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Xifeng Hou Yanhui Zheng Xiaolong Ma Yuheng Liu Zichuan Ma 《Molecules (Basel, Switzerland)》2021,26(4)
To expand the applications of graphene-based materials to biogas purification, a series of reduced graphene oxide aerogels (rGOAs) were prepared from industrial grade graphene oxide using a simple hydrothermal method. The influences of the hydrothermal preparation temperature on the textural properties, hydrophobicity and physisorption behavior of the rGOAs were investigated using a range of physical and spectroscopic techniques. The results showed that the rGOAs had a macro-porous three-dimensional network structure. Raising the hydrothermal treatment temperature reduced the number of oxygen-containing groups, whereas the specific surface area (SBET), micropore volume (Vmicro) and water contact angle values of the rGOAs all increased. The dynamic adsorption properties of the rGOAs towards hexamethyldisiloxane (L2) increased with increasing hydrothermal treatment temperature and the breakthrough adsorption capacity showed a significant linear association with SBET, Vmicro and contact angle. There was a significant negative association between the breakthrough time and inlet concentration of L2, and the relationship could be reliably predicted with a simple empirical formula. L2 adsorption also increased with decreasing bed temperature. Saturated rGOAs were readily regenerated by a brief heat-treatment at 100 °C. This study has demonstrated the potential of novel rGOA for applications using adsorbents to remove siloxanes from biogas. 相似文献
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We report on the formation of superhydrophobic surfaces on glass by plasma polymerization with non-polar aromatic hydrocarbon, at atmospheric pressure, in an in-line process. The glass was simply treated by radio frequency (RF) plasma with a mixture of toluene and hexamethyldisiloxane (HMDSO). The hydrophobicity of the sample surfaces increase with increasing plasma treatments; contact angles of 150° for water droplets are achieved. It is attributed mainly to its high content of non-polar hydrophobic phenyl groups and its rough surface. 相似文献
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Hexamethyldisiloxane (HMDS) was polymerized onto metallic and insulating substrates in a parallel-plate DC reactor. The limits
of the DC reactor with respect to pressure and power were determined for deposition of PP-HMDS films. In all conditions ranging
from 5 Pa/0.3 W to 100 Pa/50 W, solid films were deposited. No powders or oily films were obtained under any condition in
this operating range. The films were polymeric in nature,i.e., they were neither carbon-like nor SiO
x
-like films. The structures and crosslink densities of the plasma films dependend strongly on the deposition conditions. The
highest deposition rates, up to 2 μm per minute (or0.3 mg/cm2 min), were obtained at high power, pressure, and flow rate conditions. An efficiency ɛ is introduced, defined as the fraction
of the monomer that is retained in the form of a polymer deposited on the substrate. Efficiencies as high as 25% could be
obtained in certain conditions. Pulsing the discharge power increased the conversion efficiency markedly, but the effect depended
strongly on the monomer used. In addition to HMDS, plasma polymers were also deposited from pyrrole in pulsed conditions for
comparison. A method is described for depositing films on insulators from a DC glow discharge using two wire meshes held at
a negative potential. 相似文献
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Jose A. López‐Barrera Alejandro Avila‐Ortega Juan Morales Jorge Cervantes Roberto Olayo 《应用有机金属化学》2007,21(10):858-861
The surface of quarry stone was modified by continuous plasma polymerization of hexamethyldisiloxane. The hydrophilic surface of the quarry stone was made hydrophobic and impermeable to water. Three different reaction times were analyzed. All of them resulted in the formation of a homogenous layer on the quarry stone surface. Contact angle and FT‐IR analyses show that the hydrophobic character of the surface is due to methyl groups on the surface. The change in the contact angle with temperature and the wetting temperature (Tw) are also discussed. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Tunable Diode Laser Absorption Studies of Hydrocarbons in RF Plasmas Containing Hexamethyldisiloxane
