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Polymer electrolytes with bicontinuous nanostructures for lithium metal batteries were prepared by UV-polymerization of hydrophobic domains in microemulsions of ionic liquids, amphiphilic ionic liquids, lithium salts and monomers.

MXene-blanketed Au nanoparticle assembly with energy level alignment effectively facilitates the charge transfer effect while securing the electromagnetic effect by guiding the analyte near to hotspot center for surface enhanced Raman scattering.

The lithium-ion batteries (LIBs) have been extensively developed for improving high energy density, safety, stable lifespans, and cost-effectiveness, which are essential in next-generation mobile electronic devices including cell phone, drone, and electrical vehicles. Polymer electrolytes (PEs) are one of the key components for advanced LIBs with better safety and high energy density. Thus far, several cutting-edge PEs with various structures and functionalities have been developed. In this article, we have summarized recent progress in polymer electrolytes for high-performance LIBs. At first, the ion transport mechanisms, mechanical properties of solid polymer electrolytes and gel polymer electrolytes are discussed. Then, the nanostructured polymeric films as advanced polymer electrolytes will be discussed including lithium-ion conductivity, mechanical properties, and processibility. Finally, we will discuss remaining challenges and future research direction of the nanostructured polymer electrolytes for high-performance LIBs.

The scalable synthetic route to colloidal atoms has significantly advanced over the past two decades. Recently, colloidal clusters with DNA-coated cores called "patchy colloidal clusters" have been developed, providing a directional bonding with specific angle of rotation due to the shape complementarity between colloidal clusters. Through a DNA-mediated interlocking process, they are directly assembled into low-coordination colloidal structures, such as cubic diamond lattices. Herein, the significant progress in recent years in the synthesis of patchy colloidal clusters and their assembly in experiments and simulations is reviewed. Furthermore, an outlook is given on the emerging approaches to the patchy colloidal clusters and their potential applications in photonic crystals, metamaterials, topological photonic insulators, and separation membranes.

Nanophotonics relies on precise control of refractive index (RI) which can be designed with metamaterials. Plasmonic superstructures of nanoparticles (NPs) can suggest a versatile way of tuning RI. However, the plasmonic effects in the superstructures demand 1 nm-level exquisite control over the interparticle gap, which is challenging in a sub-wavelength NPs. Thus far, a large-area demonstration has been mostly discouraged. Here, heteroligand AuNPs are prepared, which are stable in oil but become Janus particles at the oil-water interface, called "adaptive Janus particles." NPs are bound at the interface and assembled into 2D arrays over square centimeters as toluene evaporates, which distinctively exhibits the RI tunability. In visible and NIR light, the 2D superstructures exhibit the highest-ever RI (≈7.8) with varying the size and interparticle gap of NPs, which is successfully explained by a plasmonic percolation model. Furthermore, fully solution-processable 2D plasmonic superstructures are proved to be advantageous in flexible photonic devices such as distributed Bragg reflectors.

Continuous synthesis of polymeric nanoparticles (NPs) has been intensively studied due to its great potential to produce NPs with the physicochemical properties of reproducibility and controllability. Here, we developed a self-aligned coaxial turbulent jet mixer for high-speed continuous synthesis of polymeric NPs. The coaxial turbulent jet mixer can be constructed using commercial tube fittings and tubes. Since those fluidic components are self-aligned coaxially, leak-free jet mixers can be assembled without the use of tools or specialized skills in robust manner. Using the jet mixer with polystyrene (PS) solution, uniform polymeric NPs can be synthesized in a fully continuous manner, for which diaphragm pumps and pulsation dampers are used for continuous control of the flow. We also improved the dispersion stability of the PS NPs in aqueous solution against centrifugation by introducing polystyrene-poly(ethylene oxide) diblock copolymer (PS-b-PEO) as steric stabilizer. The NPs prepared using the coaxial turbulent jet mixer were smaller and more uniform in size compared to NPs synthesized by a bulk nanoprecipitation method.

