Papers by Keyword: Adsorption Behaviour

Abstract: Cement asphalt mortar (CA mortar) is a highly flowable grouting material used in the slab track structure. Temperature significantly influences the workable time of CA mortar. The workable time of CA mortar is controlled by the adsorption of asphalt droplets in the emulsion on cement grains. In the present study, the absorption behaviours under different temperatures were investigated to reveal the influences of temperature on workable properties of CA mortar. A laser particle size analyzer was employed to characterize the particle size variation in the cement and asphalt emulsion (CAE) system. The results indicated that the particle size increased more prominently at elevated temperature; The viscosity of the CAE system was measured by a rotational viscometer, results indicated that variation pattern of viscosity correlated well with that of the particle size in the CAE system and the increase of particle size was partially accountable for the increase of viscosity and impairing the flowability of CA mortar; the workable properties of CA mortar were also investigated, results showed that the slump flow increased and the workable time decreased with the increase of temperature. The addition of non-ionic emulsifier could retard the adsorption behaviour between cement and asphalt and prolong the workable time of CA mortar.

Abstract: The modification of sodium trititanate whisker surface was performed by means of impregnation procedure to fabricate the modified sodium trititanate whisker, which was characterized by infrared spectroscopy(IR). Its adsorptive performance for Co(II) in a static system was investigated by FAAS. The main factors affecting adsorption and desorption of Co(II), the adsorptive capacity of Co(II) in optimal condition and adsorption isotherm. The adsorptive rate for Co(II) on 0.2500 g of modified sodium trititanate whisker at PH 6.0 was the best. Co(II) adsorbed on the modified sodium tretitanate whisker could be eluted with 10 mL of 3.0 mol/L HCl. The adsorptive performance of modified sodium trititanate whisker was better than that of unmodified sodium trititanate whisker.

Abstract: Using esterification-polymerization two-steps synthesis method, two kinds of comb-like polycarboxylate agents of BT and JS were synthesized by controlling acid-ester ratio. The adsorption characteristics of Ca²⁺ ions on comb-like polycarboxylate polymers in the CaCl₂ solution were studied. The results indicated that the adsorption behavior was closely related to the structure of polymers, the adsorption power of JS with water-reducing structure was strong, while weak with slump loss resisting polymers BT. The adsorption behavior was also in connection with the acid-ester ratio of polymer structure, the higher the acid-ester ratio is, the greater the absorption power; On the contrary, it will be smaller.

Abstract: In order to understand the adsorption property of wettability reversal surfactant, the adsorption rule of the wettability reversal surfactant on hydrophilic surface and lipophilic surface was studied, and the adsorption behavior of the wettability reversal surfactant on hydrophilic surface and lipophilic surface was studied by Atomic Force Microscope (AFM). The results show that there is a saturated adsorption capacity of all the wettability reversal surfactants on sandstone surface, and the adsorption quantity on lipophilic surface is bigger than that on hydrophilic surface. The AFM study show that the wettability reversal surfactant tends to distribute where is close to the oil droplet. Consequently, the wettability reversal surfactant is favorable for using in lipophilic surface.

Abstract: Based on good cation exchange property of vermiculite，the adsorption of vermiculite for simulated radionuclide Sr was studied by the static adsorption method. The adsorption behaviors and the effect of the experimental conditions were investigated. The results show that the saturated adsorption capacity of vermiculite sample for the simulated radionuclide Sr was 8.246×10-2 mmol/g. The suitable pH value ranged from 4 to 11, the balanceable adsorption time was 3d, and the suitable temperature was 30°C. The main adsorption type was cation exchange. The adsorption mechanism can be described by Langmuir and Freundlich models. It acts better in accord with Langmuir model, and the correlation coefficient is 0.99974. This experimental study has important significance on low concentration of Sr radioactive waste liquid treatment.

Abstract: Fibrinogen and albumin are two of the most important plasma proteins that relate to blood coagulation caused by engineered surfaces. In this paper, the adsorption behavior of albumin and fibrinogen on single-walled carbon nanotubes nonwoven (SWNT nonwoven) was investigated through scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), near edge X-ray adsorption fine structure spectroscopy (NEXAFS) and direct enzyme-linked immunosorbent assay (ELISA) respectively. It was concluded that SWNT nonwoven displayed strong adsorption preference of fibrinogen to albumin. In addition, the immune activity of fibrinogen adhered to the SWNT nonwoven surface was found remained and showed a linear response to the concentration in a certain range.