pH- and sugar-induced shape memory hydrogel based on reversible phenylboronic acid-diol ester bonds.

A simple strategy is provided to construct a novel pH- and sugar-induced shape memory hydrogel based on dynamic phenylboronic acid (PBA)-diol interactions formed by PBA-modified sodium alginate (Alg-PBA) and poly(vinyl alcohol) (PVA). The dynamic PBA-diol ester bonds serve as temporary cross-links and stabilize the deformed shape of the hydrogel. The disassociation of the PBA-diol ester bonds is explored in acidic conditions and aqueous solutions of glucose and fructose, which endow the hydrogel with shape memory performances.

Highly thermostable, flexible, transparent, and conductive films on polyimide substrate with an AZO/AgNW/AZO structure.

Flexible transparent conductive films (TCFs) are used in a variety of optoelectronic devices. However, their use is limited due to poor thermostability. We report hybrid TCFs incorporation in both aluminum-doped zinc oxide (AZO) and silver nanowires (AgNWs).

Inorganic photosensitizer coupled Gd-based upconversion luminescent nanocomposites for in vivo magnetic resonance imaging and near-infrared-responsive photodynamic therapy in cancers.

Inorganic photosensitizer coupled Gd-based upconversion luminescent (UCL) nanocomposites have potential application for both magnetic resonance imaging (MRI) and photodynamic therapy (PDT) of cancers using the light stability and biocompatibility of TiO2 inorganic photosensitizer. However, TiO2 inorganic photosensitizer could only be excited by ultraviolet (UV) light, which was harmful and weakly penetrable in tissues. In this work, folic acid (FA)-targeted NaGdF4:Yb/Tm@SiO2@TiO2 nanocomposites (FA-Gd-Si-Ti NPs) were constructed and synthesized for both in vivo MRI and near infrared (NIR)-responsive inorganic PDT, in which TiO2 component could be excited by NIR light due to the UCL performance of NaGdF4:Yb/Tm component converting NIR to UV light.

Skyrmion-skyrmion and skyrmion-edge repulsions in skyrmion-based racetrack memory.

Magnetic skyrmions are promising for building next-generation magnetic memories and spintronic devices due to their stability, small size and the extremely low currents needed to move them. In particular, skyrmion-based racetrack memory is attractive for information technology, where skyrmions are used to store information as data bits instead of traditional domain walls. Here we numerically demonstrate the impacts of skyrmion-skyrmion and skyrmion-edge repulsions on the feasibility of skyrmion-based racetrack memory.

Light-triggered reversible self-assembly of gold nanoparticle oligomers for tunable SERS.

A photoresponsive amphiphilic gold nanoparticle (AuNP) is achieved through the decoration of AuNP with hydrophilic poly(ethylene glycol) (PEG) and hydrophobic photoresponsive polymethacrylate containing spiropyran units (PSPMA). Owing to the photoresponsive property of spiropyran units, the amphiphilic AuNPs can easily achieve the controllable assembly/disassembly behaviors under the trigger by light. Under visible light, spiropyran units provide weak intermolecular interactions between neighbored AuNPs, leading to isolated AuNPs in the solution.

CTAB micelles assisted rGO-AgNP hybrids for SERS detection of polycyclic aromatic hydrocarbons.

A structure of hexadecyl trimethyl ammonium bromide (CTAB) micelle-assisted reduced graphene oxide-Ag nanoparticle (rGO-AgNP) hybrids is designed and fabricated for SERS detection of nonpolar polycyclic aromatic hydrocarbons (PAHs), in which CTAB micelles act as the host material to capture PAH molecules. This method provides stable aqueous suspensions of functionalized graphene with an alkyl chain, since the rGO-AgNP hybrids do not need to be pre-modified by CTAB. The result shows that the CTAB-assisted rGO-AgNP substrate has excellent SERS performance toward PAHs and ideal stability under continuous laser radiation.

CO2 and temperature dual responsive "Smart" MXene phases.

A robust strategy is explored to graft poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes on two-dimensional vanadium carbide (V2C) materials through self-initiated photografting and photopolymerization (SIPGP). CO2 and temperature dual-responsive properties of PDMAEMA allow this hybrid to be used as a smart system for tuning the transmittance and conductivity of V2C.

Novel permanent magnet linear motor with isolated movers: analytical, numerical and experimental study.