The molecular weights and chain rigidities of block copolymers can strongly influence their self-assembly behavior, particularly when the block copolymers are under confinement. We investigate the self-assembly of bottlebrush block copolymers (BBCPs) confined in evaporative emulsions with varying molecular weights. A series of symmetric BBCPs, where polystyrene (PS) and polylactide (PLA) side-chains are grafted onto a polynorbornene (PNB) backbone, are synthesized with varying degrees of polymerization of the PNB (

Colloidal photonic crystals show structural colors yet are generally opaque due to multiple scattering. To address this problem, composite colloidal crystals with a low index mismatch were prepared...

We describe a general procedure for the large-scale fabrication of bowl-shaped colloidal particles using an emulsion templating technique. Following this method, single polymeric seed particles become located on individual oil droplet surfaces. The polymer phase is subsequently plasticized using an appropriate solvent. In this critical step, the compliant seed is deformed by surface tension, with the droplet serving as a templating surface. Solvent evaporation freezes the desired particle shape and the oil is subsequently removed by alcohol dissolution. The resulting uniformly-shaped colloidal particles were studied using scanning electron and optical microscopy. By adjusting the droplet size and the seed particle diameter, we demonstrate that the final particle shape can be controlled precisely, from shallow lenses to deep bowls. We also show that the colloid's uniformity and abundant quantity allowed the depletion-mediated assembly of flexible colloidal chains and clusters.

DNA-mediated colloidal interactions provide a powerful strategy for the self-assembly of ordered superstructures. We report a practical and efficient two-step chemical method to graft DNA brushes onto carboxylated particles, which resolves the previously reported issues such as irreversible aggregation, inhomogeneous coating, and relatively low DNA density that can hinder colloidal crystallization. First, carboxylated particles are functionalized with heterobifunctionl polyethylene glycol (NH2-PEGn-N3) by DMTMM-activated esterification of carboxylic groups and amide coupling. Then, DBCO-functionalized DNA strands are grafted onto the pegylated particles through strain-promoted alkyne-azide cycloaddition (SPAAC) on azide groups. The homogeneous PEG brushes provide dispersion stability to the particles and clickable functional groups, resulting in DNA coatings of 1,100,000 DNA per 1-µm particle or 1 DNA per 2.9 nm2, about five times higher than previously reported. The DNA-coated particles exhibit a sharp a...

Binary inorganic nanoparticles (NPs) can be assembled into various types of superlattices depending on the size ratio, shape, and interparticle potential, which may tailor the mechanical, optical and electronic properties. Here, polymer-stabilized gold NPs are assembled into binary nanoparticle superlattices (BNSLs) and their structures were precisely controlled by tuning the size ratio of NPs as well as the chain length of polymer ligands. Typically, binary gold NPs with short-chain polymer ligands showed the phase behaviors of hard-sphere colloids. By contrast, ones with long-chain polymer ligands showed the phase behavior of soft-sphere binary colloids. Interestingly, mixed binary NPs with short-chain and long-chain polymer ligands showed unnatural binary NP superlattices in thin films, in which small NPs are contained in octahedral voids of the regular HCP lattice. Our finding can be further extended to other types of functional NPs, which may tune various properties for devices.

The prime example of a two-dimensional photonic crystal featuring Dirac cones is based on the honeycomb lattice. Colloidal self-assembly can produce a two-dimensional colloidal structure over a large area but is limited to hexagonal-close-packed structures. Therefore, it has been challenging to fabricate honeycomb monolayers by colloidal self-assembly. Here, we fabricate a dielectric honeycomb lattice in a large area by template-assisted self-assembly and analyze its photonic structure. Although the Dirac point occurring at the K point is not accessible by light in free space, a part of the upper Dirac cone above the light line is verified by a Fourier analysis of the back-focal-plane image. Because the template-assisted self-assembly enables additional geometrical perturbations in the honeycomb lattice, various lattices can be fabricated. This additional degree of freedom may provide an alternative way of fabricating photonic topological insulators.

