Fabrication of UV-Curing Linalool-Polysiloxane Hybrid Films with High Refractive Index and Transparency

In this article,a series of high refractive indices(1.50-1.53)thiol phenyl polysiloxane(TPS)were synthesized via hydrolytic sol-gel reaction.The Fourier transform infrared spectra(FT-IR)and nuclear magnetic resonance spectra(NMR)results showed that TPS conformed to the predicted structures.Natural terpene linalool was exploited as photocrosslinker to fabricate UV-curing linalool-polysiloxane hybrid films(LPH)with TPS via photoinitiated thiol-ene reaction.LPH rapidly cured under UV irradiation at the intensity of 80 mW/cm^(2) in 30 s,exhibiting good UV-curing properties.The optical transmittance of LPH in the wavelength of 300-800 nm was over 90%,exhibiting good optical transparency.The water contact angle and water vapor permeability results showed that the introduction of phenyl groups enhance the hydrophobicity and water vapor barrier properties of LPH.The results indicated the potential of LPHs in the applications of optical functional coatings.

Degradation of Pollutant and Antibacterial Activity of Waterborne Polyurethane/Doped TiO_2 Nanoparticle Hybrid Films

The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne polyurethane, followed by heat treatment. The presence and nanometric distribution of doped Ti O2 nanoparticles in prepared membranes is evident according to SEM images. The photocatalytic activities of doped Ti O2 were signifi cantly enhanced compared with pure Ti O2 powders. After the hybrid fi lm fabrication, the photocatalytic activities were almost the same as the pure catalysts with kMB of 0.046. In the antibacterial testing, the hybrid fi lms can inhibit E. coli growth. A signifi cant decrease in membrane fl uidity and increase of permeability of E. coli were observed.

PREPARATION OF POLYIMIDE-BaTiO3 HYBRID FILMS BY A DISPERSION PROCESS AND THEIR MICROSTRUCTURE

Barium titanate (BaTiO3) powders with particle sizes of 30 similar to 50 nm were prepared from barium stearate, titanium alkoxides and stearic acid by stearic acid-gel method. Dispersing the agglomerate of BaTiO3 nanoparticles into poly(amic acid) solution followed by curing led to the formation of polyimide hybrid films. The hybrid films were transparent and well distributed with BaTiO3 nanoparticles when the BaTiO3 content was less than 1 wt%. Highly loaded hybrid film containing 30 wit % BaTiO3 was tough, had a smooth surface and possessed much higher dielectric and piezoelectric constants than the parent polyimide.

Transparent and conductive PEDOT:PSS/Ag NW/PEDOT:PSS hybrid films prepared by spin-coating at room temperature

PEDOT：PSS/Ag NW/PEDOT：PSS hybrid films were deposited on PET substrates by the spin coating technique at room temperature. The optical transmittance, sheet resistance, crystallization and surface morphology were characterized by using the double beam spectrophotometer, Hall effect system, X-ray diffractometer and field emission scanning electron microscopy. XRD patterns of the hybrid films display characteristic diffraction peaks of Ag （111） and Ag （200）, and the Ag NW networks have a polycrystalline structure with a Ag （111） preferred orientation. A high transmittance of 83.95% at the 550 nm wavelength and a low sheet resistance of 21.98 Ω/□ are achieved for 3-PEDOT：PS S/5-Ag NW/3-PEDOT： PS S hybrid films.

A Simple Approach to the Fabrication of Graphene-Carbon Nanotube Hybrid Films on Copper Substrate by Chemical Vapor Deposition

In this study,graphene-carbon nanotube（CNT） hybrid films were directly synthesized on polycrystalline copper（Cu） substrates by thermal chemical vapor deposition（CVD） method.Graphene films were synthesized on Cu substrate at 1000 ℃ in mixture of gases:argon（Ar）,hydrogen（H2）,and methane（CH4）.Then,carbon nanotubes（CNTs） were grown uniformly on the surface of graphene/Cu films at 750 ℃ in mixture of Ar,H2.and acetylene（C2H2） gases.Ferric salt FeCl3solution deposited onto the surface of graphene/Cu substrate by spin coating method was used as precursor for the growth of the CNTs.The density and quality of the CNTs on the surface of graphene/Cu films can be controlled by varying the concentration of FeCl3salt catalyst.

