An interfacial polarization model for activated electrorheological suspensions

Surfactant influences the ER response in two different ways. At low surfactant concentrations, it enhances the ER response by enhancing the particle polarizability. While at large concentrations, the response degrades due to the non-linear conductivity in the continuous phase. The yield stress is proportional to the electric field strength squared at small surfactant concentrations, but increases more slowly with field strength at large concentrations. In this paper, an interfacial polarization model is introduced to predict the ER behavior of surfactant-activated ER suspensions. Maxwell-Wagner model was modified by incorporating the effects of surfactant adsorption and field-induced alteration of the surfactant structure. The modified interfacial polarization model predicts well the qualitative behavior of the surfactant activated ER suspensions over all surfactant concentration ranges.     

Recent Theoretical Results for Nonequilibrium Deposition of Submicron Particles

Selected theoretical developments in modeling of deposition of sub-micrometer size (submicron) particles on solid surfaces, with and without surface diffusion, of interest in colloid, polymer, and certain biological systems, are surveyed. We review deposition processes involving extended objects, with jamming and its interplay with in-surface diffusion yielding interesting dynamics of approach to the large-time state. Mean-field and low-density approximation schemes can be used in many instances for short and intermediate times, in large enough dimensions, and for particle sizes larger than few lattice units. Random sequential adsorption models are appropriate for higher particle densities (larger times). Added diffusion allows formation of denser deposits and leads to power-law large-time behavior which, in one dimension (linear substrate, such as DNA), was related to diffusion-limited reactions, while in two dimensions (planar substrate), was associated with evolution of the domain-wall and defect network, reminiscent of equilibrium ordering processes.     

齐鲁分公司SBS改性沥青的生产

中石化齐鲁分公司胜利炼油厂20t/hSBS改性沥青装置由三维石化化工设计院设计，建设公司施工，通过在基质沥青中加入SBS改性沥青母粒及化学助剂经胶体磨剪切，SBS以一定粒度的颗粒均匀分散在基质沥青中，以达到改善和提高沥青流变性及感温性能的目的。     

Adsorbing colloidal flotation removing metals ions in a modified jet cell

The removal of Cu²⁺, Zn²⁺ and Ni²⁺ ions from synthetic wastewater with a modified Jameson cell (MJC) was studied using adsorption colloidal flotation (ACF). A colloidal dispersion of Fe (OH)₃ (formed in situ from FeCl₃) at pH 11 was used as an adsorbent colloid to ensure full adsorption and precipitation. The precipitates were flocculated with polyacrylamide and hydrophobised with sodium oleate and pine oil as a frother during the flotation stage. In the modified jet cell, the downcomer was sealed at the bottom with a diffuser, and the re-flotation of detached flocs and the probability of bubbles/particles capture was enhanced, which improved the recovery rate. As a result, the modified Jameson cell was more efficient (higher loaded carrier recoveries) than the conventional jet cell (CJC) in removing heavy metals ions. The physico-chemical characteristics, cell design and operating parameters were studied, and the removal efficiency was evaluated by monitoring the final concentration of ions in the treated effluent. The results indicated that the removal efficiencies of the MJC were approximately 95% and 98% for dilute (Cu²⁺, Zn²⁺ and Ni²⁺ concentration of 2 mg/L) and concentrated wastewater (25 mg/L of each ion), respectively. The optimal parameters included a Fe⁺³/ion ratio of 0.5 and a minimum air flow-rate/feed flow-rate ratio of 0.18. The results are discussed in terms of the physical and physico-chemical parameters, and the findings suggested that the proposed flotation technique has great potential for the treatment of wastewater.     