Colloidal clusters are prepared by assembling positively charged cross-linked polystyrene (PS) particles onto negatively charged liquid cores of swollen polymer particles. PS particles at the interface of the liquid core are closely packed around the core due to interfacial wetting. Then, by evaporating solvent in the liquid cores, polymers in the cores are solidified and the clusters are cemented. As the swelling ratio of PS cores increases, cores at the center of colloidal clusters are exposed, forming patchy colloidal clusters. Finally, by density gradient centrifugation, high-purity symmetric colloidal clusters are obtained. When silica-PS core-shell particles are swollen and serve as the liquid cores, hybrid colloidal clusters are obtained in which each silica nanoparticle is relocated to the liquid core interface during the swelling-deswelling process breaking symmetry in colloidal clusters as the silica nanoparticle in the core is comparable in size with the PS particle in the shell. The configuration of colloidal clusters is determined once the number of particles around the liquid core is given, which depends on the size ratio of the liquid core and shell particle. Since hybrid clusters are heavier than PS particles, they can be purified using centrifugation.

We prepared BaSnF4 nanowires (NWs) with a high dielectric constant using a simple high-energy ball-milling method and investigated the dielectric properties of polymer composites containing inorganic fluoride fillers. We employed various techniques, such as powder X-ray diffraction, scanning and transmission electron microscopy, and elemental mapping analysis using energy-dispersive X-ray spectroscopy, and we showed that the morphology of BaSnF4 changed from microparticles consisting of aggregated flakes to NWs as applied kinetic energy increased. A comparison of composite films containing two fillers confirmed that the dielectric constant and AC conductivity of BaSnF4 NWs at 30 vol % were two to three times higher than those of aggregated nanoparticles. Even though the breakdown strength was low at a high volume fraction, these results indicate that BaSnF4 NWs are extremely promising materials for the development of high-κ nanocomposites for various dielectric applications.

Controlling the complex dynamics of active colloids-the autonomous locomotion of colloidal particles and their spontaneous assembly-is challenging yet crucial for creating functional, out-of-equilibrium colloidal systems potentially useful for nano- and micromachines. Herein, by introducing the synthesis of active "patchy" colloids of various low-symmetry shapes, we demonstrate that the dynamics of such systems can be precisely tuned. The low-symmetry patchy colloids are made in bulk via a cluster-encapsulation-dewetting method. They carry essential information encoded in their shapes (particle geometry, number, size, and configurations of surface patches, etc.) that programs their locomotive and assembling behaviors. Under AC electric field, we show that the velocity of particle propulsion and the ability to brake and steer can be modulated by having two asymmetrical patches with various bending angles. The assembly of monopatch particles leads to the formation of dynamic and reconfigurable structures such as spinners and "cooperative swimmers" depending on the particle's aspect ratios. A particle with two patches of different sizes allows for "directional bonding", a concept popular in static assemblies but rare in dynamic ones. With the capability to make tunable and complex shapes, we anticipate the discovery of a diverse range of new dynamics and structures when other external stimuli (e.g., magnetic, optical, chemical, etc.) are employed and spark synergy with shapes.

We prepared F-coated rutile titanium dioxide nanoparticles (r-TiO2 NPs) via simple thermal annealing of titania NPs in poly(vinylidene fluoride) (PVDF) and demonstrated that the F-coated r-TiO2 NP-...

To produce flame resistant poly(acrylonitrile-co-vinyl chloride) (PANVC) fibers (limiting oxygen index (LOI)> 28%) for flame retardant work wear, PANVC solutions containing antimony trioxide (ATO) and zinc hydroxystannate (ZHS) flame retardants at various composition ratios were wet spun using laboratory-scale equipment. The amount of ATO and ZHS added was determined to be 15 phr using the thin material vertical burning test. The LOI values of PANVC increased considerably from 27.9% to 33.1% with increasing ZHS composition ratio, but no significant synergistic effects were observed between ATO and ZHS. With increasing ZHS composition ratio, more densified structures of the char layer were observed after combustion. ZHS was found to be a more effective and suitable flame retardant for PANVC than ATO. The PANVC fibers had a round cross section and the ATO and ZHS particles were distributed uniformly in the PANVC fibers. The presence of ATO and ZHS particles decreased the tenacities of the pure PANVC fibers slightly.

