Kaolinite Layers Research Articles

Combined experimental and theoretical investigation of interactions between kaolinite inner surface and intercalated dimethyl sulfoxide

Kaolinite intercalation complex with dimethyl sulfoxide (DMSO) was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry–differential scanning calorimetry (TG–DSC) combined with molecular dynamics simulation. The bands assigned to the OH stretching of inner surface of kaolinite were significantly perturbed after intercalation of DMSO into kaolinite. Additionally, the bands attributed to the vibration of gibbsite-like layers of kaolinite shifted to the lower wave number, indicating that the intercalated DMSO were strongly hydrogen bonded to the alumina octahedral surface of kaolinite. The slightly decreased intensity of 1031cm−1 and 1016cm−1 band due to the in-plane vibration of SiO of kaolinite revealed that some DMSO molecules formed weak hydrogen bonds with the silicon tetrahedral surface of kaolinite. Based on the TG result of kaolinite–DMSO intercalation complex, the formula of A12Si2O5(OH)4(DMSO)0.7 was obtained, with which the kaolinite–DMSO complex model was constructed. The molecular dynamics simulation of kaolinite–DMSO complex directly confirmed the monolayer structure of DMSO in interlayer space of kaolinite, where the DMSO arranged almost parallel with kaolinite basal surface with all methyl groups being distributed near the interlayer midplane and oxygen atoms orienting toward to the alumina octahedral surface. The radial distribution function between kaolinite and intercalated DMSO verified the strong hydrogen bonds forming between hydroxyl hydrogen atoms of alumina octahedral surface and oxygen atoms of DMSO. Moreover, some methyl groups of DMSO were weakly hydrogen bonded to the oxygen atoms of silicon tetrahedral surface through the hydrogen atoms. The mean square displacement of DMSO oxygen atoms and hydrogen atoms in z direction kept unchanged during the simulation time because of the hydrogen-bond interaction between inner surface of kaolinite and DMSO, which constrained the mobility of intercalated DMSO in the direction normal to the kaolinite basal surface.

New organophilic kaolin clays based on single-point grafted 3-aminopropyl dimethylethoxysilane.

In this study, the organophilization procedure of kaolin rocks with a monofunctional ethoxysilane- 3 aminopropyl dimethyl ethoxysilane (APMS) is depicted for the first time. The two-step organophilization procedure, including dimethyl sulfoxide intercalation and APMS grafting onto the inner hydroxyl surface of kaolinite (the mineral) layers was tested for three sources of kaolin rocks (KR, KC and KD) with various morphologies and kaolinite compositions. The load of APMS in the kaolinite interlayer space was higher than that of 3-aminopropyl triethoxysilane (APTS) due to the single-point grafting nature of the organophilization reaction. A higher long-distance order of kaolinite layers with low staking was obtained for the APMS, due to a more controllable organiphilization reaction. Last but not least, the solid state (29)Si-NMR tests confirmed the single-point grafting mechanism of APMS, corroborating monodentate fixation on the kaolinite hydroxyl facets, with no contribution to the bidentate or tridentate fixation as observed for APTS.

Back diffusion from thin low permeability zones.

Aquitards can serve as long-term contaminant sources to aquifers when contaminant mass diffuses from the aquitard following aquifer source mass depletion. This study describes analytical and experimental approaches to understand reactive and nonreactive solute transport in a thin aquitard bounded by an adjacent aquifer. A series of well-controlled laboratory experiments were conducted in a two-dimensional flow chamber to quantify solute diffusion from a high-permeability sand into and subsequently out of kaolinite clay layers of vertical thickness 15 mm, 20 mm, and 60 mm. One-dimensional analytical solutions were developed for diffusion in a finite aquitard with mass exchange with an adjacent aquifer using the method of images. The analytical solutions showed very good agreement with measured breakthrough curves and aquitard concentration distributions measured in situ by light reflection visualization. Solutes with low retardation accumulated more stored mass with greater penetration distance in the aquitard compared to high-retardation solutes. However, because the duration of aquitard mass release was much longer, high-retardation solutes have a greater long-term back diffusion risk. The error associated with applying a semi-infinite domain analytical solution to a finite diffusion domain increases as a function of the system relative diffusion length scale, suggesting that the solutions using image sources should be applied in cases with rapid solute diffusion and/or thin clay layers. The solutions presented here can be extended to multilayer aquifer/low-permeability systems to assess the significance of back diffusion from thin layers.