This paper proposes a novel permanent magnet linear motor possessing two movers and one stator. The two movers are isolated and can interact with the stator poles to generate independent forces and motions. Compared with conventional multiple motor driving system, it helps to increase the system compactness, and thus improve the power density and working efficiency.

An orientation measurement method based on Hall-effect sensors for permanent magnet spherical actuators with 3D magnet array.

An orientation measurement method based on Hall-effect sensors is proposed for permanent magnet (PM) spherical actuators with three-dimensional (3D) magnet array. As there is no contact between the measurement system and the rotor, this method could effectively avoid friction torque and additional inertial moment existing in conventional approaches. Curved surface fitting method based on exponential approximation is proposed to formulate the magnetic field distribution in 3D space.

Preparation and characterization of highly cross-linked polyimide aerogels based on polyimide containing trimethoxysilane side groups.

In this study, highly cross-linked and completely imidized polyimide aerogels were prepared from polyimide containing trimethoxysilane side groups, which was obtained as the condensation product of polyimide containing acid chloride side groups and 3-aminopropyltrimethoxysilane. After adding water and acid catalyst, the trimethoxysilane side groups hydrolyzed and condensed one another, and a continuous increase in the complex viscosities of the polyimide solutions with time was observed. The formed polyimide gels were dried by freeze-drying from tert-butyl alcohol to obtain polyimide aerogels, which consisted of a three-dimensional network of polyimide fibers tangled together.

Bicontinuous zeolitic imidazolate framework ZIF-8@GO membrane with enhanced hydrogen selectivity.

Through layer-by-layer (LBL) deposition of a graphene oxide (GO) suspension on a semicontinuous ZIF-8 layer, we have developed a novel bicontinuous ZIF-8@GO membrane. Since only the gaps between the ZIF-8 crystals are sealed by the GO layer due to capillary forces and covalent bonds, the gas molecules can only permeate through the ZIF-8 micropore system (0.34 nm).

Solvents induced ZnO nanoparticles aggregation associated with their interfacial effect on organic solar cells.

ZnO nanofilm as a cathode buffer layer has surface defects due to the aggregations of ZnO nanoparticles, leading to poor device performance of organic solar cells. In this paper, we report the ZnO nanoparticles aggregations in solution can be controlled by adjusting the solvents ratios (chloroform vs methanol). These aggregations could influence the morphology of ZnO film.

Effect of stoichiometry on the magnetocrystalline anisotropy of Fe-Pt and Co-Pt from first-principles calculation.

The effect of stoichiometry on magnetocrystalline anisotropy energy (MAE) of Fe1+xPt1-x and Co1+xPt1-x (-0.5 < x < 0.5) is studied by use of first-principles method.

Janus polymer/carbon nanotube hybrid membranes for oil/water separation.

A robust and simple method is provided to fabricate Janus polymer/carbon nanotube (CNT) hybrid membranes for oil/water separation. Starting from CNT membranes formed by dispensing, hydrophobic poly(styrene) (PS) and hydrophilic poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) were grated from different sides of the photoactive CNT membranes via self-initiated photografting and photopolymerization (SIPGP) to achieve Janus polymer/CNTs hybrid membranes. The obtained membranes have excellent oil/water selectivity in the removal of oil from water.

Self-healable macro-/microscopic shape memory hydrogels based on supramolecular interactions.

A simple strategy is provided to construct novel supramolecular hydrogels with both self-healing and shape memory properties. Starting from achieving self-healable hydrogel based on the dynamic interactions of phenylboronic acid modified sodium alginate (Alg-PBA) and poly(vinyl alcohol) (PVA), further formation of a complex of alginate with Ca(2+) renders this hydrogel with the capability of shape memory at the macro-/microscopic scales.

Correlation of intercalation potential with d-electron configurations for cathode compounds of lithium-ion batteries.

The d-electron localization is widely recognized as important to transport properties of transition metal compounds, but its role in the energy conversion of intercalation reactions of cathode compounds is still not fully explored. In this work, the correlation of intercalation potential with electron affinity, a key energy term controlling electron intercalation, then with d-electron configuration, is investigated. Firstly, we find that the change of the intercalation potential with respect to the transition metal cations within the same structure class is correlated in an approximately mirror relationship with the electron affinity, based on first-principles calculations on three typical categories of cathode compounds including layered oxides and polyoxyanions Then, by using a new model Hamiltonian based on the crystal-field theory, we reveal that the evolution is governed by the combination of the crystal-field splitting and the on-site d-d exchange interactions.