We prepared a high-concentration suspension of boron nitride (BN) nanoplates stabilized with benzyl alcohol (B-BN) in epoxy resin as a polymer composite adhesive for a highly efficient heat dissipation. At a BN concentration of 40 wt%, the polymer composite with B-BN exhibited a high thermal conductivity (κ = 1.51 W/m·K at 25 °C) comparable to that of a composite with bulk BN and significantly higher than that of a composite with a chemically modified BN (S-BN). Furthermore, the concentration of B-BN in the epoxy resin was increased to 46 wt% without a significant increase in viscosity, leading to a further improvement in the thermal conductivity to 2.11 W/m·K. The epoxy resin with B-BN exhibited a low coefficient of thermal expansion and high effective modulus owing to the strong affinity to the epoxy. Finally, we recycled benzyl alcohol more than 10 times for the preparation of B-BN, which may reduce the manufacturing cost and environmental pollution. Therefore, B-BN could be a promising filler for heat dissipation as well as starting material for additional modification.

Radiotherapy has been a central part in curing non-small cell lung cancer (NSCLC). However, it is possible that not all of the tumor cells are destroyed by radiation; therefore, it is important to effectively control residual tumor cells that could become aggressive and resistant to radiotherapy. In this study, we aimed to investigate the molecular mechanism of decreased NSCLC radioresistance by low-dose radiation (LDR) pretreatment. The results indicated that miR-30a and miR-30b, which effectively inhibited plasminogen activator inhibitor-1 (PAI-1), were overexpressed by treatment of LDR to NSCLC cells. Phosphorylation of Akt and ERK, the downstream survival signals of PAI-1, was decreased by PAI-1 inhibition. Reduced cell survival and epithelial-mesenchymal transition by PAI-1 inhibition were confirmed in NSCLC cells. Moreover, in vivo orthotopic xenograft mouse models with 7C1 nanoparticles to deliver miRNAs showed that tumor growth and aggressiveness were efficiently decreased by LDR treatment followed by radiotherapy. Taken together, the present study suggested that PAI-1, whose expression is regulated by LDR, was critical for controlling surviving tumor cells after radiotherapy.

Gold nanoparticles are widely exploited for biological and biotechnical applications owing to their stability, biocompatibility, and known effects on cellular behaviors. Many studies have focused on nanoparticles that are internalized into cells, but extracellular nanoparticles also can regulate cell behavior, a practice known as in-plane surface nanotopography. We demonstrated that nanobarriers composed of morphologically homogeneous gold nanospheres prolonged the mitotic (M) phase in the cervical cancer cell line HeLa without inducing apoptosis. The nanobarrier was formed by electrostatic deposition of nanospheres on a negatively charged, fibronectin-coated substrate. We tested the effects of differently sized nanospheres. Gold nanospheres 42 nm in diameter were found to be non-toxic, while 111 nm nanospheres induced the production of reactive oxygen species, resulting in apoptotic cell death and arrest of cytokinesis. When exposed to sufficient 83 nm gold nanospheres to fabricate a surface nanobarrier, the M phase was delayed but cells proceeded to cytokinesis and the G1 phase. Live-cell imaging showed that the M phase increased by 2.9 h, 2.4 times longer than in control cells. Biophysical analyses indicated that this could be attributed to the specific size of the nanobarrier that physically limited the growth area around the cell.

Large volumetric expansion and structural pulverization have been major problems in Si-based anode materials for Li-ion batteries. To overcome this limitation, yolk-shell structured Si-carbon structures have been proposed to allow for the reversible structural breathing of Si nanoparticles confined inside the carbon shell. However, initial coulombic efficiency (ICE) of the yolk-shell structured anodes is highly decreased mainly due to their extremely high specific surface area (SSA) and the resulting excessive formation of solid electrolyte interphase (SEI) over the carbon shell. Here, instead of using a single Si nanoparticle-containing yolk-shell structure, we propose a novel structure comprising hollow carbon capsules internally encapsulating Si nanoparticle clusters (SNC@Cs). To implement this structural design, Si nanoparticle clusters are encompassed by a polystyrene matrix (SNC@PS) by emulsion polymerization, followed by coating with a polydopamine (PDA) layer (SNC@PS@PDA). Then, after annealing them for carbonization, SNC@Cs are finally prepared, which can decrease the SSA by a factor of one-third compared to the conventional yolk-shell structures. These SNC@C particles have shown remarkably high ICE values of up to 81%. Moreover, the cycling stability could be improved up to 100 cycles because the properly confined Si cluster inside the stable carbon capsule mitigates structural pulverization during repeated lithiation-delithiation processes of Si nanoparticles.