Theoretical Study of the Intercalation Behavior of Ethylene Glycol on Kaolinite

Different kinds of models of ethylene glycol (EG) intercalated on kaolinite are investigated by means of density functional theory (DFT). It is found that the most possible mode of EG intercalated on kaolinite is a mixing of physical intercalation and covalent grafting of EG. If the existence of water was considered, the possibility for EG intercalating on kaolinite is as follows: mixing of physical intercalation and covalent grafting > physical intercalation > covalent grafting. The distance between the carbon atom of the bonded EG and the Al atom of the kaolinite lamella are calculated to be about 3 Å, which is in good agreement with the experimental value. The methylene and hydroxyl groups of EG or grafting EG can form hydrogen bonds with both adjacent layers of kaolinite with d(001) of 9.40 Å. With the expanding of the d(001) value from 9.40 to 10.85 Å, the van der Waals forces become more important in the stabilization of EG molecule in the interlayer space.

Morphology and orientation of curling of kaolinite layer in hydrate

In order to determine if there are curlings along other directions than [100] and [010] in kaolinite (Kaol) layer, 1nm Kaol hydrate with 85% yield was synthesized by the fluorine-free method. Its structure and morphology were investigated by X-ray diffraction (XRD), field emission transmission electron microscopy (FETEM) and selected area electron diffraction (SAED). The results show that: (1) there are not only single curling and two opposite parallel curlings, but also two adjacent curlings with about 120° angle in one single layer; (2) there are four new orientations of curlings [11¯0], [110], [310] and [31¯0] in Kaol hydrate. The reasons that Kaol layers can curl along multiple directions may be that: first, two types of incompatible matchings between tetrahedrons and octahedrons; second, the hexagonal distribution and the zigzag distribution of two types of matchings.

Nanotubular Halloysite Clay as Efficient Water Filtration System for Removal of Cationic and Anionic Dyes

Halloysite nanotubes, chemically similar to kaolinite, are formed by rolling of kaolinite layers in tubes with diameter of 50 nm and length of ca. 1 μm. Halloysite has negative SiO2 outermost and positive Al2O3 inner lumen surface, which enables it to be used as potential absorbent for both cationic and anionic dyes due to the efficient bivalent adsorbancy. An adsorption study using cationic Rhodamine 6G and anionic Chrome azurol S has shown approximately two times better dye removal for halloysite as compared to kaolinite. Halloysite filters have been effectively regenerated up to 50 times by burning the adsorbed dyes. Overall removal efficiency of anionic Chrome azurol S exceeded 99.9% for 5th regeneration cycle of halloysite. Chrome azurol S adsorption capacity decreases with the increase of ionic strength, temperature and pH. For cationic Rhodamine 6G, higher ionic strength, temperature and initial solution concentration were favorable to enhanced adsorption with optimal pH 8. These results indicate a potential to utilize halloysite for the removal of ionic dyes from environmental waters.

Growth surface topography of kaolinite-group minerals and their simulation based on the regular sequence of enantiomorphic layers

The regularities of manifestation of polytypism in a number of kaolinite-group minerals (kaolinite, dickite, halloysite, and nacrite) have been investigated by transmission electron microscopy and vacuum decoration. Growth patterns of elementary layers with a thickness of 7 A, individual for each polytype, were observed on (001) faces of microcrystals. Specific features of the growth patterns of polytypes have been revealed by comparing them with simulated patterns constructed based on a packing of regularly alternating right- and left-handed (enantiomorphic) kaolinite layers. The new approach to the consideration of the polytypism of kaolinite minerals is substantiated by the absence of symmetry elements in the 7-A-thick layer, which determines their structure; the formation of enantiomorphic forms of kaolinite; the presence of grazing-reflection planes in the growth patterns; and the structure of polytypes with a two-layer period. Packing of enantiomorphic layers may yield eight structures, two of which correspond to the right- and left-handed forms of kaolinite, one is for dickite, two are for halloysite, and three are for nacrite. It is shown that the simulated and real growth patterns of these minerals are in good correspondence.