Sol-gel-derived Hybrid Conductive Films for Electromagnetic Interference (EMI) Shielding

The conductive nano-sized zinc particles were embedded in an insulating amorphous silica matrix,and the hybrid films were obtained by a sol-gel method.The stable hybrid sol solution was prepared by hydrolysis and condensation of Methyltrimethoxysilane （MTMS） with a one-step acidic catalyst process.Hybrid films were dip-coated on silicon wafer and cured at 120℃ for 60minutes.The structural characterization of hybrid films were investigated by means of attenuated total reflection infrared （ATR-IR） spectroscopy and X-ray diffraction （XRD）.The electrical properties of the films were examined with four-point probe.Hybrid films showed to be relatively dense,uniform and defect free.The conductivity of hybrid films was varied with the different contents of zinc nanoparticles and the thickness of the film.It was observed that there was the percolation threshold for the film＇s electrical properties.

Construction of all-organic low dielectric polyimide hybrids via synergistic effect between covalent organic framework and cross-linking structure

Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of allorganic PI hybrid films were successfully prepared by introducing the covalent organic framework(COF),which could induce the formation of the cross-linking structure in the PI matrix.Due to the synergistic effects of the COF fillers and the cross-linking structure,the PI/COF hybrid film containing 2 wt%COF exhibited the lowest dielectric constant of 2.72 and the lowest dielectric loss(tanδ)of 0.0077 at 1 MHz.It is attributed to the intrinsic low dielectric constant of COF and a large number of mesopores within the PI.Besides,the cross-linking network of PI prevents the molecular chains from stacking and improves the fraction of free volume(FFV).The molecular dynamics simulation results are well consistent with the dielectric properties data.Furthermore,the PI/COF hybrid film with 5 wt%COF showed a significant enhancement in breakdown strength,which increased to 412.8 kV/mm as compared with pure PI.In addition,the PI/COF hybrid film achieve to reduce the dielectric constant and thermal expansion coefficient(CTE).It also exhibited excellent thermal,hydrophobicity,and mechanical performance.The all-organic PI/COF hybrid films have great commercial potential as next-generation electronic packaging materials.

Hybrid Luminescent Films Obtained by Covalent Anchoring Terbium Complex to Silica-based Network

New monomer N-(4-carboxyphenyl)-NL-(propyltriethoxysilyl)urea (1) which acts as both a ligand for Tb3+ ion and a sol-gel precursor has been synthesized and characterized by 1H NMR, and MS. Hybrid luminescent thin films consisting of organoterbium covalently bonded to a silica-based network have been obtained in situ via a sol-gel approach. Strong line emission of Tb3+ ion was observed from the hybrid luminescent films under UV excitation.

Deterioration Process of the Hybrid Films during Wear Test--Polyacrylate Emulsion Modified by Silica Particles

The hybrid materials are widely used in various fields for excellent performance. However, there are few researches studying their failure process. In order to prepare the hybrid materials with better performance, the failure process needs to be well studied. Two kinds of silica/polyacrylate films are successfully prepared to study the effect of organic-inorganic interaction on performance. The average diameter of silica particles is measured to be around 342 nm by scanning electron microscope（SEM）. Wear test demonstrates the hybrid film, which is obtained by grafting polyacrylate onto silica particles, possesses more excellent properties than the one filled directly with silica particles. The stronger interaction between organic and inorganic components leads to a better distribution of inorganic particles within the polymer matrix. In this work, a model is presented to illustrate the deterioration process of the hybrid films, which allows us to further understand the hybrid materials.

Preparation and Characterization of Ternary Europium ComplexDoped Thin SolGel Hybrid Film by Fluorescence Spectroscopy

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Monte Carlo simulations of biaxial structure in thin hybrid nematic film based upon spatially anisotropic pair potential

Hybrid nematic films have been studied by Monte Carlo simulations using a lattice spin model, in which the pair potential is spatially anisotropic and dependent on elastic constants of liquid crystals. We confirm in the thin hybrid nematic film the existence of a biaxially nonbent structure and the structure transition from the biaxial to the bent-director structure, which is similar to the result obtained using the Lebwoh-Lasher model. However, the step-like director＇s profile, characteristic for the biaxial structure, is spatially asymmetric in the film because the pair potential leads to K1 ≠ K3. We estimate the upper cell thickness to be 69 spin layers, in which the biaxial structure can be found.