Gold nanoparticles (AuNPs) have been widely used as nanocarriers in drug delivery to improve the efficiency of chemotherapy treatment and enhance early disease detection. The advantages of AuNPs include their excellent biocompatibility, easy modification and functionalization, facile synthesis, low toxicity, and controllable particle size. This study aimed to synthesize a conjugated citraconic anhydride link between morphologically homogeneous AuNPs and doxorubicin (DOX) (DOX-AuNP). The carrier was radiolabeled for tumor diagnosis using positron emission tomography (PET). The systemically designed DOX-AuNP was cleaved at the citraconic anhydride linker site under the mild acidic conditions of a cancer cell, thereby releasing DOX. Subsequently, the AuNPs aggregated via electrostatic attraction. HeLa cancer cells exhibited a high uptake of the radiolabeled DOX-AuNP. Moreover, PET tumor images were obtained using radiolabeled DOX-AuNP in cancer xenograft mouse models. Therefore, DOX-AuNP is expected to provide a valuable insight into the use of radioligands to detect tumors using PET.

Coating colloidal particles with DNA provides one of the most versatile and powerful methods for controlling colloidal self-assembly. Previous studies have shown how combining DNA coatings with DNA strand displacement allows one to design phase transitions between different three-dimensional crystal structures. Here we show that by using DNA coatings with bifunctional colloidal Janus particles, we can realize reconfigurable thermally reversible transitions between one- and two-dimensional self-assembled colloidal structures. We introduce a colloidal system in which DNA-coated asymmetric Janus particles can reversibly switch their Janus balance in response to temperature, resulting in the reconfiguration of assembling structures between colloidal chains and bilayers. Each face of the Janus particles is coated with different self-complementary DNA strands. Toehold strand displacement is employed to selectively activate or deactivate the sticky ends on the smaller face, which enables Janus particles to selectively assemble through either the smaller or larger face. This strategy could be useful for constructing complex systems that could be reconfigured to assemble into different structures in different environments.

Confining light in extremely small cavities is crucial in nanophotonics, central to many applications. Employing a unique nanoparticle-on-mirror plasmonic structure and using a graphene film as a spacer, we create nanoscale cavities with volumes of only a few tens of cubic nanometers. The ultracompact cavity produces extremely strong optical near-fields, which facilitate the formation of single carbon quantum dots in the cavity and simultaneously empower the strong coupling between the excitons of the formed carbon quantum dot and the localized surface plasmons. This is manifested in the optical scattering spectra, showing a magnificent Rabi splitting of up to 200 meV under ambient conditions. In addition, we demonstrate that the strong coupling is tuneable with light irradiation. This opens new paradigms for investigating the fundamental light emission properties of carbon quantum dots in the quantum regime and paves the way for many significant applications.

DNA is a unique molecule for storing information, which is used to provide particular biological instructions. Its function is primarily determined by the sequence of its four nucleobases, which have highly specific base-pairing interactions. This unique feature can be applied to direct the self-assembly of colloids by grafting DNA onto them. Due to the sequence-specific interactions, colloids can be programmed with multiple instructions. Here, we show that particles having multiple DNA strands with different melting profiles can undergo multiple phase transitions and reassemble into different crystalline structures in response to temperature. We include free DNA strands in the medium to selectively switch on and off DNA hybridization depending on temperature. We also demonstrate that DNA hybridization kinetics can be used as a means to achieve targeted assembling structure of colloids. These transitions impart a reconfigurability to colloids in which systems can be transformed an arbitrary number of times using thermal and kinetic control.

