no power supply any more.</sec><sec>The optimization and design of nanogenerator is always a key factor to improve its performance and wide application. At present, the methods commonly adopted in optimization schemes mainly include material selection, design and optimization of structural layer and electrode. The selection of materials should be based on low cost, stretchability, transparency, stability and biocompatibility. Firstly, for the optimization of structural layer, there are mainly two ways of designing the materials, one is the microstructure of the material surface, and the other is the functionalization of materials.The performance of the nanogenerator is proportional to the charge density of the contact surface. The square of the charge density is the main parameter to quantify the performance of the nanogenerator. Therefore, increasing the charge generation has been the main strategy to improve the output power. The microstructure of materials can be realized by means of colloidal arrays, soft lithography, block copolymer components and surface nanomaterial manufacturing. The same materials can be functionalized by ion doping, plasma treatment, electrical polarization, laser induction, and the formation of nanocomposites. In practical application, more attention is paid to the electrode with excellent performance which can simplify device structure, improve device performance and expand application field. The design of the electrode more focuses on the features such as flexibility, stretchability, high transparency and excellent electrical conductivity. The touch sensors based on TENG and PENG such as pressure sensors, strain sensors, pressure distribution sensors and slip sensors have shown excellent performances in application. Self-powered pressure sensors are used most widely because they are highly sensitive to and can detect the subtle pressure changes such as respiratory or arterial pulse-related changes. Strain sensors can detect signals produced by the body during mechanical movements, such as walking and joint movements. Pressure distribution sensor and slip distribution sensor play a key role in touch screen and smart prosthesis and so on.</sec><sec>In this article, first, we introduce the mechanism of TENG and PENG, and summarize the way of performing the optimization design of the nanogenerators. Then, we discuss the self-powered sensors based on the nanogenerators such as stress, strain and distribution and slip sensors by combining the marerials and the design of device. Finally, the problems and challenges of the tactile sensor based on the nanogenerators are discussed, and the future development is prospected.</sec>

Low-Temperature Plasma Modification of Styrene-Butadiene Block Copolymer Surfaces for Improved Adhesion-A Kinetic Approach.

This paper proposed a kinetic model that can describe the changes in the adhesion properties of styrene–butadiene (SBS) block copolymer surfaces under the influence of low-temperature plasma treatment. As a measure of these changes, the peel strength of joints formed between the copolymer surface and the polyurethane adhesive was chosen. Five types of low-temperature low-pressure RF plasma, two inert plasmas (Ar and He), and three reactive plasmas (O2, CO2, and CCl4) were tested. It was found that for all these types of plasma, the peel strength with the plasma treatment time first increases rapidly reaching a maximum value, and then there is a visible decrease in peel strength, after which the peel strength increases again. This dependence of the peel strength on the plasma treatment time is very well described by the proposed model, which considers three processes: (1) the generation of radical states followed by the creation of functional groups involved in the adhesive bonding process, (2) the surface cross-linking that decreases the concentration of these functional groups, and (3) the formation of nano-roughness. The model analysis revealed differences between the action of reactive and inert plasmas in the SBS surface cross-linking mechanism and preferential etching process, as well as differences in the generation of radical states between the O2 plasma (electron process) and other plasmas tested (ionic processes).

Formation of the Wrinkle Structure on a Styrene–Butadiene–Styrene Block Copolymer Surface by Surface Chemical Reformation via Ion-Beam Irradiation

A styrene-butadiene-styrene (SBS) block copolymer was utilized to fabricate the wrinkle pattern in accordance with the buckling theory, and ion-beam (IB) irradiation was applied to induce surface r...

Five Piconewtons: The Difference between Osteogenic and Adipogenic Fate Choice in Human Mesenchymal Stem Cells.

The ability of mesenchymal stem cells to sense nanoscale variations in extracellular matrix (ECM) compositions in their local microenvironment is crucial to their survival and their fate; however, the underlying molecular mechanisms defining how such fates are temporally modulated remain poorly understood. In this work, we have utilized self-assembled block copolymer surfaces to present nanodomains of an adhesive peptide found in many ECM proteins at different lateral spacings (from 30 to 60 nm) and studied the temporal response (2 h to 14 days) of human mesenchymal stem cells (hMSCs) using a panel of real-time localization and activity biosensors. Our findings revealed that within the first 4 to 24 h postadhesion and spreading, hMSCs on smaller nanodomain spacings recruit more activated FAK and Src proteins to produce larger, longer-lived, and increased numbers of focal adhesions (FAs). The adhesions formed on smaller nanospacings rapidly recruit higher amounts of nonmuscle myosin IIA and vinculin and experience tension forces (by >5 pN/FA) significantly higher than those observed on larger nanodomain spacings. The transmission of higher levels of tension into the cytoskeleton at short times was accompanied by higher Rac1, cytosolic β-catenin, and nuclear localization of YAP/TAZ and RUNX2, which together biased the commitment of hMSCs to an osteogenic fate. This investigation provides mechanistic insights to confirm that smaller lateral spacings of adhesive nanodomains alter hMSC mechanosensing and biases mechanotransduction at short times via differential coupling of FAK/Src/Rac1/myosin IIA/YAP/TAZ signaling pathways to support longer-term changes in stem cell differentiation and state.

