Toluene Sensing Properties of P4VP/Multi-Walled Carbon Nanotubes Multi-Layer Film Sensors

Abstract--Poly4-vinylphenol （P4VP）/multi-wan carbon nanotubes （MWNTs） multi-layer sensitive films were deposited on interdigitated electrodes by airbrush technology to detect toluene vapor at room temperature. The surface and section morphologies of the multi-layer films were observed by a scanning electron microscope （SEM）. It is found that the resistance of the sensor increases when it is exposed to toluene vapor and the response has a good linearity with the concentration of toluene. The results show that the P4VP/MWNTs three-layer film sensors have better sensing properties compared with the two-layer film sensors. The related sensing mechanism is studied in detail.

Electrodeposition of multi-layer Pd-Ni coatings on 316L stainless steel and their corrosion resistance in hot sulfuric acid solution

Pd-Ni coating shows good corrosion resistance in strong corrosion environments.However,in complex aggressiveenvironments,the performance of the coatings is limited and further improvement is necessary.The effects of the applied platingcurrent density on the composition,structure and properties of Pd-Ni coatings were studied.By changing the current density in thesame bath,multi-layer Pd-Ni coatings were prepared on316L stainless steel.Scanning electronic microscopy,weight loss tests,adhesion strength,porosity and electrochemical methods were used to study the corrosion resistance of the films prepared bydifferent coating methods.Compared with the single layer Pd-Ni coating,the multi-layer coatings showed higher microhardness,lower internal stress,lower porosity and higher adhesive strength.The multi-layer Pd-Ni coating showed obviously better corrosionresistance in hot sulfuric acid solution containing Cl-.

Observation of Magnetic Domain Structures of Magnetic Thin Films by the Lorentz Electron Microscopy

The microstructure change in thin NiFe/Cu/NiFe films during the magnetization process was observed by the Lorentz electronmicroscopy. TWo types of films were prepared: (1) one NiFe layer with anisotropy and the other layer without, and (2) both NiFe layershave anisotropy normal each other. The domain wall migration and magnetization rotation processes in each of NiFe layers could be observed separately. The presence of magnetic anisotropy in the magnetic layer effectively controls the behavior of magnetic domains. Theinteraction between the two NiFe layers of the film could be observed not so strong in the present experiment.

Hydrogen storage properties of preferentially orientated Mg-Ni multilayer film prepared by magnetron sputtering

Mg-Ni multi-layer thin film was deposited on (001) Si wafer by magnetron sputtering with dual-target. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis reveal that the microstructure of the Mg-Ni multilayer thin film is composed of fine-crystalline Ni layer and crystalline [001] Mg layer. Hydrogenation process of the films were carried out by using the automatic gas reaction controller. The films undergone hydrogenation for different time were analyzed by XRD. The results show that hydrogenation properties of Mg with different preferential orientations are different. (002) diffraction peak of Mg disappears in compensating the appearing of the peaks of Mg2NiH4 and MgH2 in hydrogenation at 533 K, while the (101) peak still remains. The result reveals that the Mg film with (001) preferential orientation absorbs hydrogen at certain temperature easier than that of the Mg film with (101) orientation. This phenomenon can be explained in the view point of the energy change for the nucleation and growth of hydride in different crystal plane.

Microwave Magnetic Properties of Laminates with Thin FeCoBSi Films

The microwave permeability of laminated composites based on thin FeCoBSi films was under study.The level of permeability increased with increasing of the ferromagnetic inclusions in the laminates.The intrinsic permeability spectra of ferromagnetic inclusion are parametrically reconstructed.The obtained parameters of magnetic resonance were specially analyzed.To avoid the effect of eddy current and to obtain large-volume fractions of ferromagnetic constituent,laminates consisting of alternating FeCoBSi/SiO2 multi-layers and mylar substrates were also investigated.For the same volume fractions of ferromagnetic constituent （8.7%）,laminates based on multi-layered films are found to possess higher values of permeability than those based on one-layered films.