International audience; Self-assembling colloidal particles in the cubic diamond crystal structure could potentially be used to make materials with a photonic bandgap 1-3. Such materials are beneficial because they suppress spontaneous emission of light 1 and are valued for their applications as optical waveguides, filters and laser resonators 4 , for improving light-harvesting technologies 5-7 and for other applications 4,8. Cubic diamond is preferred for these applications over more easily self-assembled structures, such as face-centred-cubic structures 9,10 , because diamond has a much wider bandgap and is less sensitive to imperfections 11,12. In addition, the bandgap in diamond crystals appears at a refractive index contrast of about 2, which means that a photonic bandgap could be achieved using known materials at optical frequencies; this does not seem to be possible for face-centred-cubic crystals 3,13. However, self-assembly of colloidal diamond is challenging. Because particles in a diamond lattice are tetrahedrally coordinated, one approach has been to self-assemble spherical particles with tetrahedral sticky patches 14-16. But this approach lacks a mechanism to ensure that the patchy spheres select the staggered orientation of tetrahedral bonds on nearest-neighbour particles, which is required for cubic diamond 15,17. Here we show that by using partially compressed tetrahedral clusters with retracted sticky patches, colloidal cubic diamond can be self-assembled using patch-patch adhesion in combination with a steric interlock mechanism that selects the required staggered bond orientation. Photonic bandstructure calculations reveal that the resulting lattices (direct and inverse) have promising optical properties, including a wide and complete photonic bandgap. The colloidal particles in the self-assembled cubic diamond structure are highly constrained and mechanically stable, which makes it possible to dry the suspension and retain the diamond structure. This makes these structures suitable templates for forming high-dielectric-contrast photonic crystals with cubic diamond symmetry.

International audience; The fixation of hydrogels to biological tissues is a major challenge conditioning the development of implants and surgical techniques. Here, coatings of procoagulant nanoparticles are devised which use the presence of blood to create adhesion between hydrogels and soft internal organs. Those nanostructured coatings are simply adsorbed at the hydrogel surfaces and can rapidly activate the formation of an interfacial blood clot acting as an adhesive joint. This concept is demonstrated on pig liver capsules with model poly(ethylene-glycol) membranes that are intrinsically poorly adhesive. In the absence of blood, ex vivo peeling tests show that coatings with aggregates of bare silica nanoparticles induce a 2- to 4-fold increase in adhesion energy as compared to the uncoated membrane (3 ± 2 J m–2). This effect is found to scale with the specific surface area of the coating. The highest adhesion energies produced by these nanoparticle-coated membranes (10 ± 5 J m–2) approach the value obtained with cyanoacrylate glue (33 ± 11 J m–2) for which tearing of the tissue is observed. Ex vivo pull-off tests show an adhesion strength of coated membranes around 5 ± 1 kPa, which is significantly reduced when operating in vivo (1.0 ± 0.5 kPa). Nevertheless, when blood is introduced at the interface, the in vivo adhesion strength can be improved remarkably with silica coatings, reaching 4 ± 2 kPa after 40 min contact. In addition, these silica-coated membranes can seal and stop the bleeding produced by liver biopsies very rapidly (

Porous and electrically conductive coating on silicon nanoparticles (Si NPs) anode can mitigate the volume expansion during charging or discharging in Li-ion battery (LIB) while conventional protection coating process resulted in non-uniform polymer shell which show low volumetric or areal capacities. Here, we demonstrated that ultra-thin polyacrylonitrile layer can be formed conformally by emulsion-assisted coating process and cross-linked on Si NPs (Si@x-PAN) producing stable and expandable polymer shell which showed a highly stable long-term cycling ability. Areal and specific capacities of Si@x-PAN were an ∼ 2 mAh/cm2 and a 2000 mAh/g, respectively. Importantly, we found that capacity decay was only 5 % after 100 cycles and>75 % of capacity was retained even after 1000 cycles (0.5C/0.5C) with the help of a uniform Li-ion current around the Si NPs during continuous charging and discharging. To our knowledge, this long-term stability at reasonable loading levels is one of the highest levels of performance in pure Si anode systems.

