Microphase-separated Domains Research Articles

Statistical properties of microphase and bubbly phase-separated active fluids.

In phase-separated active fluids, the Ostwald process can go into reverse, leading to either microphase separation or bubbly phase separation. We show that the latter is formed of two macroscopic regions that are occupied by the homogeneous fluid and by the microphase separated one. Within the microphase-separated fluid, the relative rate of the Ostwald process, coalescence, and nucleation determines whether the size distribution of mesoscopic domains is narrowly peaked or displays a broad range of sizes before attaining a cutoff independent of system size. Our results are obtained via large-scale simulations of a minimal field theory for active phase separation and reproduced by an effective model in which the degrees of freedom are the locations and sizes of the microphase-separated domains.

Segregation kinetics of miktoarm star polymers: A dissipative particle dynamics study.

We study the phase separation kinetics of miktoarm star polymer (MSP) melts/blends with diverse architectures using dissipative particle dynamics simulation. Our study focuses on symmetric and asymmetric miktoarm star polymer (SMSP/AMSP) mixtures based on arm composition and number. For a fixed MSP chain size, the characteristic microphase-separated domains initially show diffusive growth with a growth exponent ϕ∼1/3 for both melts that gradually crossover to saturation at late times. The simulation results demonstrate that the evolution morphology of SMSP melt exhibits perfect dynamic scaling with varying arm numbers; the timescale follows a power-law decay with an exponent θ≃1 as the number of arms increases. The structural constraints on AMSP melts cause the domain growth rate to decrease as the number of one type of arms increases while their length remains fixed. This increase in the number of arms for AMSP corresponds to increased off-criticality. The saturation length in AMSP follows a power-law increase with an exponent λ≃2/3 as off-criticality decreases. Additionally, macrophase separation kinetics in SMSP/AMSP blends show a transition from viscous (ϕ∼1) to inertial (ϕ∼2/3) hydrodynamic growth regimes at late times; this exhibits the same dynamical universality class as linear polymer blends, with slight deviations at early stages.

Reaction-induced morphological transitions in a blend of diblock copolymers and reactive monomers: dissipative particle dynamics simulation.

The dissipative particle dynamics (DPD) method is applied to the morphological transitions of microphase-separated domains in a mixture of symmetric AB-diblock copolymers and reactive C-monomers, where polymerization and cross-linking reactions take place among C-monomers. The initial structure for the DPD simulation is an equilibrated cylindrical domain structure prepared by the density-biased Monte Carlo method with density profiles obtained from the self-consistent field theory. By introducing a cross-linking reaction among reactive C-monomers, we confirmed that the DPD simulation reproduces the morphological transitions observed in experiments, where the domain morphology changes due to segregation between A-blocks of diblock copolymers and cross-linking networks of C-monomers. When the cross-linking reaction of C-monomers is sufficiently fast compared to the deformation of the domains, the initial cylindrical domains are preserved, while the distance between the domains increases. On the other hand, when the formation of the cross-linking network is slow, the domains can deform and reconnect with each other in the developing cross-linking network. In this case, we observe morphological transitions from the initial domain morphology with a large-curvature interface to another domain morphology with a smaller-curvature interface, such as the transition from the cylindrical phase to the lamellar phase. We calculated the spatial correlations in the microphase-separated domains and found that such correlations are affected by the speed of the formation of the cross-linking network depending on whether the bridging between microphase-separated domains occurs in a nucleation and growth process or in a spinodal decomposition process.

The effect of high-temperature proton exchange membranes with microphase separation structure on phosphoric acid loss

Phosphoric acid (PA) leakage of PA-doped high-temperature proton exchange membranes (HT-PEMs) is pivotal for its practical application under working conditions. Here, to enhance the PA retention of HT-PEMs, the concept of microphase separation regulated by flexible long aliphatic side-chain was introduced into poly(isatin-co-p-terphenyl-imidazole) matrix (PITI-CmQ90) via direct superacid-catalyzed copolymerization from N-alkylated isatin monomer. The designed PITI-CmQ90 membranes illustrate obvious microphase separation and larger ionic domain confirmed via Small-angle X-ray scattering (SAXS) analysis suggesting wider proton transport channels. Notably, PA/PITI-C6Q90 membrane exhibits the best PA retention ability under relative humidity (RH) cycle tests at different temperatures, which mainly attributed to the excellent PA interaction through moderate ion aggregation in the microphase-separated PEM matrix verified by solid 31P NMR. As a result, the corresponding MEA displays the most durable single-cell performance under a step-V procedure from 1.0 V to 0.1 V cycle experiments at different temperatures. Therefore, the idea of microphase separation structure on PA retention mentioned in this work helps to study the ionic-pairs interactions from the perspective of membrane microstructure and provide a new strategy to enhance the durability of PEMs.

