Effect Of Polyetheramine Adsorption On The Colloid Behavior Of Montmorillonite Aqueous Dispersion

Clay mineral is the general name of hydrated phyllosilicates. Its crystal structure consists of layers made up of two tetrahedrally coordinated silicon atoms fused to an edge-shared octahedral sheet of either aluminum or magnesium hydroxide, which leads to their properties that it can swell and disperse easily when encountering water. In order to avoid the instability of shale while drilling, various kinds of non-aqueous drilling fluids are explored. However, such kinds of drilling fluids have many disadvantages such as:high cost, being hazardous to environment, etc. With the awareness of environmental protection and the development of legislation, much attention has been paid to high performance water based drilling fluids. Recently, one kind of polyamine which can be used as a superior inhibitor in drilling fluids has attracted much attention.This thesis is mainly focused on the interaction between poly(oxypropylene)diamine and montmorillonite, and the effect of such polyamine on the colloid behavior of montmorillonite dispersion, with the characterization methods of colloid chemistry. At the last part of the thesis, we proposed the inhibition mechanism of the polyamine.The main content of the thesis includes the following parts:i) Purify the montmorillonite sample with sedimentation method and characterize the sample with X-ray diffraction and X-ray fluorescence spectrometric. Furthermore, some basic physicochemical parameters such as:cationic exchange capacity (CEC), the distribution of diameter, zeta potential, etc. were also characterized.ii) The adsorption of poly(oxypropylene)diamine on montmorillonite was measured with the depletion method using the total organic carbon analyzer instrument. Additionally, experiment about the effect of electrolyte on the adsorption isotherm was also conducted.iii) The effect of poly(oxypropylene)diamine on the colloid behavior of montmorillonite dispersion was studied. Two systems, one with non-prehydrated montmorillonite, the other with prehydrated montmorillonite dispersion, were compared in our experiment. Characterization techniques including X-ray diffraction, transmission electron microscopy, rheology, etc. were used in the research.iv) The inhibition mechanism of poly(oxypropylene)diamine was postulated in the final part of the thesis based on the former experiment results.