Micro-contact printing of graphene oxide nanosheets for fabricating patterned polymer brushes.

A robust strategy is developed to fabricate micro-patterned graphene oxide (GO) films on a hydroxylated surface via micro-contact printing induced supramolecular self-assembly. Existing photoactive sites on the surface of GO allow further amplification by growing polymer brushes via self-initiated photografting and photopolymerization (SIPGP).

Controlled evaporative self-assembly of poly(acrylic acid) in a confined geometry for fabricating patterned polymer brushes.

A simple yet robust approach was exploited to fabricate large-scaled patterned polymer brushes by combining controlled evaporative self-assembly (CESA) in a confined geometry and self-initiated photografting and photopolymerization (SIPGP). Our method was carried out without any sophisticated instruments, free of lithography, overcoming current difficulties in fabricating polymer patterns by using complex instruments.

High-performance inverted solar cells based on blend films of ZnO Naoparticles and TiO(2) nanorods as a cathode buffer layer.

We reported the favorable cathode buffer layer based on a blend of ZnO nanoparticles (NPs) and TiO2 nanorods (NRs) applied to inverted solar cells. In addition to the high optical transmittance, the resultant blend film gave a relatively dense film with lower roughness than that of the respective single-component film. This improved the interface contact between the buffer layer and photoactive layer and therefore reduced the contact resistance and leakage current.

Low-voltage protonic/electronic hybrid indium zinc oxide synaptic transistors on paper substrates.

Low-voltage (1.5 V) indium zinc oxide (IZO)-based electric-double-layer (EDL) thin-film transistors (TFTs) gated by nanogranular proton conducting SiO2 electrolyte films are fabricated on paper substrates. Both enhancement-mode and depletion-mode operation are obtained by tuning the thickness of the IZO channel layer.

Manipulating surface ligands of copper sulfide nanocrystals: synthesis, characterization, and application to organic solar cells.

CuS NCs were synthesized via a facile sol-gel method without post-thermal treatment. The as-prepared CuS NCs were analyzed and confirmed by XRD, HR-TEM, EDS and XPS as hexagonal covellite CuS. The average diameter of the samples was about 3nm with narrow size distribution.

Substrate biasing effect on the physical properties of reactive RF-magnetron-sputtered aluminum oxide dielectric films on ITO glasses.

High dielectric constant (high-k) Al2O3 thin films were prepared on ITO glasses by reactive RF-magnetron sputtering at room temperature. The effect of substrate bias on the subband structural, morphological, electrode/Al2O3 interfacial and electrical properties of the Al2O3 films is systematically investigated. An optical method based on spectroscopic ellipsometry measurement and modeling is adopted to probe the subband electronic structure, which facilitates us to vividly understand the band-tail and deep-level (4.

NO oxidation catalysis on copper doped hexagonal phase LaCoO3: a combined experimental and theoretical study.

Cobalt-based perovskite catalysts showed excellent performance towards NO-NO2 oxidation. We systematically investigated the influence of different levels of Cu-doping on the catalytic performance of hexagonal phase LaCoO3 (LaCo1-xCuxO3 (x = 0.1, 0.

Multifunctional antireflection coatings based on novel hollow silica-silica nanocomposites.

Antireflection (AR) coatings that exhibit multifunctional characteristics, including high transparency, robust resistance to moisture, high hardness, and antifogging properties, were developed based on hollow silica-silica nanocomposites. These novel nanocomposite coatings with a closed-pore structure, consisting of hollow silica nanospheres (HSNs) infiltrated with an acid-catalyzed silica sol (ACSS), were fabricated using a low-cost sol-gel dip-coating method. The refractive index of the nanocomposite coatings was tailored by controlling the amount of ACSS infiltrated into the HSNs during synthesis.

Highly efficient organic photovoltaics via incorporation of solution-processed cesium stearate as the cathode interfacial layer.

Highly efficient organic solar cells were successfully demonstrated by incorporating a solution-processed cesium stearate between the photoactive layer and metal cathode as a novel cathode interfacial layer. The analysis of surface potential change indicated the existence of an interfacial dipole between the photoactive layer and metal electrode, which was responsible for the power conversion efficiency (PCE) enhancement of devices. The significant improvement in the device performance and the simple preparation method by solution processing suggested a promising and practical pathway to improve the efficiency of the organic solar cells.