Revealing the principal attributes of protein adsorption on block copolymer surfaces with direct experimental evidence at the single protein level

Understanding protein adsorption onto polymer surfaces is of great importance in designing biomaterials, improving bioanalytical devices, and controlling biofouling, to name a few examples. Although steady research efforts have been advancing this field, our knowledge of this ubiquitous and complex phenomenon is still limited. In this study, we elucidate competitive protein adsorption behaviors sequentially occurring onto nanoscale block copolymer (BCP) surfaces via combined experimental and computer simulation approaches. The model systems chosen for our investigation are immunoglobulin G and fibrinogen introduced in different orders into the self-assembled nanodomains of poly(styrene)-block-poly(methylmethacrylate). We unambiguously reveal the adsorption, desorption, and replacement events of the same protein molecules via single protein tracking with atomic force microscopy. We then ascertain adsorption-related behaviors such as lateral mobility and self-association of proteins. We provide the much-needed, direct experimental proof of sequential adsorption events at the biomolecular level, which was virtually nonexistent before. We determine key protein adsorption pathways and dominant tendencies of sequential protein adsorption. We also reveal preadsorbed surface-associated behaviors in sequential adsorption, distinct from situations involving initially empty surfaces. We perform Monte-Carlo simulations to further substantiate our experimental outcomes. Our endeavors in this study may facilitate a well-guided mechanistic understanding of protein-polymer interactions by providing definite experimental evidence of competitive, sequential adsorption at the nanoscale. Increasingly, biomaterial and biomedical applications rely on systems of multicomponent proteins and chemically intricate, nanoscale polymer surfaces. Hence, our findings can also be beneficial for the development of next-generation nanobiomaterials and nanobiosensors exploiting self-assembled BCP nanodomain surfaces.

Effect of Polycaprolactone Crystalline Block on Surface Reorganization of a Phosphorylcholine-based Amphiphilic Block Copolymer Surface Modifier

The surface reorganization behavior of a crystalline ABCBA-type copolymer and a non-crystalline ABA-type copolymer including poly(2-methacryloyloxyethyl phosphorylcholine) was investigated. The crystalline domain in the block copolymer suppressed the surface reorganization when exposed to either hydrophilic or hydrophobic condition.

Controllable Location of Inorganic Nanoparticles on Block Copolymer Self-Assembled Scaffolds by Tailoring the Entropy and Enthalpy Contributions

Precisely controlling the spatial location and alignment of functional nanoparticles (NPs) on polymeric scaffolds is of great importance to not only create novel nanostructures but also enhance the properties of the hybrid nanomaterials. Herein, we demonstrate a strategy of tailoring the entropic and enthalpic contributions to precisely position gold nanoparticles (AuNPs) on block copolymer (BCP) scaffolds through the confined coassembly of BCPs and AuNPs within the emulsion droplet. According to this strategy, entropic effect arisen by the loss in conformational entropy and the enthalpic attraction between ligands on AuNPs and surfactants at the oil/water interface induce the solid AuNPs to move to the BCP surface, while the enthalpic interaction between the ligands on AuNPs and the corresponding polymer chains guides the AuNPs to position at the appropriate place. By this strategy, both the location and alignment of AuNPs on BCP scaffolds can be controlled at will, such as at the two terminals or along ...

Multi-MHz micro-electro-mechanical sensors for atomic force microscopy

Silicon ring-shaped micro-electro-mechanical resonators have been fabricated and used as probes for dynamic atomic force microscopy (AFM) experiments. They offer resonance frequency above 10MHz, which is notably greater than that of usual cantilevers and quartz-based AFM probes. On-chip electrical actuation and readout of the tip oscillation are obtained by means of built-in capacitive transducers. Displacement and force resolutions have been determined from noise analysis at 1.5fm/√Hz and 0.4 pN/√Hz, respectively. Despite the high effective stiffness of the probes, the tip-surface interaction force is kept below 1 nN by using vibration amplitude significantly below 100pm and setpoint close to the free vibration conditions. Imaging capabilities in amplitude- and frequency-modulation AFM modes have been demonstrated on block copolymer surfaces. Z-spectroscopy experiments revealed that the tip is vibrating in permanent contact with the viscoelastic material, with a pinned contact line. Results are compared to those obtained with commercial AFM cantilevers driven at large amplitudes (>10nm).

Structural Requirements of Block Copolymers for Self-Assembly into Inverse Bicontinuous Cubic Mesophases in Solution

Inverse bicontinuous cubic (IBC) structures consisting of triply periodic minimal surfaces of block copolymers (BCPs) are emerging as materials of interest owing to their structural characteristics, which resemble those of their biological counterparts constructed from lipids. Solution self-assembly of amphiphilic BCPs with nonlinear architectures has recently been shown to form colloidal particles (polymer cubosomes) and macroscopic monoliths having mesoporous networks of water channels embedded in the periodic minimal surfaces of the BCP bilayers. Here we report that BCP architectures play a crucial role in controlling the packing parameter (P) of BCPs; a value greater than unity is a prerequisite for preferential self-assembly into IBC mesophases in solution. We show that the branched architecture of the polymer blocks constituting the BCP critically influences the structural parameters, such as the molecular area and, in particular, the critical length of the hydrophobic domain. Adjusting these struct...

Anti-Biofouling Effect of PEG-Grafted Block Copolymer Synthesized by RAFT Polymerization.

Poly(glycidyl methadrylate-block-styrene) (PGMA-b-PS), a block copolymer consisting of glycidyl methacrylate and styrene, was synthesized via reversible addition-fragmentation chain transfer living polymerization. The synthesized PGMA-b-PS was then grafted with low-molecular-weight polyethylene glycol (PEG) via epoxy ring opening to give PGMA-g-PEG-b-PS, which was evaluated as an anti-biofouling coating material. As a preliminary test for the anti-biofouling effect, a protein adsorption experiment was performed on the synthesized block copolymer surface. The block copolymers were spin-coated onto silicon wafers, and protein adsorption experiments were carried out using fluorescein isothiocyanate conjugate-labeled bovine serum albumin. The fluorescence intensity of the protein adsorbed on the block copolymer surface was compared with that of a polystyrene film as a reference. The synthesized PGMA-g-PEG-b-PS film showed much lower fluorescence intensity than that of the PS film.