Formulation and characterization of compatibilized poly(lactic acid)-based blends and their nanocomposites with silver-loaded kaolinite

Biodegradable polymer nanocomposites have been developed in this study as materials for use in the packaging of moisture-sensitive products. Poly(lactic acid) (PLA) was the main component of the nanocomposites with poly(butylene adipate-co-terephthalate) (PBAT) as flexibility enhancer. Tetrabutyl titanate was also added as a compatibilizer to enhance the interfacial affinity between PLA and PBAT by inducing the formation of some PLA/PBAT via transesterification during the melt blending process, thereby improving the mechanical properties of the blends. Silver-loaded kaolinite synthesized via chemical reduction was also incorporated into the compatibilized blends for further property improvement. Herein, we report a novel biodegradable quaternary nanocomposite system with intercalated-exfoliated clay dispersion that was uniquely achieved by increasing the interlamellar space between kaolinite layers through silver nanoparticle insertion. The resultant nanocomposites containing as little as 4 phr modified clay reduced the elongation at break from 213.0 ± 5.85% to 53.8 ± 1.81%, enhanced thermal stability (initial decomposition temperature increased from 378 °C to 399 °C) and exhibited a water vapor permeability reduction of 41.85%. On the basis of these properties, the developed nanocomposites are considered to be promising candidates for use in bio-packaging applications to replace non-biodegradable and petro-based plastics. © 2014 Society of Chemical Industry

Pedogenic alteration of illite in subtropical China

AbstractPedogenic alteration of illite from red earth sediments in Jiujiang in subtropical China was investigated using X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Illite, hydroxy-interlayered vermiculite (HIV), kaolinite and mixed-layer illite-HIV (I-HIV) are present in the soils. The characteristic reflections of the clay phases were 14 Å, 10–14 Å, 10 Å, and 7 Å, respectively. After Mg-glycerol saturations, the 14 Å peak of the samples did not expand, and after heating at 350°C and 550°C it shifted to 13.8 Å and 12 Å respectively, with no residual 14 Å reflection, suggesting the occurrence of hydroxy-interlayered vermiculite. The randomly interstratified I-HIV clays were characterized by a broad peak at 10–14 Å, which did not change its position after Mg-glycerol saturation, but collapsed to 10 Å after heating at 350°C and 550°C. HRTEM analysis showed different lattice fringes of 12 Å, 10 Å and 7 Å . Mixed-layer I-HIV, HIV-K and illite-kaolinite (I-K) were observed in the HRTEM images which represented the intermediate phases during illite alteration. The merging of two 10 Å illite layers into a 12 Å HIV layer, lateral transformation of one HIV layer into one kaolinite layer and alteration of one illite layer into two kaolinite layers illustrated the mechanisms of illite-to-HIV, HIV-to-kaolinite and illite-tokaolinite transformation, respectively. The proposed pedogenic alteration of illite and the weathering sequence of the clay minerals in Jiujiang is illite → I-HIV → HIV → HIV-K → kaolinite. In addition, illite may transform directly to kaolinite.

Polyimide/kaolinite composite films: Synthesis and characterization of mechanical, thermal and waterproof properties

Polyimide (PI)/kaolinite composites were successfully synthesized via in situ polymerization using kaolinite–potassium acetate intercalation compound (KKAc) as the intermediate. XRD patterns, FTIR spectrum and SEM images revealed that polyimide have partially intercalated into the layers of kaolinite by replacing KAc molecules. The mechanical, thermal and optical properties of the composite films were characterized by universal tester, TGA, and UV–vis spectrometer. It was found that the introduction of modified kaolinite led to significant increase in tensile strength and elongation at break of PI matrix when KKAc content was no more than 5wt%. Electron microscopy characterization indicated that some plate-like and clusters-like structure appeared in perpendicular to the fracture surface of composite films after tensile tests other than in pure PI film, which meant stronger fracture resistance existing in the composite films. The introduction of modified kaolinite also resulted in improved thermal stability, slight decrease in transmittance and marked decrease in water uptake ratio at low clay content (≤5wt%). Therefore, the polyimide/kaolinite composites have potential application in microelectronic devices.