Constraining effects on polymer chain relaxation in crosslinked supramolecular dual networks

Polymer networks containing transient physical and permanent chemical cross-links exhibit unique mechanical properties due to the intrinsic reassociating ability of supramolecular functional groups. Similar to supramolecular gels, these networks allow the controlled release of stored energy and can extend the life of polymer networks in practical applications. In this study, we investigated the rheology, dielectric spectroscopy, stress–strain behavior, and dynamic mechanical analysis of networks based on long polybutylene oxide (PBO) chains functionalized with randomly placed thymine (Thy) side groups. A transient network was formed by proportionally mixing this matrix with short non-entangled linear 1,3,5-diaminotriazine (DAT) head–tail modified PBO chains, exploiting the hetero-complementarity of the DAT–Thy triple hydrogen bond. This transient polymer network was further cross-linked to a dual network via a thiol-ene click reaction to form static covalent bonds. In PBO, the similar polarity of the PBO matrix and the DAT–Thy functional groups ensures that the molecular chain motion is not affected by segregation, resulting in a homogeneous polymer phase without microphase-separated functional group domains. Dielectric relaxation spectroscopy was combined with rheology to quantify the relaxation processes of the interconnected polymers and the strength of the DAT–Thy bonding interactions in the melt. The results showed two distinct plateaux in the relaxation modulus due to contributions from hydrogen and permanent bonds. In the case of the dual network, the lifetime of the hydrogen bond was prolonged and higher activation energy was observed due to the physical cross-link preventing the movement of the long chain.

Effect of branched structure on microphase separation and electric field induced bending actuation behaviors of poly(urethane–urea) elastomers

Polyurethane elastomers as a type of electroactive polymers have wide applications in soft actuators, soft sensors and energy harvesting due to their high dielectric constant, high electrostriction coefficients, easy processing and structure adjustability, and superior biocompatibility etc. However, the relationship between microstructure and electromechanical properties of EAEs has not been fully understood. In this work, we fabricated the branch structured poly(urethane–urea) elastomers (PUUs) using hydroxy-terminated polybutadiene as soft segment, isophorone diisocyanate and 4,4-diaminodicyclohexylmethane as hard segment, and hydroxyl-terminated four-armed polycaprolactone (PCL410) as branch structured chain extender for improving bending actuation performances, and understanding the relationship between structure and electromechanical properties. The degree of branched structure of PUUs were adjusted by the content of PCL410. The microphase separation kinetics of PUUs was enhanced as increase of PCL410 content, whereas the degree of microphase separation and hard domain size of PUUs were reduced. The mechanical loss and bending actuation stress of PUUs were significantly improved by incorporation of small amount of branched structure into PUU chains. The PUU with 2.60 mol.% of PCL410 showed 5.16 mm of bending displacement and 5.16 Pa of bending actuation stress at 7.2 kV (corresponding to 180 V mm−1 of the nominal electric field), which were 76.3, and 79 times higher than that of PUU without PCL410, respectively. The electric field induced bending actuation mechanism of branch structured PUUs was suggested that the bending actuation mechanism of branch structured PUUs is caused by electrostrictive effect from dipole orientation induced bending deformation of constrained segments and asymmetric charge density distribution on both anode and cathode sides of PUU films. Our results can provide new insight on design novel electroactive polyurethane elastomers.

Orientation control of the hexagonal and lamellar phases in thin block copolymer films using in-plane AC electric field

