Novel urea-formaldehyde resin/reactive kaolinite composites containing 20-40wt%; kaolinite were prepared by in situ polymerization. The kaolinite was modified with tetraethoxysilane and a silane coupling agent to intr...
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Novel urea-formaldehyde resin/reactive kaolinite composites containing 20-40wt%; kaolinite were prepared by in situ polymerization. The kaolinite was modified with tetraethoxysilane and a silane coupling agent to introduce reactive groups. Fourier-transform infrared spectroscopy and X-ray diffraction confirmed preparation of the urea-formaldehyde resin/reactive kaolinite composites. The composite morphology was investigated using scanning electron microscopy; the composites consisted of uni- form spherical particles. The surface chemical components of the composites were determined using energy-dispersive X-ray spectroscopy. The spectra showed that the reactive kaolinite was encapsulated by the urea-formaldehyde resin. The thermal properties of the composites were examined using dif- ferential scanning calorimetry and thermogravimetric analysis. The results showed that their thermal stability was much better than that of pure urea-formaldehyde resin, Reactive kaolinite addition greatly decreased formaldehyde emissions and improved the water resistance of the composites. A mechanism for urea-formaldehyde resin/reactive kaolinite composite synthesis is proposed.
Two-phase cryogenic flow are involved in many cooling systems. In order to study the mechanism of cryogenic two phase flow. Two-phase pressure drop of liquid nitrogen (LN2) in a circular horizontal channels was experi...
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Recently,plasma-assisted combustion has become a potentially applicable technology in many combustion *** this paper,a dielectric barrier discharge（DBD） plasma generator is designed to explore the effect of plasma o...
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Recently,plasma-assisted combustion has become a potentially applicable technology in many combustion *** this paper,a dielectric barrier discharge（DBD） plasma generator is designed to explore the effect of plasma on the CH4 oxidation process,and several properties of combustion are ***,in the presence or absence of plasma discharge,physical appearance of the flame is examined and ***,the flame propagation velocity is calculated by the flame front extracted from the imaging data with the Bunsen burner ***,the main molecular components and their intensity variation in the flame and the plasma zones are identified with an emission spectrograph to analyze the effect of active species on the combustion *** also discuss the possible kinetic regime of plasma-assisted *** results imply that plasma discharge applied to the premixed CH_4/O_2/He mixture significantly raises the flame speed with equivalence ratios ranging from 0.85 to 1.10,with the flame speed improved by 17%to 35%.It can be seen that plasma can improve methane oxidation efficiency in the premixed fuel/oxidizer,especially at a low equivalence ratio.
To understand droplet motion on solid surfaces is very important for many applications such as enhanced oil recovery (Freitas et al.2011), droplet spreading, manipulation and fabrication of droplets in microfluidic de...
To understand droplet motion on solid surfaces is very important for many applications such as enhanced oil recovery (Freitas et al.2011), droplet spreading, manipulation and fabrication of droplets in microfluidic devices (Worner et al.2012).Solid surface wettability affects significantly the movement of the contact line and hence dominants the motion of droplets on solid surfaces, especially when the flow is confined to microscale.
Ions at the oil-water interface is a ubiquitous phenomenon which plays a important role in many industrial processes, such as extraction separation, nanoparticle assembly, enhanced oil recovery, *** the petroleum indu...
Ions at the oil-water interface is a ubiquitous phenomenon which plays a important role in many industrial processes, such as extraction separation, nanoparticle assembly, enhanced oil recovery, *** the petroleum industry, due to the long-term interaction with solids and crude oil, the water including formation water, injection water and aqueous solution dissolves lots of ions, such as Na+, K+, Ca2+, Mg2+, Cl-, SO42-, *** migration of charged ions in the bulk phase or interface between oil and water has a significant influence on the molecudar packing of active species at the interface, zeta potential of oil droplets and microstructure and strength of interfacial film by changing the interfacial tension, interface viscosity and electrical repulsion of charged ganglia, thus affecting the stability of crude oil emulsions and the oil displacement in porous ***, more detailed knowledge of how ions affect the properties of oil-water interface is required.
When a thin tube is dipped into water, the water will ascend to a certain height, against the action of gravity. While this effect, termed capillarity, is well known, recent experiments have shown that agitated granul...
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When a thin tube is dipped into water, the water will ascend to a certain height, against the action of gravity. While this effect, termed capillarity, is well known, recent experiments have shown that agitated granular matter reveals a similar behavior. Namely, when a vertical tube is inserted into a container filled with granular material and is then set into vertical vibration, the particles rise up along the tube. In the present Letter, we investigate the effect of granular capillarity by means of numerical simulations and show that the effect is caused by convection of the granular material in the container. Moreover, we identify two regimes of behavior for the capillary height Hc∞ depending on the tube-to-particle-diameter ratio, D/d. For large D/d, a scaling of Hc∞ with the inverse of the tube diameter, which is reminiscent of liquids, is observed. However, when D/d decreases down to values smaller than a few particle sizes, a uniquely granular behavior is observed where Hc∞ increases linearly with the tube diameter.
PMMA/reactive nanoclay nanocomposites were prepared by emulsion polymerization using two different reactive nanoclays. X-ray diffraction（XRD） and thermogravimetric analysis（TGA） results confirmed that the reactive...
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PMMA/reactive nanoclay nanocomposites were prepared by emulsion polymerization using two different reactive nanoclays. X-ray diffraction（XRD） and thermogravimetric analysis（TGA） results confirmed that the reactive nanoclays, kaolinite and montmorillonite, were obtained by the silylation reaction and the double bonds were grafted onto the edges and surfaces of the nanoclays. The presence of reactive nanoclays could increase the average molecular weights, the glass transition temperatures（Tg） and improve the thermal properties of nanocomposite. The tensile properties, Young＇s modulus, and the aging properties of the nanocomposite films were also enhanced while the light transmittance decreased. Furthermore, the nanocomposites with the reactive kaolinite presented better performances than that with the reactive montmorillonite. Finally, the action mechanism of the reactive nanoclays to the performances of PMMA/reactive nanoclay nanocomposites was proposed.
In this paper, the condensate droplets growth of Marangoni condensation during the time-series process was experimentally studied. The photographs taken in the experiments were handled by image processing method. The ...
In this paper, the condensate droplets growth of Marangoni condensation during the time-series process was experimentally studied. The photographs taken in the experiments were handled by image processing method. The droplets coverage ratio was introduced to analyse the growth process. As the time-series process went on, the condensate droplets coverage ratio increased fast at first, and then increased slowly until reaching a stable state. The droplets coverage ratio increased with the increase in the vapor-to-surface temperature difference and decreased with the increase in the ethanol vapor concentration.
The study puts forward a forced way to realize phase isolation by using a static cyclone device and provides a basis for a systematic study of the phase-isolation phenomenon for an oil-water two-phase flow in a vertic...
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