Preparation and properties of poly(2,3-dimethylaniline)/organic–kaolinite nanocomposites via in situ intercalative polymerization

Abstract Poly(2,3-dimethylaniline)/kaolinite nanocomposites (P(2,3-DMA)/K2) were prepared by in situ intercalative polymerization in the presence of organically modified kaolinite, based on the intercalation modification of crude kaolinite with dimethylsulfoxide (DMSO) and methanol system. Intercalation extent of kaolinite, Structure, Morphology and Thermal stability of the nanocomposites were characterized by XRD, FTIR, SEM and TGA–DTA, respectively. The electrochemical behavior of the as-prepared nanocomposites was evaluated by open circuit potential (OCP), tafel polarization curves (TAF) and impedance spectroscopy (EIS) in 3.5 wt% NaCl aqueous solution. Experimental results indicated that the clay layers of kaolinite in P(2,3-DMA)/K2 were well intercalated and exfoliated, and the P(2,3-DMA)/K2 had a more higher thermal stability and anticorrosion properties relative to the bulk poly(2,3-dimethylaniline) (P(2,3-DMA)) and the P(2,3-DMA)/crude kaolinite composites (P(2,3-DMA)/K0).

Intercalation of urea into kaolinite for preparation of controlled release fertilizer

In this study urea was intercalated between layers of kaolinite by dry grinding technique to be used for preparing controlled release fertilizer. X-ray powder diffraction (XRPD) patterns confirmed the intercalation of urea into kaolinite by the significant expansion of the basal spacing of kaolinite layers from 0.710 nm to 1.090 nm. Fourier transform infrared spectroscopy (FT-IR) also confirmed the hydrogen bonding between urea and kaolinite. Based on CHNS elemental analysis, 20% (wt.) urea was intercalated between kaolinite layers. The urea-intercalated kaolinite was mixed with hydroxypropyl methylcellulose (HPMC) binder and was granulated to prepare the nitrogen-based controlled release fertilizer. To study the nitrogen release behavior of granules, ultraviolet/visible (UV-Vis) spectroscopy was used through the diacetyl monoxime (DAM) colorimetric method. The result of UV-Vis spectroscopy showed that intercalation of urea into kaolinite decreased the nitrogen release from 25.50 to 13.66 % after 24 hours and from 98.15 to 70.01% after 30 days incubation in water. According to the results, the prepared controlled release fertilizer (CRF) behaved according to the standard for CRFs.

The positions of inner hydroxide groups and aluminium ions in exfoliated kaolinite as indicators of the external chemical environment.

Kaolinite as a remarkable industrial raw material has notable structural features despite its simple chemical composition (Al2O3·2SiO2·2H2O). We report here a systematic development of a coordination chemical model for the [6Al-6(OH)] honeycomb-like unit of kaolinite's octahedral sheet, which was proposed to be the adsorption site for small molecules from earlier studies. The coordination environment of the Al(3+) ions was completed with outer sphere groups from both octahedral and tetrahedral sheets. Dangling bonds were terminated by additional Al(3+) and Si(4+) ions with hydroxide and oxide groups from the second coordination sphere versus simple protonation. A cage of Na(+) and Mg(2+) ions rendered the computational model to be charge neutral. In this exfoliated kaolinite model, the inner hydroxide groups and the adjacent Al(3+) ions have compositionally the most complete environments with respect to the crystal structure. Thus, their atomic positions were used as a benchmark for the level of theory dependence of the optimized structures. We evaluated the performance of a representative set of density functionals, basis sets, point-charges, identified pitfalls and caveats. Importantly, the structural changes during optimization of periodic and cluster models suggest pliability for the exfoliated kaolinite layers, which is influenced by the external chemical environment.

SiO2-kaolinite affecting the surface properties of ternary poly(vinyl chloride)/silica/kaolinite nanocomposites

The products from the dispersion of nanoscale particulates such as the layered clays or the spherical inorganic minerals within the polymeric matrices are called polymeric nanocomposites. In this paper, we prepared poly(vinyl chloride) (PVC) based nanocomposites containing SiO2-kaolinite by melt compounding. The influence of SiO2-kaolinite on the surface properties of PVC was investigated by the use of various surface analysis techniques including a ttenuated total reflectance spectroscopy (ATR), wide angle X-ray diffractometry (WAXD), atomic force microscopy (AFM), scanning electron microscopy (SEM), electron dispersive X-ray spectrometer (EDX), contact angle measurement (CAM), and reflectance spectroscopy (RS). ATR spectroscopy showed possible interaction between layered kaolinite and PVC at surface. Microscopic methods illustrated an increased surface roughness compared to the pure PVC. Contact angle measurements of the resultant PVC nanocomposites demonstrated that the wettability of substrates depends on the surface interactions between kaolinite layers and PVC matrix. Optical properties of nanocomposite films were finally measured by the aid of reflectance spectrophotometer. It can be seen from optical studies that reflectance values were increased after incorporation of SiO2-kaolinite in nanocomposite.