Lamellar and hexagonal pattern rearrangements in thin films of polystyrene–block–poly(2-vinyl pyridine) and polystyrene–block–poly(4-vinyl pyridine) copolymers simultaneously exposed to an in-plane AC electric field and saturated chloroform vapor are studied with atomic force microscopy and analyzed via the numerical solution of the self-consistent field theory equations. It is demonstrated that the use of AC field with the root-mean-square strength higher than 8 V⋅μm−1 allows one to effectively orient microphase-separated domains along the field direction on the tens of microns scale. At the same time, the AC field considerably lowers the risk of breakdown and eliminates effects related to ionic transport in the presence of solvent vapor. The role of such factors as the exposure time, field strength and frequency is investigated. Theoretical considerations prove the equivalent effect of AC and DC fields on the structure of the copolymer film in a wide frequency range. Self-consistent field theory calculations of the free energy as a function of film thickness make it possible to exactly identify which phase dominates in the film. In particular, an apparent transformation of standing cylinders into long threads aligned in the field direction should be interpreted as the phase transition from the perpendicular to parallel hexagonal phase, which can take place in a certain range of film thicknesses, provided the electric field strength exceeds a certain threshold value. In the case of a perpendicular lamellar phase, the domain orientation along the direction of the electric field is always profitable. The observed morphological rearrangements under an in-plane field, which preserve connectivity between the film surfaces through the domains of the minor copolymer block, can be important for practical applications.

Exploiting the lower disorder-to-order temperature in polystyrene-b-poly(n-butyl acrylate)-b-polystyrene triblock copolymers to increase their flow resistance at high temperature

This work focuses on the temperature-dependent structural and rheological characterization of polystyrene-b-poly(n-butyl acrylate)-b-polystyrene triblock copolymers (PS-b-PnBA-b-PS) in the melt and, in particular, on their ability to show a lower disorder-to-order temperature (LDOT). To this aim, copolymers of varying block lengths, but keeping the PnBA block as a major component, were synthesized. Small-angle x-ray scattering revealed that the copolymers with short PS blocks (∼10 kg/mol) approach an LDOT but do not cross it. At room temperature, these copolymers exhibit higher moduli compared to a PnBA homopolymer due to the reinforcing effect of the PS but are flowing at temperatures above the glass transition of the PS. Increasing the PS and PnBA block length, to keep the same PS fraction, induces more profound changes in the structural and viscoelastic behaviors. Such a copolymer crosses the LDOT, leading to a microphase-separated and ordered state at high temperature. Contrary to the copolymers with short PS blocks, the flow regime was not reached, even at temperatures well above the glass transition of the PS. Instead, a low-frequency plateau was observed in rheology, showing the increased lifetime of the microphase-separated PS domains. ABA triblock copolymers exhibiting an LDOT behavior could, thus, be of interest for the design of thermoplastic elastomers or pressure-sensitive adhesives that can resist the flow at high temperatures.

High strength and toughness transparent waterborne polyurethane with antibacterial performance

To reach a more sustainable society, it is an irresistible trend to replace the solvent-based polyurethane with waterborne polyurethane (WPU). However, it remains a challenge to fabricate WPU materials with excellent mechanical properties. Herein, a transparent WPU with strength of 30.1 MPa and toughness of 195.7 MJ/m3 is developed by incorporating hydantoin diol (HD) into WPU macromolecule. The polar segments of WPU interact with each other by H-bonds and agglomerate together to form hard phase, which disperse in soft polycaprolactone diol (PCL) phase, forming micro-phase separated domains. It significantly enhances the tensile strength and toughness of the WPU. In comparison with covalent bonds, the reversibility of dynamic physical interactions of H-bonds enables the materials to be healed by heating. In addition, the 3 h-healed HDPU2 film exhibits high toughness (166.9 MJ/m3), tensile strength (20.6 MPa) and strain (2195 %). Furthermore, the HDPU2 film presents outstanding antibacterial properties after chlorination, inactivating 100 % of S. aureus and 96.2 % of E. coli within 60 min.

Breaking Mirror Symmetry of Double Gyroids via Self-Assembly of Chiral Block Copolymers.

Significant enhancement of segment-scale chirality, as measured by vibrational circular dichroism (VCD), is observed in the helical phase (H*) of polylactide-based chiral block copolymers (BCPs*) due to the mesoscale chirality of the microphase-separated domains. Here, we report a weaker, yet meaningful, enhancement on the VCD signal of a double gyroid phase (DG) as compared to a double diamond phase (DD) and disordered phase from the same diblock BCPs*. Residual VCD enhancement indicates a weak degree of chiral symmetry breaking, implying the formation of a chiral double gyroid (DG*) instead of the canonical achiral form. Calculations on the basis of orientational self-consistent field theory, comparing coupling between the segmental-scale preference of an intradomain twist and morphological chirality, show that a transition between DG and DG* takes place above the critical chiral strength, driving a weak volume asymmetry between the two enantiomeric single networks of DG*. The formation of nanostructures with controllable mesoscale chiral asymmetry indicates a pathway for the amplification of optical activity driven by self-assembly.