Intercalating Ultrathin MoO_3 Nanobelts into MXene Film with Ultrahigh Volumetric Capacitance and Excellent Deformation for High-Energy-Density Devices

The restacking hindrance of MXene films restricts their development for high volumetric energy density of flexible supercapacitors toward applications in miniature,portable,wearable or implantable electronic devices.A valid solution is construction of rational heterojunction to achieve a synergistic property enhancement.The introduction of spacers such as graphene,CNTs,cellulose and the like demonstrates limited enhancement in rate capability.The combination of currently reported pseudocapacitive materials and MXene tends to express the potential capacitance of pseudocapacitive materials rather than MXene,leading to low volumetric capacitance.Therefore,it is necessary to exploit more ideal candidate materials to couple with MXene for fully expressing both potentials.Herein,for the first time,high electrochemically active materials of ultrathin MoO3 nanobelts are intercalated into MXene films.In the composites,MoO3 nanobelts not only act as pillaring components to prevent restacking of MXene nanosheets for fully expressing the MXene pseudocapacitance in acidic environment but also provide considerable pseudocapacitive contribution.As a result,the optimal M/MoO3 electrode not only achieves a breakthrough in volumetric capacitance(1817 F cm-3 and 545 F g-1),but also maintains good rate capability and excellent flexibility.Moreover,the corresponding symmetric supercapacitor likewise shows a remarkable energy density of 44.6 Wh L-1(13.4 Wh kg-1),rendering the flexible electrode a promising candidate for application in high-energy-density energy storage devices.

Encapsulation of metal layers within metal-organic frameworks as hybrid thin films for selective catalysis

A facile encapsulation strategy for the preparation of metal layer/metal-organic framework （metal/MOF） hybrid thin films, by alternately growing MOF thin films and sputter-coating metal layers, is reported. The controlled species of the MOF thin films and metal layers, as well as the designed thickness of MOF thin films, endow the resulting hybrid thin films with improved functional and design flexibility. Importantly, the metaL/MOF hybrid thin films, with well-defined sandwich structures, exhibit excellent selective catalytic activity, derived from MOFs acting as molecular sieves and the metal layers providing active sites.

Preparation and characterization of polyimide/silica/silver composite films

Polyimide/silica/silver hybrid films were prepared by the sol-gel method combined with in situ singlestage self-metallization technique.The structure of polyimide films in the thermal curing process and the influence of silica content on the migration and aggregation of silver particles to the surface of hybrid films were investigated.The hybrid films were characterized by transmission electron microscopy,dynamic mechanical thermal analysis,Fourier transform infrared spectroscopy,ultraviolet visible spectroscopy and mechanical measurements.The results indicated that there was no degradation of the polyimide matrix after the formation of silica and silver particles.Silica acted as the nucleus for the silver particles.With increasing silica content,more and more silver particles were kept in the hybrid films instead of beingmigrated onto the surface of the hybrid films and the reflections of hybrid films decreased gradually.

Preparation and Visible-light Photochromism of Phosphomolybdic Acid/Polyvinylpyrrolidone Hybrid Film

The visible-light photochromic hybrid film was constructed by entrapping phosphomolybdic acid（PMoA） into polyvinylpyrrolidone（PVPd） networks. The microstructure, photochromic properties and mechanism were inves- tigated with transmission electron microscopy（TEM）, atomic force microscopy（AFM）, Fourier transform infrared （FTIR） spectroscopy, ultraviolet-visible（UV-Vis） spectra and X-ray photoelectron spectroscopy（XPS）. The results in- dicate that the Keggin geometry of PMoA and the basic structure of PVPd are not destroyed during the composite process. Irradiated with visible light, the transparent PMoA/PVPd film changes color from colorless to blue and ex- hibits reversible photochromism in the presence of oxygen. According to the XPS analysis, the charge-transfer bridge of N-H-O has been built between PMoA and PVPd matrix via non-covalent bonding, and the appearance of Mo5＋ species indicates that the photo-reduction process is in accordance with the proton transfer mechanism.

