scholarly journals Changes on the Surface of the SiO2/C Composite, Leading to the Formation of Conductive Carbon Structures with Complex Nature of DC Conductivity

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2158
Author(s):  
Piotr Okoczuk ◽  
Marcin Łapiński ◽  
Tadeusz Miruszewski ◽  
Piotr Kupracz ◽  
Leszek Wicikowski
Keyword(s):  
Sol Gel ◽  
Composite Films ◽  
Positive Temperature Coefficient ◽  
Complex Nature ◽  
Positive Temperature ◽  
Total Electrical Conductivity ◽  
Carbon Structures ◽  
Coating Method ◽  
The Subject

Sol–gel layers have been the subject of many studies in recent decades. However, very little information exists about layers in which carbon structures are developed in situ. Using the spin-coating method, we obtained thin iron-doped SiO2/C composite films. The results of Raman spectroscopy showed that our samples consisted of graphitic forms and polymers. The latter’s contribution decreases with rising temperature. FTIR and EDS studies show changes in carbon distribution on top of the layer, depending on the sintering temperature. The samples sintered at 800 °C showed a significant increase in the contribution of carbon forms to the layer’s surface. Therefore, high conductivity can be observed in this sample. The results of XPS spectroscopy showed that the contribution of sp3 hybridized carbon increases after etching. The total electrical conductivity, studied by a DC four-wire technique, increased with the temperature and showed almost linear characteristics with significant changes below 150 K. The reduced activation energy plot has a positive temperature coefficient, which is a characteristic property of the conductive polymers in a metallic regime of conductivity.

scholarly journals Optical Isomerization and Photo-Patternable Properties of GeO2/Ormosils Organic-Inorganic Composite Films Doped with Azobenzene

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 818
Author(s):  
Xuehua Zhang ◽  
Qian Wang ◽  
Shun Liu ◽  
Wei Zhang ◽  
Fangren Hu ◽  
...  
Keyword(s):  
Optical Waveguide ◽  
Data Storage ◽  
Optical Switching ◽  
Sol Gel ◽  
Composite Films ◽  
Optical Data Storage ◽  
Optical Data ◽  
Single Chip ◽  
Coating Method ◽  
Inorganic Composite

GeO2/organically modified silane (ormosils) organic-inorganic composite films containing azobenzene were prepared by combining sol-gel technology and spin coating method. Optical waveguide properties including the refractive index and thickness of the composite films were characterized by using a prism coupling instrument. Surface morphology and photochemical properties of the composite films were investigated by atomic force microscope and Fourier transform infrared spectrometer. Results indicate that the composite films have smooth and neat surface, and excellent optical waveguide performance. Photo-isomerization properties of the composite films were studied by using a UV–Vis spectrophotometer. Optical switching performance of the composite films was also studied under the alternating exposure of 365 nm ultraviolet light and 410 nm visible light. Finally, strip waveguides and microlens arrays were built in the composite films through a UV soft imprint technique. Based on the above results, we believe that the prepared composite films are promising candidates for micro-nano optics and photonic applications, which would allow directly integrating the optical data storage and optical switching devices onto a single chip.

scholarly journals Sol-Gel Synthesis of TiO2/SiO2 and ZnO/SiO2 Composite Films and Evaluation of Their Photocatalytic Activity towards Methyl Green

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. L. Chandraboss ◽  
B. Karthikeyan ◽  
J. Kamalakkannan ◽  
S. Prabha ◽  
S. Senthilvelan
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Methyl Green ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Coating Method ◽  
Dip Coating Method

The TiO2/SiO2 and ZnO/SiO2 composite films were prepared by sol-gel dip coating method. The surface morphology and crystal structure of thin films were characterized by means of scanning electron microscopy (SEM) with elementary dispersive X-ray analysis (EDX) and X-ray diffractometer (XRD). Optical properties of films have been investigated using ultraviolet and visible spectroscopy (UV-visible spectroscopy). The photocatalytic activity was established by testing the degradation and decolorization of methyl green (MG) from aqueous solution with artificial UV-light.

Preparation and Photoelectric Properties of Nb/SnO2 Composite Thin Films

2016 ◽  
Vol 852 ◽  
pp. 1118-1122
Author(s):  
Rui Ying He ◽  
Chang Ping Wei ◽  
Guo Dong Wang ◽  
Jing San
Keyword(s):  
Sol Gel ◽  
Composite Films ◽  
Ultraviolet Region ◽  
Doping Amount ◽  
Experimental Conditions ◽  
Glass Substrates ◽  
Structure And Morphology ◽  
Near Ultraviolet ◽  
Photoelectric Properties ◽  
Coating Method