Dual Block Copolymer Morphologies in Ultrathin Films on Topographic Substrates: The Effect of Film Curvature.

The ability to create mixed morphologies using easily controlled parameters is crucial for the integration of block copolymers in advanced technologies. We have previously shown that casting an ultrathin block copolymer film on a topographically patterned substrate results in different deposited thicknesses on the plateaus and in the trenches, which leads to the co-existence of two patterns. In this work, we highlight the dependence of the dual patterns on the film profile. We suggest that the steepness of the film profile formed across the plateau edge affects the nucleation of microphase-separated domains near the plateau edges, which influences the morphology that develops on the plateau regions. An analysis of the local film thicknesses in multiple samples exhibiting various combinations of plateau and trench widths for different trench depths enabled the construction of phase diagrams, which unraveled the intricate dependence of the formed patterns not only on the curvature of the film profile but also on the fraction of the film that resides in the trenches. Our analysis facilitates the prediction of the patterns that would develop in the trenches and on the plateaus for a given block copolymer film of known thickness from the dimensions of the topographic features.

Curving and Twisting in Self-Assembly of Triblock Terpolymers Driven by a Chiral End Block

A series of triblock terpolymers composed of a chiral end block, poly(l-lactide) (PLLA) (designated as chiral triblock terpolymers), are designed and synthesized for self-assembly. The chiral PLLA block can contribute the chirality effect for the twisting of microphase-separated domains. By attaching an asymmetric amount of the chiral block to a symmetric diblock of polyisoprene-b-polystyrene (PI-PS), compositional asymmetry can be created for the curving of microphase-separated domains. Moreover, the difference in persistence lengths of PS and PLLA blocks can give conformational asymmetry to the curving. With the combined effects of twisting and curving, the curvature at the saddle surface of microphase-separated domains might become significant to give the formation of a network phase. Consequently, a transformation from two-domain lamellae to core–shell network phases, then to a core–shell cylinder phase, and finally to a three-domain lamellar phase with undulation due to the rod–rod interaction with the chirality effect from the semiflexible PLLA, can be found in the isopleths of the triblocks. Interestingly, a core–shell double diamond phase could be found near the center of the ternary phase diagram; we speculate that the alleviation of packing frustration in the core of the self-assembled microdomain is attributed to the character of semiflexible PLLA. Accordingly, the phase window of network formation can be enlarged by the combined effects of compositional asymmetry, conformational asymmetry, and chirality.

Nanostructured Block Polymer Electrolytes: Tailoring Self-Assembly to Unlock the Potential in Lithium-Ion Batteries.

ConspectusIon-containing solid block polymer (BP) electrolytes can self-assemble into microphase-separated domains to facilitate the independent optimization of ion conduction and mechanical stability; this assembly behavior has the potential to improve the functionality and safety of lithium-ion batteries over liquid electrolytes to meet future demands (e.g., large capacities and long lifetimes) in various applications. However, significant enhancements in the ionic conductivity and processability of BPs must be realized for BP-based electrolytes to become robust alternatives in commercial devices. Toward this end, the controlled modification of BP electrolytes' intra-domain (nanometer-scale) and multi-grain (micrometer-scale) structure is one viable approach; intra-domain ion transport and segmental compatibility (related to the effective Flory-Huggins parameter, χeff) can be increased by tuning the ion and monomer-segment distributions, and the morphology can be selected such that the multi-grain transport is less sensitive to grain size and orientation.To highlight the characteristics of intra-domain structure that promote efficient ion transport, this Account begins by describing the relationship between BP thermodynamics (namely, χeff and the statistical segment length, b, which is indicative of chain stiffness) and local ion concentration. These thermodynamic insights are vital because they inform the selection of synthesis and formulation variables, such as polymer and ion chemistry, polymer molecular weight and composition, and ion concentration, which boost electrolyte performance. In addition to its relationship with local ion transport, χeff is also an important factor with respect to electrolyte processability. For example, a reduced χeff can allow BP electrolytes to be processed at lower temperatures (i.e., lower energy input), with less solvent (i.e., reduced waste), and/or for shorter times (i.e., higher throughput) yet still form desired nanostructures. This Account also examines the impact of electrolyte preparation and processing on the ion transport across nanostructured grains because of grain size and orientation. As morphologies with a 3D-connected versus 2D-connected conducting phase show different sensitivities to conductivity losses that can occur because of the fabrication methods, it is necessary to account for electrolyte processing effects when probing ion transport.The intra-domain and micrometer-scale structure also can be tuned using either tapered BPs (macromolecules with modified monomer-segment composition profiles between two homogeneous blocks) or blends of BPs and homopolymers, independent of the BP molecular weight and composition, as detailed herein. The application of TBPs or BP/HP blends as ion-conducting materials leads to improved ion transport, reduced χeff, and greater availability of morphologies with 3D connectivity relative to traditional (non-tapered and unblended) BP electrolytes. This feature results from the fact that ion transport is related more closely to the monomer-segment distributions within a domain than the overall nanoscale morphology or average polymer/ion mobilities. Taken together, this Account describes how ion transport and processability are influenced by BP architecture and nanostructural features, and it provides avenues to tune nanoassemblies that can contribute to improved lithium-ion battery technologies to meet future demands.

