Papers by Keyword: Viscosity

Abstract: ·Copper conductive inks for screen printing are being given great attention due to their widely application in printed electronics industry. In this study, copper conductive ink used for screen printing, which were grinded by three-roll mill machine, was prepared using the epoxy, polyurethane and acrylic resins as adhesive, the flake copper particles which had a diameter between 20 to 50 μm as conductive material and butly alcohol was chosen as solvent. The viscosity and the thixotropy of the conductive ink were measured by rheometer. The oxidation of the surface layer of copper were removed by submerged in a certain concentration of acid solution and the resistance of the sample was measured after heated at different various temperatures. The results showed that the rheology were better for screen printing by adding the acrylic resin and the minimum conductivity can be reached 1.93×10^-3 Ω·cm.

Abstract: In the process of the ink drops forming and spreading out, the viscosity and surface tension of the ink play an important role, and then the drops’ injection and printing quality will be influenced by this process. Besides, drops control technology is the key of ink-jet printing technology, and the drops’ injection state will also influence the printing quality. In order to research the influencing factors to printing quality, many samples with different performances are prepared and their drop states include speed, tail length and volume are measured with drop observatory. And then, the specimen pages include lines of different width are printed, order to assessment the printing quality comprehensively, their line width, raggedness, blurriness, density and contrast are measured. The result show that the inks with different performance show different speed, tail length and volume, and their corresponding printing qualities are different too, and there exists linear relationship between printing quality and the drops’ viscosity, surface tension and speed.

Abstract: The amidation grafted copolymers derived from styrene-maleic anhydride copolymer were prepared and characterized by FTIR. Their intrinsic viscosity and crystal morphology were measured. The prepared polymers were investigated as pour point depressants (PPD) and flow improvers for waxy crude oil, and it was found that the depression effect of PPD modified by mixture amines was more effective than single amine, and the maximum depression was obtained by the sample that modified by mixture amines from 13 °C to 4 °C (ΔPP = 9 °C, at 3 000 ppm). The effect of the PPD modified by mixture amines on the flow properties of waxy crude oil was investigated. The result show that the viscosity decreased from 1 223 mPa.s to 81.3 mPa.s at 13 °C and 3 000 ppm. In addition, the crystal morphology have also been improved for the same sample and conditions.

Abstract: Synergistic effect of xylanase and bleaching agent on bleaching properties of KP pulp was investigated. The combination of ClO2 chlorination, alkali extraction and ClO2 bleaching with xylanase was applied. Results showed that X/DED bleaching process could make full use of xylanase, xylan was degraded and the role of bleaching agent was accelerated which enhancing the chemical accessibility of xylanase. The coordination of the two parts improved bleaching effect significantly. But for DX/ED bleaching process, the brightness of bleached pulp treated with different xylanase treating time was very low or a little low, indicating the role of xylanase on pulp was very important for improving bleaching properties, and residual xylanase had little effect on improvement of alkaline extract. Effect of xylanase in ClO2 stage had little effect on bleaching effect of pulp, and brightness are near each other. When xylanase and ClO2 were added together, xylanase almost did not show its role in bleaching, and bleaching result was neat to that of DED process

Abstract: On bases of numerical simulation and theoretical analysis, two cases of media, water and slurry (a kind of pseudoplastic power-law fluids), were used in the same hydrocyclone under the same operating condition. The Compare results show that the effect of the medium viscosity on the radial-velocity profile is slight; on the other hand, the effect of the media viscosity on the tangential-velocity profiles is important. The increase of the media viscosity produces not only the increase of the viscous resistance but also the steep reducing of the peak value of tangential-velocity profiles, which means that the inward viscous force loading upon the particles are enforced, on the other hand , the outward centrifugal force loading on the particles reduces greatly. The increase of the media viscosity leads to the great decrease of the separation ability of a hydrocyclone.