Highly sensitive wearable sensor based on a flexible multi-layer graphene film antenna

The use of advanced carbon nanomaterials for flexible antenna sensors has attracted great attention due to their outstanding electromechanical properties. However, carbon nanomaterial based composites have yet to overcome drawbacks, such as low conductivity and toughness. In this work, a flexible multi-layer graphene film(FGF) with a high conductivity of 10~6 S/m for antenna based wearable sensors is investigated. A 1.63 GHz FGF antenna sensor exhibits significantly high strain sensitivity of 9.8 for compressive bending and 9.36 for tensile bending, which is super than the copper antenna sensor(5.39 for compressive bending and 4.05 for tensile bending). Moreover, the FGF antenna sensor shows very good mechanical flexibility, reversible deformability and structure stability, and thus is well suited for applications like wearable devices and wireless strain sensing.

Thermally conductive MWCNTs/Fe_(3)O_(4)/Ti_(3)C_(2)T_(x) MXene multi-layer films for broadband electromagnetic interference shielding

The Ti_(3)C_(2)T_(x)MXene is thought to be a promising candidate for next-generation electromagnetic interference(EMI) shielding materials.However,its broadband shielding capability and thermal conduction performance are insufficient to meet the growing demands.Herein,we reported a layer-by-layer composite film composed of Ti_(3)C_(2)T_(x)MXene,multi-walled carbon nanotubes(MWCNTs),and Fe_(3)O_(4)nanoparticles.Benefitting from the architecture and the synergistic effect of components,the obtained composite film exhibited high comprehensive performance.Specifically,the introduction of Fe_(3)O_(4)magnetic nanoparticles effectively reduced the impedance mismatch between the composite film and air and enhanced the magnetic loss of the composite film.The layered structure prolonged the transmission path of electromagnetic waves inside the composite film and constructed a rich conductive network,causing interfacial polarization and ohmic loss.The results indicated that the composite film(52 μm) delivered a high EMI shielding effectiveness of 49 dB in the frequency range from X-band to Ku-band.Furthermore,the MWCNTs layers in the composite films provided numerous heat transfer channels,reducing phonon scattering during heat transfer and resulting in a maximum thermal conductivity of 8.241 W/(m K).

FMR of Multi-layered Magnetic Film LaYIG/GGG/LaYIG/GGG

1 Introduction Since single crystal magnetic films which have multiple layers with the same magnetization such as LaYIG/GGG/LaYIG film were first made by the authors, they have been widely used in microwave delay line with linear dispersion and other devices. Recently ferromagnetic resonance （FMR） and magnetostatic wave propagation characteristics of similar multi-layered film have been studied by many authors, whichris important for the multi-layered film to be used in microwave region. But until now many important characteristics of the multi-layered film have not been well understood. The direction and magnitude of uniaxial anisotropy effective field H11, the widening of FMR linewidth △H,

Study of Optical Specifications of HfO₂/Y₂O₃, Sc₂O₃+ MgO, and Ta₂O₅+ TiO₂Used as Resonator Reflector for Nd:YAG Laser (1064 nm)

A theoretical design of a multi-layer for Nd:YAG mirrors resonator is described in this work. An output coupler was designed and fabricated by successive thin layers to achieve very high transmittance at optical wavelengths around 1064 nm for Nd:YAG mirrors resonator. The different film optical filters were used to control the transmittance and reflectance. The three samples of dielectric materials composed of HfO2/Y2O3, Sc2O3 + MgO, and Ta2O5 + TiO2 were used and compared with each other in transmittance, reflectance, full width at half maximum (FWHM), physical thickness, optical thickness, geometric thickness, and incident angles by the software [1].

Development of high-flux reverse osmosis membranes with MIL-101(Cr)/Fe3O4 interlayer

MIL-101(Cr)has a special pore cage structure that provides broad channels for the transport of water molecules in the reverse osmosis(RO)water separation and purification.Combining MIL-101(Cr)with FeO4 nanoparticles forms a water transport intermediate layer between the polyamide separation membrane and the polysulfone support base under an external magnetic field.MiL-101(Cr)is stable in both water and air while resistant to high temperature.With the introduction of 0.003 wt.%MIL-101(Cr)/Fe3O4,the water flux increased by 93.31%to 6.65 L.m-2.h-1.bar-1 without sacrificing the NaCl rejection of 95.88%.The MIL-101(Cr)/Fe3O4 multilayer membrane also demonstrated certain anti-pollution properties and excellent stability in a 72-h test.Therefore,the construction of a MIL-101(Cr)/FeO4 interlayer can effectively improve the permeability of RO composite membranes.