By using sol-gel method, Nb/SnO2 gel was prepared,and spin coating method was used to coat on glass substrates, which dried and calcined to obtain a homogeneous Nb / SnO2 composite films.Under the same experimental conditions, the different doping amount of nickel, calcination temperature on the structure and morphology of Nb/SnO2 film were discussed. By using XRD, IR, SEM and other testing methods, the structure and morphology of Nb / SnO2 composite film were characterized.At 500 °C, the film particle had high crystallization and small size,and the surface of the film was well-distributed.Its optical and electrical properties were tested by the ultraviolet-visible spectrophotometer and four-probe resistivity meter.UV-Vis spectra showed that Nb / SnO2 film absorbance in the near ultraviolet region had increased significantly, but the absorbance showed a downward trend with the increasing amount of Nb5+ doped;Conductivity analysis showed: Nb5+ doping amount of 8% (the amount of material), the conductivity of Nb/SnO2 composite films was best.

In‐situ sol–gel synthesis of zirconia networks in flexible and conductive composite films

2020 ◽  
Vol 137 (46) ◽  
pp. 49506
Author(s):  
Mohammad Hossein Azarian ◽  
Wan Ahmad Kamil Mahmood
Keyword(s):  
Sol Gel ◽  
Composite Films ◽  
Conductive Composite ◽  
Sol Gel Synthesis

scholarly journals Resistivity-Temperature Behavior of Intrinsically Conducting Bis(3-methoxysalicylideniminato)nickel Polymer

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2925
Author(s):  
Evgenii Beletskii ◽  
Valentin Ershov ◽  
Stepan Danilov ◽  
Daniil Lukyanov ◽  
Elena Alekseeva ◽  
...  
Keyword(s):  
Conductive Polymer ◽  
Lithium Ion ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Electrically Conductive ◽  
Resistivity Measurements ◽  
Elemental Analyses ◽  
Li Ion ◽  
Conductive State

Materials with a positive temperature coefficient have many applications, including overcharge and over-temperature protection in lithium-ion (Li-ion) batteries. The thermoresistive properties of an electrically conductive polymer, based on a Ni(salen)-type backbone, known as polyNiMeOSalen, were evaluated by means of in situ resistivity measurements. It was found that the polymer was conductive at temperatures below 220 °C; however, the polymer increased in resistivity by three orders of magnitude upon reaching 250 °C. Thermogravimetric results combined with elemental analyses revealed that the switch from the insulation stage to the conductive stage resulted from thermally dedoping the polymer. Electrochemical studies demonstrated that a polymer retains its electroactivity when it is heated and can be recovered to a conductive state through oxidation via electrochemical doping in an electrolyte solution.

Near Infrared Cut-Off Characteristics of Various Perovskite-Based Composite Films

2012 ◽  
Vol 229-231 ◽  
pp. 2733-2736 ◽  
Author(s):  
Jae Young Kim ◽  
Seung Yong Jeong ◽  
Gyo Jic Shin ◽  
Sang Kug Lee ◽  
Kyung Ho Choi
Keyword(s):  
Near Infrared ◽  
Sol Gel ◽  
Composite Films ◽  
Wavelength Region ◽  
Nanocomposite Films ◽  
Solvothermal Reaction ◽  
Polyethylene Terephthalate Film ◽  
Coating Method ◽  
Cubic Structure ◽  
Pet Film

Homogenous cesium tungsten tri-oxide (CsxWO3) and molybdenum tri-oxide (Cs0.33MoO3) powder was prepared by solvothermal reaction using (NH4)10H2(W2O7)6, H8MoN2O4 and Cs2CO3 aqueous solution followed by annealing. The cesium doped tungsten tri-oxide (CsxWO3) and the cesium doped molybdenum tri-oxide (CsxMoO3) nanocomposite films was deposited by the sol-gel bar-coating method onto PET-film (polyethylene terephthalate film, thickness 186 ㎛) substrate. The structure and sizes of ceramic particles was observed XRD and PSA spectrometer, the optical properties of their films were investigated by UV-VIS, NIR spectrometer. Synthesized particles typically formed cubic structure for good absorption of NIR, size observed as being 30-100 nm and 3 nanoparticles showed a high transmittance in the visible wavelength region as well as excellent shielding capability of near-infrared (NIR) wavelength, indicating that CsxWO3, Cs0.33MoO3 nanoparticles have a appropriate characteristic as solar filter applications.

In-situ low-temperature sol-gel growth of nano-cerium oxide ternary composite films for ultraviolet blocking

2020 ◽  
Vol 101 ◽  
pp. 109724 ◽  
Author(s):  
Lulu Lu ◽  
Guolun Dai ◽  
Liuliu Yan ◽  
Lijin Wang ◽  
Lingnan Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cerium Oxide ◽  
Sol Gel ◽  
Composite Films ◽  
Gel Growth ◽  
Ternary Composite
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