Röpcke J. Revalde G. Osiac M. Li K. Meichsner J. 《Plasma Chemistry and Plasma Processing》2002,22(1):139-159
Tunable infrared diode laser absorption spectroscopy has been used to detect the methyl radical and three stable molecules, CH4, C2H2 and C2H6, in radio frequency plasmas (f=13.56 MHz) containing hexamethyldisiloxane (HMDSO). The methyl radical concentration and the concentration of the stable hydrocarbons, produced in the plasma, have been measured in pure HMDSO discharges and with admixtures of Ar, while discharge power (P=20–200 W), total gas pressure (p=0.08–0.6 mbar), gas mixture and total gas flow rate (=1–10 sccm) were varied. The methyl radical concentration was found to be in the range of 1013 molecules cm-3, while methane and ethane are the dominant hydrocarbons with concentrations of 1014–1015 mol cm-3. Conversion rates to the measured stable hydrocarbons (RC(CxHy): 2×1012–2×1016 molecules J-1 s-1) could be estimated in dependence on power, flow, mixture and pressure. Under the used experimental conditions a maximum deposition rate of polymer layers of about 400 nm min-1 has been found. 相似文献
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碱/酸两步催化法制备耐候性SiO2增透膜的研究 总被引:1,自引:1,他引:0
以正硅酸乙酯(TEOS)为先驱体,采用碱/酸两步催化溶胶-凝胶法制备出一种兼具碱催化增透膜的高透过率和酸催化增透膜的良好耐摩擦性能的优点的SiO2增透膜。对酸碱催化SiO2相对比例及酸催化时水含量的系统研究表明,当酸催化SiO2的含量为50%时,增透膜综合性能最好,即具有高透过率和高耐摩擦性;当nH2O/nHCl=1∶0.0010时,增透膜的透过率最高。碱/酸两步催化法制备的增透膜与水的接触角仅为11.3°,本文进一步用六甲基二硅氧烷(HMDS)对增透膜表面进行了修饰,修饰后增透膜的接触角提高至52.5°,增透膜的疏水性及环境稳定性得到较大的提高。 相似文献
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Saker Saloum Samer Abou Shaker M.Nidal Alkafri Asmhan Obaid Rokayya Hussin 《Surface and interface analysis : SIA》2019,51(7):754-762
Plasma-polymerized hexamethyldisiloxane (pp-HMDSO) thin films have been deposited in a radiofrequency (RF) remote plasma-enhanced chemical vapor deposition (PECVD) system, on different types of substrates: silicon wafers, glass, quartz crystals, and chemiresistor structure. The as-grown thin films have been post treated in two types of reactive plasmas produced in SF6 and O2 gases. The effect of this surface modification on different properties of the as-grown pp-HMDSO thin film (chemical structure, elemental composition, surface morphology, film density and thickness, optical bandgap, and electrical resistivity) has been investigated. It is found that SF6 plasma and O2 plasma surface modifications of the as-grown pp-HMDSO thin film induce property changes different from each other. SF6 plasma converted the as-grown pp-HMDSO film to a more porous material and caused a narrowing of its optical band gap of about 33%, while O2 plasma induced a lowering of film electrical resistivity of about two orders of magnitude. 相似文献
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Hexamethyldisiloxane (HMDSO) is one of the main impurities in the syngas produced from sewage and landfill plants. In order to utilize this syngas or control the characteristics of the generated silica particles, it is crucial to understand the chemical kinetics of HMDSO combustion. This study investigated the process of HMDSO combustion using synchrotron radiation mass spectrometry (SRMS), gas chromatography (GC), and ReaxFF molecular dynamics simulations. First, the force field used for ReaxFF simulation was validated by comparing the energies of different bond lengths, bond angles, and dihedral angles with the ones from DFT calculations. Good agreements were found. Then, ReaxFF simulations of HMDSO combustion with this force field were conducted under various conditions, which include different equivalence ratios (0.67, 1.0, and 1.5) and temperatures ranging from 2000 to 3500 K. The oxidation characteristics of HMDSO were analyzed, including the evolution of gas products and particle formation. Finally, based on the results from experiments and ReaxFF simulations, the reaction pathways, reaction lists, and reaction kinetics data during HMDSO combustion were obtained. A detailed reaction mechanism was proposed and validated by applying it in modeling the H2/HMDSO/O2 combustion systems. The temperature and part of the gas products such as CO and CO2 as well as SiO could be well predicted. 相似文献