Estimation of colloidal deposition from heterogeneous populations

This paper reports a study of size-heterogeneous colloid filtration in a new bed using different types of colloids under different conditions of flow and solution chemistry. Depth-wise variation of the particle-size-distributions f_i(x), and the total liquid-phase colloid concentration, C(x) are measured which are used to estimate the depth-wise variation of the liquid-phase concentration for each distinct section of the heterogeneous population, C_i(x). It is observed that log C_i(x) is linear with depth, for some systems, while it shows deviation from linearity, with the slope decreasing with depth, for others. Deposition-rates for these distinct sections of the heterogeneous population, k_i, are estimated from the slopes of the log C_i(x) data. These deposition-rates were then compared with predicted homogeneous-population deposition-rates from Colloid Filtration Theory (CFT), which shows agreement between the CFT-based-deposition-rates and heterogeneous-population-data based deposition-rates, for low flow velocities. At higher flow velocities a gap between the CFT-based and Data-based deposition-rates is observed. Deposition-rates from CFT are then used in a heterogeneous-colloid-filtration model, to examine if heterogeneous colloid deposition can be expressed as the sum of its parts. It is observed that, the sum-of-parts model provides a reasonable estimate of colloidal deposition from heterogeneous populations. Based on these results, it is possible to make predictions of colloidal deposition from complex heterogeneous suspensions. A new method for studying heterogeneous colloid filtration is also proposed.     

Effect of aluminium sulphate on interactions between silica surfaces studied by atomic force microscopy

Surface interaction forces between different types of silica surfaces (pure silica beads, borosilicate glass beads, polished silicon wafers and fused silica slides) were measured by atomic force microscopy (AFM) in solutions of aluminium sulphate (alum) in order to understand the role of hydrated aluminium species on the coagulation of negatively charged oxide colloids in drinking water treatment. The alum coagulant concentration used in this study was 150 microM aluminium. The alum solutions were prepared from analytical grade Al2(SO4)3.16H2O. It was found that the presence of aluminium sulphate at a concentration close to the values typically used in industrial scale water treatment applications generally induced strong, long-range repulsive forces between the various types of surfaces studied. At this alum concentration streaming potential measurements indicated reversal in the sign of the surface charge. It was also found that whenever borosilicate glass beads were used, the interaction force became strongly attractive when the AFM cell was flushed with deionised water. It was argued that this attraction occurred because of the charge nonuniformity of the aluminium hydrates adsorbed at the glass surface. A mechanism was proposed to explain the observed interaction phenomena based on the deduced microstructure of the adsorbed surface layers and to rationalise the new findings for applications in drinking water treatment.     

塑钢门窗专用中空密封剂的研制

塑钢门窗专用中空密封剂是以聚硫橡胶为基料的两组分密封剂，由胶体和固化剂两部分组成。文中主要考察了中空密封剂胶体的制备时间，制备温度，也考察了聚硫橡胶的质量百分含量对胶体性能的影响，在常温常压下考察了固化剂用量，密封剂的耐水性，耐化学试剂性，最后确定了中空密封剂胶体的最佳制备条件。     

Composite colloids and patterning

Over the past decade, the synthesis and application of various composite colloids and their ordered patterning have received considerable attention. We summarize the recent progress in morphology and composition control of various spherical, non-spherical composite colloids and their patterning. Hollow colloids, ellipsoidal colloids and their patterning are highlighted for their unique properties as well as broad applications.     

乳化炸药生产中螺杆泵和胶体磨的使用安全性

讨论了螺杆泵和胶体磨在乳化炸药生产中的使用安全性 ,提出了生产中应注意的问题及工艺、设备的改进措施和建议 ,对乳化炸药的安全生产有一定的指导意义     

ANALYSIS OF DIFFUSE PARENCHYMAL LIVER DISEASE BY LIVER SCINTIGRAMS: DIFFERENTIAL DIAGNOSIS USING FUZZY INFERENCE AND GENETIC ALGORITHM IN NUCLEAR MEDICINE

In nuclear medicine, diagnosis of diffuse parenchymal liver disease such as chronic hepatitis (CH) or liver cirrhosis (LC) is evaluated by size and distortion of the liver, distribution of radioactive tracer in the liver, size and activities of the tracer in the spleen, the degree of visualization of the bone marrow, etc. using colloid liver scintigraphy, It is not difficult to read a scintigram for a typical pattern; however in some cases it is difficult to distinguish between normal and CH or CH and LC visually. Therefore, we tried to use fuzzy inferences to perform differential diagnosis. Using fuzzy inference, differential diagnosis of LC could be performed up to 100%, but those of CH and Severe fibrosis (SF) could not be performed sufficiently. Therefore genetic algorithm was tried to determine the fuzzy rules. By combining genetic algorithm and fuzzy inference, CH, SF, and LC could be differentiated to the degree 70%, 60%, and 100%, respectively.