Abstract: In order to improve the stabilities of A95-aluminum-silicon sols, the influences of various ultrasonic field, ultrasonic time and ultrasonic frequency on the property of aluminum-silicon sols were researched. The physical-chemical performances of sols, such as the sol viscosity, rheological properties and microstructure, and so on, were measured. The results show that the influence of sonochemical actions on the stability of the Al₂O₃-SiO₂ sol is remarkable. Standing wave fields accelerate the molecules agglomeration of the sol. In the diffusion wave fields, the stability of the sol increases with ultrasonic frequency enhances, but the stability first increases and then reduces with the extension of ultrasonic time. When ultrasonic frequency and ultrasonic time is 100 Hz and 60 minutes respectively, the stability of the Al₂O₃-SiO₂ sol is the best.

Abstract: Nanometer europium oxide-doped titania particles were synthesized and electro-rheological fluids (ERFs) were prepared by reactions of those particles and hydroxyl silicone oil. The characteristics of particles were studied by transmission electron microscope, energy spectrum analysis and X-ray diffraction. The results show that europium oxide solid dissolve in titania and deposit on surface of titania , titania crystal become irregular and even particle size increase. Dielectric constant of titania is 3.25 and doped titania is 5.5. Viscosities and shear stresses of ERFs increase with electrical field increasing and all have critical field (2KV/mm),their viscosities are 4500 pa.s and 6340 pa.s, respectively(E= 3.5kv/mm). Shear stress of titania ERF change into 200 Pa from 50 Pa and that of doped titania ERF change into 800 Pa from 100 Pa when electrical field increased into 3 kv/mm from 0v/mm. Grafting reaction between particle and hydroxyl silicone oil improve stability ratio from 44% to 80 after 144 h.

Abstract: Abstract. Take the lauric acid, the ethylene diamine, the chloroacetic acid, the soda ash as raw material synthesized a new type of Anionic Gemini surfactants-N, N'-double lauroyl ethylene diamine two sodium acetate, The properties of the product were characterized, and the physical and chemical properties were determined. The experimental results can be seen that the anionic Gemini surfactants can greatly reduce the oil/water interface tension, and it has good viscosity properties, Thus deduced that the Gemini surfactants is better than the ordinary surfactant better table (world) surface activity, Can be used in the tertiary oil recovery field.

Abstract: In order to modify the rheological properties of epoxy resin adhesive in casting moulding technology and improve its bonding quality, the effects of thixotropic agents of hydrophilic nano-silica, organic bentonite and the composite agent of the two thixotropic ones on the rheological properties of epoxy resin (E-44) were studied by the evaluation parameters of viscosity and thixotropic index in this paper. The variation regulation of rheological properties of epoxy resin (E-44) with different thixotropic agents as the storage time was also investigated. The results show that the two thixotropic agents play a significant role in thickening the density and modifying the thixotropy of the epoxy resin (E-44). Especially, the thickening and thixotropic effects of the composite agent of 3phr hydrophilic nano-silica with 6phr organic bentonite are the most remarkable and the storage stability is also excellent.

Abstract: To obtain advance hetero-modulus and hetero-viscous complex materials with extreme high dynamic strength, wear and thermal shock resistances a novel approach was applied by the authors. The developed new hetero-modulus and hetero-viscous composites were reinforced with nanoparticles and submicron fibers and whiskers of Si₂ON₂, SiAlON, AlN, Si₃N₄ as well as with special additives, which had turned into amorphous phases during sintering. These types of materials have several Youngs modulus and viscosities simultaneously and have high damage tolerance and ability to absorb and dissipate the elastic energy during crack propagation. Understanding the energy engorgement of high speed collision processes, the material structures and rheological properties of such a complex hetero-modulus and hetero-viscous material the authors could mathematically describe the mechanical shear stresses in these complex materials. Analytical methods applied in this research were scanning electron microscopy (SEM), X-ray diffraction, and energy dispersive spectrometry, digital image analysis was applied to microscopy results, to enhance the results of transformations.