Abstract Robust ultrathin multilayer films of silk fibroin were fabricated by spin coating and spin‐assisted layer‐by‐layer assembly their mechanical properties studied both in tensile compression modes for the first time. The characterized a high elastic modulus 6–8 GPa (after treatment with methanol) ultimate strength reaching 100 MPa. superior toughness is also many times higher than that usually observed conventional polymer composites (328 kJ m –3 material here versus typical values...

Hybrid bimetallic nanocobs, comprising a silver nanowire core surrounded by gold nanoparticle shell linked together star polymer with terminal functional groups, revealed greatly enhanced SERS ability. The enhancement exceeded Raman scattering from isolated nanowires about two orders of magnitude. Effective plasmon excitation provides broad absorption band for activation, which is also directionally dependent, making the nanocobs promising candidates arrayed microstructures.

Abstract A novel type of all‐natural, biocompatible, and very robust nanoscale free‐standing biohybrids are reported. They obtained by integrating a silk fibroin matrix with functional inorganic nanoplatelets using spin‐assisted layer‐by‐layer assembly. The organized assembly the clay (montmorillonite) nanosheets results in highly transparent films significantly enhanced mechanical properties, including strength, toughness, elastic modulus, as compared to those for pristine nanomaterials....

We report the synthesis of novel hyperbranched amphiphilic poly(ethylene oxide)−polystyrene (PEO−PS)n copolymers obtained by controlled radical polymerizations: nitroxide mediated polymerization (NMP) and reversible addition−fragmentation chain transfer (RAFT). The macroinimers used to synthesize have general structure AB*, where A stands for PEO with a terminal double bond B* PS block initiating group (TEMPO or RAFT CTA). Bulk NMP yielded higher molecular weight polydispersity. in solution...

Monitoring trace amounts of peroxide-based molecules is challenging because the lack common optical signatures (fluorescence or absorption in UV−vis range) chemical functionality easily detectable with routines. To overcome this issue, we suggest a photochemical decomposition approach followed by analysis fragments fast, sensitive, and reliable Raman spectroscopic method. facilitate approach, employed novel design surface-enhanced scattering (SERS)-active nanoporous substrate based on porous...

Abstract It is demonstrated that bimetallic silver–gold anisotropic nanostructures can be easily assembled from various nanoparticle building blocks with well‐defined geometries by means of electrostatic interactions. One‐dimensional (1D) silver nanowires, two‐dimensional (2D) nanoplates, and spherical gold nanoparticles are used as representative for bottom‐up assembly. The electrostatically bound onto the 1D nanowires 2D nanoplates to give nanostructures. unique feature resulting...

We report on the surface behavior of asymmetric heteroarm poly(ethylene oxide) (PEO)/polystyrene (PS) star polymer air−water interface a solid substrate. These amphiphilic polymers with different numbers hydrophobic arms and similar hydrophilic block differ by architecture (four three arm molecules, PEO-b-PS3 PEO-b-PS2), length PS chains (molecular weight from about 10 000 up to 24 000), number (three two). Detailed analysis revealed that well-developed circular domain morphology was formed...

Freestanding layer-by-layer (LbL) films encapsulating controlled volume fractions (ϕ = 2.5–22.5 %) of silver nanowires are fabricated. The sandwiched between poly(allylamine hydrochloride)/poly(styrene sulfonate) (PAH/PSS) resulting in nanocomposite structures with a general formula (PAH/PSS)10PAH Ag(PAH/PSS)10PAH. Young's modulus, toughness, ultimate stress, and strain evaluated for supported freestanding structures. Since the diameter (73 nm) is larger than thickness LbL (total about 50...

Silver nanowires functionalized with gold nanoparticles using a polyacrylic acid linker exhibit pH-modulated optical properties, including shift in localized surface plasmon resonance, and triggered surface-enhanced Raman scattering (SERS) effects. The tunable properties are exhibited as result of changes particle coupling caused by the swelling response acid. Detailed facts importance to specialist readers published "Supporting Information". Such documents peer-reviewed, but not copy-edited...

This study probes the behavior of two series organic-functionalized core−shell silsesquioxane (POSS-M)p-(x/y) derivatives with various hydrophobic−hydrophilic terminal group compositions in bulk state and within mono- multilayered films at air−water interface on solid surface. POSS-M refers to mixed cores, contrast geometrically specific POSS compounds. It is composed polyhedra, incompletely condensed ladder-type structures, linear all possible combinations thereof attracts great interest...