From platy kaolinite to aluminosilicate nanoroll via one-step delamination of kaolinite: Effect of the temperature of intercalation

Aluminosilicate nanorolls were prepared using a method of one-step delamination of kaolinite. In this method, cetyltrimethylammonium chloride (CTMACl) was intercalated into the interlayer space of methoxy-modified kaolinite, which resulted in the delamination and rolling of kaolinite layers. The reaction conditions of CTMACl intercalation significantly influenced the formation of nanorolls, as shown by characterizations using X-ray diffraction, electron microscopy, infrared spectroscopy, thermal analysis, and nitrogen adsorption. Overall, increasing the CTMACl-intercalation temperature helps to promote the transformation from platy kaolinite to nanorolls. The initial kaolinite particles were mostly transformed to nanorolls in the product prepared at 80°C, whereas considerable kaolinite particles remained untransformed in the product prepared at 30°C. At 80°C, the obtained specific surface area (SSA) and the porous volume (Vpor) values of the nanoroll product are nearly twice the values obtained at 30°C and the tubular structure exhibits higher thermal persistence. The tubular morphology and the porosity of these nanorolls obtained at 80°C, were largely retained after calcination at 600–800°C. However, a calcination at 900°C led to an obvious distortion of the nanorolls and a decrease in SSA and Vpor values. The observed structural changes of the nanorolls under calcination generally resembled that of natural halloysite but occurred at lower temperatures because the prepared nanorolls were of lower structural order with thinner tube walls.

Theoretical study of interaction of formamide with kaolinite

The interactions between small molecules and clay minerals have attracted more interest of scientists recently due to the wide use of them in the catalysts and environmental absorbents. In the clays, kaolinite as an important layered aluminosilicate presents a variety of physicochemical properties. In this paper, the clusters of Si6O18H12, Al6O24H30 and Si6Al6O42H42 were constructed for tetrahedral, octahedral layers and isolated kaolinite to investigate the microscopic properties of formamide (FA) on kaolinite layers by Density Function Theory (DFT) methods. All computations were performed at the B3LYP (Becke, three-parameter, Lee–Yang–Parr exchange–correlation functional) level using the 6-31G(d) basis set. The properties, such as the optimal structures, structural parameters, interaction energies, NBO (natural bond orbital) charge distributions, vibrational frequencies, electrostatic potential, were extracted from them. The results show that hydrogen bonds between FA and the surface hydroxyl groups of the octahedral layer or the basal oxygen atoms of the tetrahedral layer in kaolinite are formed. The absolute values of calculated interaction energies on the tetrahedral layer are smaller than those on the octahedral layer and the interaction energies of adsorbed systems are smaller than intercalated one, which indicate that the adsorption between FA and octahedral layer of kaolinite is stronger than that of FA on the tetrahedral layer of kaolinite, and the intercalation is more stable than the adsorption.

Structure of kaolinite and influence of stacking faults: Reconciling theory and experiment using inelastic neutron scattering analysis

The structure of kaolinite at the atomic level, including the effect of stacking faults, is investigated using inelastic neutron scattering (INS) spectroscopy and density functional theory (DFT) calculations. The vibrational dynamics of the standard crystal structure of kaolinite, calculated using DFT (VASP) with normal mode analysis, gives good agreement with the experimental INS data except for distinct discrepancies, especially for the low frequency modes (200-400 cm(-1)). By generating several types of stacking faults (shifts in the a,b plane for one kaolinite layer relative to the adjacent layer), it is seen that these low frequency modes are affected, specifically through the emergence of longer hydrogen bonds (O-H⋯O) in one of the models corresponding to a stacking fault of -0.3151a - 0.3151b. The small residual disagreement between observed and calculated INS is assigned to quantum effects (which are not taken into account in the DFT calculations), in the form of translational tunneling of the proton in the hydrogen bonds, which lead to a softening of the low frequency modes. DFT-based molecular dynamics simulations show that anharmonicity does not play an important role in the structural dynamics of kaolinite.