Fabrication and characterization of microfibrillated cellulose and collagen composite films

Microfibrillated cellulose(MFC)-collagen composite films were prepared with a dispersion of acid swollen collagen fibers and carboxylated MFC at different ratios in an alkaline homogenous system.The surface topographic results obtained from SEM analyses indicated that the MFC entangled uniformly with collagen in the film and formed a closely interwoven network to reinforce the film structure.However,the MFC addition decreased the smoothness and light transparency of the films due to the aggregation of MFC.Compared to the film prepared with pure collagen,the hybrid composite film showed a higher strength and Young’s modulus but lower elongation.The swelling of the composite film in water increased with the increase of the MFC ratio in the film matrix.DSC and TG analyses demonstrated that adding MFC to collagen benefited the thermal stability of the films,due to the conformational and crystal changes in the MFC/collagen structure indicated by the FT-IR and XRD results.The MFC/collagen composite film can potentially be used as an edible material in the food and packaging industry,in particular for meat products.

Photopatternable PEDOT:PSS/PEG hybrid thin film with moisture stability and sensitivity

Degradation and delamination resulting from environmental humidity have been technically challenging for poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)thin-film processing.To overcome this problem,we introduced a one-step photolithographic method to both pattern and link a PEDOT:PSS film onto a poly(ethylene glycol)(PEG)layer as a hybrid thin film structure on a flexible substrate.This film exhibited excellent long-term moisture stability(more than 10 days)and lithographic resolution(as low as 2μm).Mechanical characterizations were performed,including both stretching and bending tests,which illustrated the strong adhesion present between the PEDOT:PSS and PEG layers as well as between the hybrid thin film and substrate.Moreover,the hybrid moisture-absorbable film showed a quick response of its permittivity to environmental humidity variations,in which the patterned PEDOT:PSS layer served as an electrode and the PEG layer as a moisture-sensing element.Perspiration tracking over various parts of the body surface as well as breath rate measurement under the nose were successfully carried out as demonstrations,which illustrated the potential utility of this stable hybrid thin film for emerging flexible and wearable electronic applications.

Bismuth oxide nanoflake@carbon film: A free-standing battery-type electrode for aqueous sodium ion hybrid supercapacitors

Aqueous hybrid supercapacitors are promising due to their low cost and high safety. Herein, a freestanding battery-type electrode of Bi2O3 nanoflake@C on carbon cloth is designed for aqueous sodium ion hybrid supercapacitors. Due to the integration of nanoarray architecture and the conductive carbon,the Bi2O3@C electrode exhibits a high specific capacity of 207 mAh/g at 2 A/g（6C）, good rate capability and cycling stability（133 m Ah/g after 1000 cycles）. With the activated carbon as the capacitive electrode and neutral sodium salts as the electrolyte, a 1.9 V hybrid supercapacitor is assembled,delivering a high energy density of 18.94 Wh/kg. The device can still maintain 72.3% of initial capacity after 650 cycles. The present work holds great promise for developing next-generation hybrid supercapacitors.

Hybridized electronic states between CdSe nanoparticles and conjugated organic ligands： A theoretical and ultrafast photo-excited carrier dynamics study

Formation of densely packed thin films of semiconductor nanocrystals is advantageous for the exploitation of their unique optoelectronic properties for real-world applications. Here we investigate the fundamental role of the structure of the bridging ligand on the optoelectronic properties of the resulting hybrid film. In particular, we considered hybrid films formed using the same CdSe nanocrystals and two organic ligands that have the same bidentate dithiocarbamate bInding moiety, but differ in their bridging structures, one bridged by ethylene, the other by phenylene that exhibits conjugation. Based on the results of photo- excited carrier dynamics experiments combined with theoretical calculations on the electronic states of bridged CdSe layers, we show that only the phenylene- based ligand presents a strong hybridization of the molecular HOMO state with CdSe layers, that is a marker of formation of an effective bridge. We argue that this hybridization spread favors the hopping of photo-excited carriers between nanocrystals, which may explain the reported larger photo-currents in phenylene-based hybrid films than those observed in ethylene-based ones.