One-Pot Synthesis of Supertough, Sustainable Polyester Thermoplastic Elastomers Using Block-Like, Gradient Copolymer as Soft Midblock

It remains challenging to synthesize supertough thermoplastic elastomers (TPEs) since the stretchability and tensile strength are mutually exclusive. Here, we report a one-pot strategy for the prep...

Peptide-Controlled Assembly of Anion Exchange Ionomer Thin Films on Electrode Surfaces for Promoting Microphase Separation and Ionic Conductivity

In electrochemical devices such as water electrolyzers and fuel cells, the network and morphology of the conductive ionomers within electrodes are critical for ion delivery and mass transport, significantly influencing the device performance. Most studies investigate these materials as bulk polymer electrolyte membranes and comparatively little attention has been given to their behavior on electrode surfaces as thin films. Anion exchange membrane fuel cells and water electrolyzers (AEMFCs and AEMWEs) would allow the use of non-precious group metals and enable low-cost systems, yet, even less is known about thin films of anion exchange ionomer (AEI). Protein engineering is emerging as a powerful nanomanufacturing tool to control the organization of components on electrodes. In this work, we propose that it can be applied to ionomer control, demonstrating that sequence defined elastin-like peptides assembled on electrode surfaces, and/or solvent vapor annealing processing, alters the microstructure configuration of assembled thin films of anion exchange ionomer. It is observed that peptides form a uniform monolayer on the metal surface, and moderately sized microphase separated ionic domains of the AEI are obtained either by modifying the electrode with peptides or solvent vapor annealing, which correlate with an increased in-plane ionic conductivity of the thin film. Interestingly, the use of peptide-modified electrodes in conjunction with solvent vapor annealing yields excessively large ionic grains that correlates with compromised ionic conductivity. Overall, we show that sequence defined peptides could serve as a tool for controlling electrode architecture, and judicious use of peptides, or solvent vapor annealing, have the potential to control the microstructure of thin AEI films and lead to structure-function understanding.

Characterisation of the PS-PMMA Interfaces in Microphase Separated Block Copolymer Thin Films by Analytical (S)TEM.

Block copolymer (BCP) self-assembly is a promising tool for next generation lithography as microphase separated polymer domains in thin films can act as templates for surface nanopatterning with sub-20 nm features. The replicated patterns can, however, only be as precise as their templates. Thus, the investigation of the morphology of polymer domains is of great importance. Commonly used analytical techniques (neutron scattering, scanning force microscopy) either lack spatial information or nanoscale resolution. Using advanced analytical (scanning) transmission electron microscopy ((S)TEM), we provide real space information on polymer domain morphology and interfaces between polystyrene (PS) and polymethylmethacrylate (PMMA) in cylinder- and lamellae-forming BCPs at highest resolution. This allows us to correlate the internal structure of polymer domains with line edge roughnesses, interface widths and domain sizes. STEM is employed for high-resolution imaging, electron energy loss spectroscopy and energy filtered TEM (EFTEM) spectroscopic imaging for material identification and EFTEM thickness mapping for visualisation of material densities at defects. The volume fraction of non-phase separated polymer species can be analysed by EFTEM. These methods give new insights into the morphology of polymer domains the exact knowledge of which will allow to improve pattern quality for nanolithography.

Nonequilibrium Theory of Epigenomic Microphase Separation in the Cell Nucleus.