Structure of prismatic halloysite

The crystal structure of halloysite, despite being one of the most commonly occurring clay minerals on the Earth’s surface, remains elusive. This paper reports on a multi-methodological study to shed more light on the atomic arrangement of halloysite from Olkhon Island, Lake Baikal, Russia, which has a prismatic morphology. It has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), selected-area electron diffraction (SAED) and, in particular, high-resolution transmission electron microscopy (HRTEM), to reveal its atomic structure and formation process. XRD analysis indicated a basal spacing of ca. 7.2 A and two characteristic peaks with d = 4.28 and 4.03 A on the tail of the 02,11 band. The halloysite grain cross sections displayed various prismatic forms, ranging from a rectangle to a regular 18-sectored polygon in SEM and TEM. The SAED pattern from a sector of the polygonal prisms with the incident beam parallel to the prism axes showed a regular one-layer oblique reciprocal lattice, similar to that of kaolinite along Y i -directions. HRTEM imaging performed with the new computer-assisted minimal-dose system and an incident beam perpendicular to the prism axis showed stacking of most dioctahedral 1:1 layers with their pseudo-mirror plane perpendicular to the prism axis and an almost random, or rather, alternating lateral stagger to the right or left from the preceding layer, which corresponds to interlayer displacements of τ + and τ − in Zvyagin symbols, or layer displacements of t 1 and t 2 used to describe the stacking in kaolinite. This stacking feature explains the SAED pattern from the side of the prismatic grains and the two characteristic peaks on the tail of the 02,11 band in the XRD pattern. Based on these results, it is proposed that tubular halloysite initially forms as a hydrated one with the pseudo-mirror plane of the kaolinite layers perpendicular to the tube axis, then dehydrates with, possibly, partially hydrogen-bonded interlayers, and finally transforms to a prismatic one consisting of sectored flat layers with the complete hydrogen-bonded interlayers. During this transformation, stacking with comparable ratio and frequent alternation of τ + and τ − is formed, to minimize morphological change of the tubes.

An experimental and numerical investigation on wave‐mud interactions

Wave attenuation over a mud (kaolinite) layer is investigated via laboratory experiments and numerical modeling. The rheological behavior of kaolinite exhibits hybrid properties of a Bingham and pseudoplastic fluid. Moreover, the measured time‐dependent velocity profiles in the mud layer reveal that the shear rate under wave loading is highly phase dependent. The measured shear rate and rheological data allow us to back‐calculate the time‐dependent viscosity of the mud layer under various wave loadings, which is also shown to fluctuate up to 1 order of magnitude during one wave period. However, the resulting time‐dependent bottom stress is shown to only fluctuate within 25% of its mean. The back‐calculated wave‐averaged bottom stress is well correlated with the wave damping rate in the intermediate‐wave energy condition. The commonly adopted constant viscosity assumption is then evaluated via linear and nonlinear wave‐mud interaction models. When driving the models with measured wave‐averaged mud viscosity (forward modeling), the wave damping rate is generally overpredicted under the low wave energy condition. On the other hand, when a constant viscosity is chosen to match the observed wave damping rate (inverse modeling), the predicted velocity profiles in the mud layer are not satisfactory and the corresponding viscosity is lower than the measured value. These discrepancies are less pronounced when waves become more energetic. Differences between the linear and nonlinear model results become significant under low‐energy conditions, suggesting an amplification of wave nonlinearity due to non‐Newtonian rheology. In general, the constant viscosity assumption for modeling wave‐mud interaction is only appropriate for more energetic wave conditions.

Determination of the Contact Angles of Kaolin Intercalates of Oleochemicals Derived from Rubber Seed (HeveaBrasiliensis) and Tea Seed (CameliaSinensis) Oils by the Capillary Rise Method

Pristine kaolin was organically modified by employing derivatives of oleochemicals namely rubber seed oil (SRSO) and tea seed oil (STSO). Intercalation was attained by the entrance of hydrazine hydrate as co-intercalate. Characterization of the pristine kaolin and modified kaolin was done using powder X-ray diffraction which revealed increase in the interlayer basal spacing d-001 for the SRSO-modified and STSO-modified kaolins, confirming intercalation process. The FTIR studies further revealed that the fatty acid salts of rubber seed oil and tea seed oil were effectively intercalatedin the kaolinite layers as per the bands at 1564 cm-1and 1553 cm-1for SRSO-modified and STSO-modified kaolins respectively. The contact angle measurement using capillary rise method was performed to confirm that the pristine kaolin with initial contact angle value of ~45° was effectively modified and ‘wetted’ from hydrophilic state to hydrophobic state of ~90° for the SRSO-modified and STSO-modified kaolin.The determination of the contact angles of the kaolin was performed to confirm intercalation of the modified kaolin with the oleochemical derivatives.