Reversible and specific interaction between single-stranded DNA on colloidal particles have opened up a new path way of building up colloidal superstructures. DNA-coated microspheres can be bound with other particles with complementary DNA brushes below the melting temperature and can be unbound above the melting temperature. However, due to their random Brownian motion, the particles form random (or glassy) structures in most cases or small crystals when cooling is extremely slow. Therefore, toward programmed colloidal superstructures of DNA-coated microspheres, they should reconfigure their kinetically trapped random structure to equilibrium crystalline structures. While nanoparticles can be rearranged into a crystalline structure by a simple conformational change of relatively long DNA brush, microspheres with short DNA brushes cannot be rearranged only by a conformational change of brush. Instead, sub-diffusion of bound DNA-coated microspheres is necessary which can be possible only with uniform DNA coating with high areal density on microspheres. In this article, we have reviewed methods for the synthesis of high-density DNA-coated microspheres and their assembly into crystalline structures. We also discuss future research direction of DNA-coated microspheres.

Transparent conductive electrodes (TCEs), which offer advantages of high electrical conductivity and optical transparency, are essential components of practical high-tech optoelectronics such as touch panels, e-papers, organic light-emitting diodes, and solar cells. Solution-processed Ag nanowires (AgNWs) have been considered as a practical alternative TCE material suitable for industrial-scale mass production. However, the contact resistance at AgNW junctions strongly affects the total sheet resistance of AgNW electrodes. In recent years, various welding techniques for AgNW network electrodes have been developed with the aim of decreasing their sheet resistance while maintaining their optical transmittance. In this paper, we present a review of various welding methods such as thermal-mechanical welding, light welding, chemical welding, and metal-plating welding.

Crosslinked organosilicon-acrylate copolymer thin film with desired chemical composition was successfully fabricated by a simply modified initiated chemical vapor deposition (iCVD) process. Unlike the conventional iCVD copolymerization process, in our novel process, comonomers were injected together as one gas phase into the polymerization chamber from miscible liquid comonomer mixture. 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (V4D4) and cyclohexyl methacrylate (CHMA) were used as the comonomers and tert-butyl peroxide was used as the initiator. From Fourier transform infrared (FTIR) spectra and solvent resistance test, we clearly confirmed that the crosslinked copolymer thin film with desired chemical composition could be obtained by controlling only the mixing ratio of liquid comonomers. It is expected that crosslinkable V4D4 organosilicon moiety provides hydrophobic moisture barrier property and CHMA acrylate moiety provides mechanical flexibility and better adhesion. We observed a certain level of moisture blocking capability of the copolymer thin film, implying potential application of the crosslinked organosilicon-acrylate copolymer thin film as flexible polymer buffer layer in organic/inorganic or metal oxide hybrid moisture barrier for flexible display or electronic devices.

Monodispersed thermally stable aqueous emulsions were generated in perfluorocarbon oil with penta-block copolymers of fluorocarbon and poly(ethylene oxide-b-propylene oxide-b-ethylene oxide), which are controlled in guided channels of microfluidic devices, which were essentially the protrusion on top of microfluidic channels. Aqueous emulsions could stably follow the guide channels and sequentially stored at dead ends of guide channels. Depending on the size ratio of emulsion to trapping region, one or two emulsions were stored in two-dimensional arrays on demand. By adding pneumatic valve actuators on top of guide channel, they could be stored or released on demand or as programmed. Furthermore, by encapsulating colloidal particles and Hela cells in the thermally stable water-in-perfluorocarbon emulsions, we demonstrated that particle-laden and cellladen emulsions could be manipulated in controlled and programmed manner.

Aspherical cubic hematite colloids with cylindrical arms protruding from each face, referred to as "hexapods", were assembled via negative dielectrophoresis and then manipulated using an applied magnetic field. Upon application of an ac electric field, the hexapods aligned in close-packed linear chains parallel to the field direction. The chains then aggregated to the center of the device, with adjacent chains separated by distances approximately equal to twice the arm length. The resulting open packing structure exhibited cmm plane group symmetry due to the obstruction of arms, with a high density of incorporated defects. Subsequent application of a magnetic field to the dielectrophoresis (DEP)-assembled structure was found to anneal the colloidal crystal by reorienting the hexapods to align their intrinsic magnetic dipoles with the magnetic field direction. During reorganization, the colloidal packing density was found to decrease by more than 10% at both the center and edges of the crystal, accompanied by a significant loss of ordering, prior to redensification of the 2D lattice with fewer defects. Reorganization at the edge was 1.5 times faster than at the center, consistent with the need for cooperative colloidal motion to remove defects at the centers of the crystals.