Unidirectionally oriented silver nanowires encapsulated into a nanoscale polymeric film result in anisotropic mechanical response of the composite with much stiffer (fivefold) properties direction nanowire orientation. This difference is caused by fact that under longitudinal compressive stress (parallel to orientation), individual undergo buckling process, thus, contributing higher stiffness film. matrix-induced phenomenon can be used as fast and straightforward method measuring elastic...

Luminescent nanophase europium-doped ZrO2 precursors are subjected to pyroprobe heating with nominal rates of 20 000 °C/s for 1 and 10 s various temperatures. When heated above the crystallization temperature, material forms tetragonal monoclinic polymorphs. Optical spectroscopy is used measure excitation spectra, fluorescence lifetimes samples. These optical signatures evaluated their potential as temperature indicators short events. The intensity ratio two peaks appear be promising...

One of the main limitations utilizing optimal wavefront shaping in imaging and authentication applications is slow speed optimization algorithms currently being used.To address this problem we develop a micro-genetic algorithm (µGA) for shaping.We test abilities µGA make comparisons to previous (iterative simple-genetic) by using each optimize transmission through an opaque medium.From our experiments find that faster than both iterative simple-genetic genetic are more resistant noise sample...

Star polymers composed of equal numbers poly(ethylene oxide) (PEO) and polystyrene (PS) arms with variable lengths a large (up to 38 total) number arms, PEOnPSn, have been examined for their ability form domain nanostructures at the air−water air−solid interfaces. All PEOnPSn star formed stable Langmuir−Blodgett (LB) monolayers transferable solid substrate. A range nanoscale surface morphologies observed, ranging from cylindrical circular domains bicontinuous structures as weight fraction...

An intriguing formation of nanoscale buckles is discovered when an array aligned silver nanowires was deposited onto prestrained polydimethylsiloxane substrates. The spacing distance between the resulting nanoparticles corresponds to buckling wavelength nanowires. buckled exhibit unique optical properties, such as interruption scattered polarized photons and emission from subwavelength structure, well surface-enhanced Raman scattering at vicinity formed nanobuckles. In this way, they have...

We fabricated silver nanowire crossbars partially decorated with nanoparticles via a double-step transversal capillary transfer microprinting approach and demonstrated their polarization-dependent surface-enhanced Raman scattering (SERS) properties. that SERS intensity of junctions nanowire−nanoparticle can be turned on/off on demand by the rotation polarization plane, which excites specific plasmon resonances initiates selective excitation/suppression central auxiliary nanostructured...

One of the primary difficulties in implementation organic-dye-based random lasers is tendency organic dyes to irreversibly photodecay. In this letter we report observation "reversible" photodegradation a Rhodamine 6G and ZrO$_2$ nanoparticle doped polyurethane laser. We find that during degradation emission broadens, redshifts, decreases intensity. After system observed self-heal leading returning its pristine intensity, giving recovery efficiency 100%. While peak intensity fully recovers,...

Spatial light modulator (SLM) controlled transmission of through opaque media is a relatively new experimental method with wide applications in various fields. While there has been surge research into the technique, little work reported considering effects parameters on efficiency optimization. In this study, we explore conditions optimization and find that intensity enhancement depends number modulated channels, phase steps, feedback integration radius, beam spot size, active SLM area. We...

We focus on the role of functional terminal group combinations for (X-PEO)2-(PS-Y)2 heteroarm star copolymers with respect to their interfacial behavior and surface morphology. synthesized a series bromine, amine, TBDPS, hydroxyl, carboxylic groups. The study concluded that hydrophilic groups attached hydrophobic chains resulted in stabilization spherical domain morphology, rather than cylindrical morphology predicted given chemical composition copolymers. replacement polymer was found be...

Luminescent europium-doped Y2O3 precursors are evaluated as potential ex situ thermal sensors for rapid heating events. The material is heated via pyroprobe periods between 1 and 100 s. morphological optical properties of the measured a function temperature dwell time. Upon heating, believed to transform according Y2(CO3)3 → Y2O(CO3)2 Y2O2CO3 Y2O3, with transition crystalline phase occurring at about 666 °C. spectra heat-treated samples reflect presence amorphous components. peak excitation...

Optical physical unclonable functions (O-PUFs) are materials containing a large number of randomly distributed degrees freedom that can be probed optically. We develop tamper-indicating O-PUF seals using polyurethane adhesives with dispersed nanoparticles, where authentication is performed by use wavefront-shaping controlled reflection. test the material's and method's ability tampering attacks including: mechanical, thermal, chemical attacks, results demonstrating material/method's robust...