Understanding the spatial organization of the genome in the cell nucleus is one of the current grand challenges in biophysics. Certain biochemical-or epigenetic-marks that are deposited along the genome are thought to play an important, yet poorly understood, role in determining genome organization and cell identity. The physical principles underlying the interplay between epigenetic dynamics and genome folding remain elusive. Here we propose and study a theory that assumes a coupling between epigenetic mark and genome densities, and which can be applied at the scale of the whole nucleus. We show that equilibrium models are not compatible with experiments and a qualitative agreement is recovered by accounting for nonequilibrium processes that can stabilize microphase separated epigenomic domains. We finally discuss the potential biophysical origin of these terms.

Role of Solvation on Diffusion of Ions in Diblock Copolymers: Understanding the Molecular Weight Effect through Modeling.

Salt-doped diblock copolymers with microphase-separated domains of both an ion conductive and a mechanically strong polymer have been extensively studied due to their potential in transport applications. Several unusual or counterintuitive trends regarding their transport properties have been observed experimentally, such as increasing ion conduction as a function of molecular weight. A crucial feature of these systems is the strong solvation of ions in the conducting microphase due to its higher dielectric constant. Here, we perform molecular dynamics simulations using a coarse-grained model that includes a 1/r4 potential form to generically represent ion solvation, allowing us to reproduce experimentally observed trends and explore their molecular underpinnings. We find that increasing ion concentration can increase or decrease ion diffusion, depending on solvation strength. We also show that the trend of increasing diffusion with molecular weight becomes more dramatic as ions are solvated in one polymer block more strongly or as the ion-ion interactions get stronger. In contrast to expectations, the interfacial width or the overlap of ions with the nonconductive polymer block does not adequately explain this phenomenon; instead, local ion agglomeration best explains reduced diffusion. Interfacial sharpening, controlled by the Flory χ parameter and molecular weight, tends to allow ions to spread more uniformly, and this increases their diffusion.

Rheological investigation of carbon-based hybrid polyurethane nanocomposites with continuous networks

Carbon-based fillers were used as reinforcement for thermoplastic polyurethane (TPU) matrix. For the first time the rheological behavior of hybrid polyurethane nanocomposite has been surveyed and the formation of continuous network of two carbon-based fillers has been reported. Nanocomposites containing multi-walled carbon nanotubes (MWCNTs), carbon fibers (CFs) and MWCNTs/CFs were prepared through melt compounding method and evaluated with various techniques including microscopy, spectroscopy and comprehensive rheological analyses. Linear rheological methods such as strain, frequency, temperature and time sweeps, and non-linear flow curve method were adopted to study the viscoelastic properties of the nanocomposites. Attenuated total reflectance Fourier transform infrared spectroscopy showed that MWCNTs had higher interactions with TPU hard segments due to their high aspect ratio, whereas CFs had low interactions. In hybrid nanocomposite, a continuous network of carbon-based fillers was created which acted as a surface for nucleation of hard segment and induced the highest influence on viscoelastic behavior of resulting nanocomposites. Based on the microscopy analyses, existence of co-continuous morphology was observed for hybrid nanocomposite. Moreover, relationship between the structure of nanofillers and formation of microphase separated domains at various nanofiller contents was discussed. At first, the rheological behavior of each nanocomposite was separately studied. To conclude, the results corroborated that CFs and MWCNTs formed a network of carbon-based structure and changed the viscoelastic properties of hybrid nanocomposites.

Supramolecular luminescent triblock copolymer thermoplastic elastomer via metal-ligand coordination

Abstract We have performed synthesis and testing of novel supramolecular thermoplastic elastomers (TPEs). The polymers incorporate metal-ligand bonds between terbium (Tb3+) ions and imidazole groups in a triblock copolymer poly(isobornyl acrylate)-block-poly(n-butyl acrylate-co-1-vinylimidazole)-block-poly(isobornyl acrylate) (PIBA-b-P(BA-co-VI)-b-PIBA) as a second reversible physical cross-link in addition to the effective physical cross-linking from the microphase separated domains. The resulting supramolecular TPEs are optically active with efficient photoluminescence and mechanically tough with both high tensile strength and high stretchability. The incorporation of metal-ligand coordination increases the glass transition temperature of the soft middle block without changing the characteristic length of the microphase separation. This convenient and robust method is generally applicable to fabricating various block copolymer-based supramolecular elastomers with enhanced mechanical properties and tunable optical characteristics.