Improvement in the rate capability needs to be addressed for utilization of a Si anode in high-power Li-ion batteries. Regarding the rate capability, its improvement by Si–C nanocomposites seems to be somewhat saturated, thus indicating that the other method should be tried for further enhancement of the rate capability. Here, we introduce Si nanoparticles uniformly coated with nanometer-thick polyacrylonitrile (PAN) with better wettability to liquid electrolytes and minimizing electronic resistance, which might result from a thick PAN coating: the effective contact surface area made by the contact of Si nanoparticles and liquid electrolyte is increased for larger Li-ion current, leading to ultrafast rate capability retaining 62% of the 0.2C rate discharge capacity at 100C. In addition, a strong adhesive property of PAN provides highly mechanically robust Si anodes for multielectrode-stacked flexible lithium-ion batteries, which show no physical damage after 30 000 bending cycles with a bending radius of ...

Carbon-embedded ordered macroporous titania (C-MAC TiO2) spheres are prepared in solution by the cooperative self-assembly of polymer beads and a titania precursor within evaporative emulsions and subsequent direct carbonization. Because the highly reactive titania precursors are easily crosslinked to form gels early in evaporation before the polymer beads are self-organized, non-reactive toluene-in-formamide emulsions are used. These non-aqueous emulsions should be stable at relatively high temperatures (~80 °C) for the evaporation process. We found that amphiphilic triblock copolymers of poly(ethylene oxide) (PEO) and poly(phenylene oxide) (PPO) with longer PEO chains (Pluronic® F108 (EO125-b-PO64-b-EO125) are required to stabilize those non-aqueous emulsions, and become more important at higher concentrations used for bulk fabrication. The carbon inside our C-MAC TiO2 significantly suppresses strong multiple scattering from structural defects or imperfections, thus emphasizing their Bragg reflection colors.

DNA-mediated self-assembly of colloidal particles is one of the most promising approaches for constructing colloidal superstructures. For nanophotonic materials and devices, DNA-functionalized colloids with diameters of around 100 nm are essential building blocks. Here, we demonstrate a strategy for synthesizing DNA-functionalized polymer nanoparticles (DNA-polyNPs) in the size range of 55–150 nm using block copolymer micelles as a template. Diblock copolymers of polystyrene-b-poly(ethylene oxide) with an azide end group (PS-b-PEO-N3) are first formed into spherical micelles. Then, the micelle cores are swollen with the styrene monomer and polymerized, thus producing PS NPs with PEO brushes and azide functional end groups. DNA strands are conjugated onto the ends of the PEO brushes through a strain-promoted alkyne–azide cycloaddition reaction, resulting in a DNA density of more than one DNA strand per 12.6 nm2 for 70 nm particles. The DNA-polyNPs with complementary sequences enable the formation of CsCl-t...

Block copolymers (BCPs) confined in evaporative emulsions can assemble into ellipsoidal particles when solvent evaporation is faster than polymer diffusion within the droplet. Here, we report the synthesis of monodisperse, ellipsoidal polystyrene-block-1,4-polybutadiene (PS-b-PB) BCP particles with tunable aspect ratios (ARs) ranging from 1.0 to 2.2 and particle sizes ranging from 0.1 to 5 μm by membrane emulsification and subsequent solvent evaporation. The ratio of the propagation distance (lp) of ordered BCP domains perpendicular to the particle surface to the particle size (rBCP), or lp/rBCP, was found to be a critical parameter dictating the particle shape, where lp/rBCP > 1 yielded ellipsoids. We show that the AR of colloidal BCP ellipsoids can be precisely controlled by varying particle size (i.e., membrane pore size) and BCP molecular weight, as predicted by theoretical calculations of the free energy of particle elongation including three terms: (1) the interfacial energy between the two blocks o...