Wettability alteration of organo-vermiculites induced by layer charge and tailored bis-N-heterocyclic quaternary ammonium salts

Wettability is an important surface property that deserves to further explore the factors on its alteration.Series of bis-N-heterocyclic quaternary ammonium salts with different spacer length and N-heterocyclic headgroups(morpholinium(BMMB,BMMD and BMMH),piperidinium(BPMH)and piperazinium(BMPMH))have been synthesized and employed for altering the wettability of vermiculite and its derivates(Vts)treated by Li^(+)-saturated heating method.The results of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TG-DTG),scanning electron microscopy(SEM)and N_(2)adsorption/desorption isotherms indicate that all of the bis-N-heterocyclic quaternary ammonium salts have been successfully inserted into the vermiculite layers,leading to the organic monolayer.The results of capillary rise tests combined with Lipophilic to Hydrophilic Ratio(LHR)values unveil the wettability alteration of the organo-Vts.As the layer charge decreases,the hydrophilicity of the organo-Vts gradually increases,which is probably caused by the decline in binding sites.As the result of the change in spacer length of modifier,the wetting properties of morpholinium-based organo-Vts change in order of BMMD-Vts>BMMH-Vts>BMMB-Vts,and difference in N-heterocyclic headgroups leads to the sequence of wettability:BMPMH-Vts>BPMH-Vts>BMMH-Vts.Layer charge of Vt,spacer length and the type of the N-heterocyclic headgroup of modifier have the synergistic effect on the regulation of the wettability.

Preparation of Poly ( L-lactic acid ) / Vermiculites Composites by in situ Copolymerization of Lactic Acid and Hydroxylic Vermiculites

L-lactic acid (L-LA) based copolymer/hydroxylation vermiculites composites (PLLA-co-bis A/HVMTs) were prepared by in situ reaction among L-LA, adipic acid, and hydroxylation lamellar vermiculites (HVMTs) using bisphenol-A epoxy resin as chain extending agent. HVMTs were obtained by sulfuric acid-leaching of lamellar vermiculites (VMTs). The effects of sulfuric acid leaching on the VMTs structure were characterized by X-ray diffraction (XRD), 29Si magic-angle spinning nuclear magnetic resonance(29Si NMR), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA). FTIR, FE-SEM, and TGA were used to characterize the reaction activity of HVMTs. The results indicated that VMTs with increased hydroxyl groups had been successfully obtained and could react with -COOH of the reaction system. The amount of L-LA based copolymer grafted on the surface of HVMTs was more than 22%. The onset decomposition temperature of L-LA based copolymer grafted on the surface of HVMTs was 30℃ higher than that of free L-LA based copolymer.

Experimental study on thermal and mechanical properties of tailings-based cemented paste backfill with CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials

CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials(CEV)was prepared by atmospheric impregnation method.Using gold mine tailings as aggregate of cemented paste backfill(CPB)material,the CPB with CEV added was prepared,and the specific heat capacity,thermal conductivity,and uniaxial compressive strength(UCS)of CPB with different cement-tailing ratios and CEV addition ratios were tested,the influence of the above variables on the thermal and mechanical properties of CPB was analyzed.The results show that the maximum encapsulation capacity of expanded vermiculite for CaCl_(2)·6H_(2)O is about 60%,and the melting and solidification enthalpies of CEV can reach 98.87 J/g and 97.56 J/g,respectively.For the CPB without CEV,the specific heat capacity,thermal conductivity,and UCS decrease with the decrease of cement-tailing ratio.For the CPB with CEV added,with the increase of CEV addition ratio,the specific heat capacity increases significantly,and the sensible heat storage capacity and latent heat storage capacity can be increased by at least 10.74%and 218.97%respectively after adding 12%CEV.However,the addition of CEV leads to the increase of pores,and the thermal conductivity and UCS both decrease with the increase of CEV addition.When cement-tailing ratio is 1:8 and 6%,9%,and 12%of CEV are added,the 28-days UCS of CPB is less than 1 MPa.Considering the heat storage capacity and cost price of backfill,the recommended proportion scheme of CPB material presents cement-tailing ratio of 1:6 and 12%CEV,and the most recommended heat storage/release temperature cycle range of CPB with added CEV is from 20 to 40℃.This work can provide theoretical basis for the utilization of heat storage backfill in green mines.

Plasma-Catalytic Decomposition of 2,4-Dichlorophenol in a Dielectric Barrier Discharge with a Vermiculite ZiO2 Composite

The paper presents comparative kinetic characteristics of the decomposition of 2,4-dichlorophenol in a dielectric barrier discharge and a combined plasma-catalytic process. Vermiculite containing 5% zirconium was used as a catalyst. The destruction processes of 2,4-DCP proceed efficiently, the degree of decomposition increases in the combined plasma-catalytic process by a factor of 1.33 and reaches 80%. The experimental results were processed according to the first-order kinetic law (R2 > 0.97), according to which the effective constants (0.36 ± 0.04) and (0.51 ± 0.03) s-1 and the decomposition rates of 2,4-DCP (106 and 123 μmol/l·s) when treating model solutions without a catalyst and with vermiculite + Zr 5%, respectively, and the energy costs are 0.012 and 0.017 molecules/100eV. The main decomposition products present in the solution have been determined to be carboxylic acids, aldehydes, the contribution of which does not exceed 2%, as well as chloride ions, and in the gas phase they are carbon dioxide and molecular chlorine (the share of which does not exceed 1.5% of total chlorine content in the system).

Enhanced adsorption of Methylene Blue from aqueous solution by chitosan-g-poly(acrylic acid)/vermiculite hydrogel composites

A series of chitosan-g-poly （acrylic acid）/vermiculite hydrogel composites were synthesized and used as adsorbents for the investigation of the effect of process parameters such as vermiculite content, pH of dye solution, contact time, initial concentration of dye solution, temperature, ionic strength and concentration of surfactant sodium dodecyl sulfate on the removal of Methylene Blue （MB） from aqueous solution. The results showed that the adsorption capacity for dye increased with increasing pH, contact time and initial dye concentration, but decreased with increasing temperature, ionic strength and sodium dodecyl sulfate concentration in the present of the surfactant. The adsorption kinetics of MB onto the hydrogel composite followed pseudo second-order kinetics and the adsorption equilibrium data obeyed Langmuir isotherm. By introducing 10 wt.% vermiculite into chitosan-g-poly （acrylic acid） polymeric network, the obtaining hydrogel composite showed the highest adsorption capacity for MB, and then could be regarded as a potential adsorbent for cationic dye removal in a wastewater treatment process.

Ion adsorption components in liquid/solid systems

Experiments on Zn^2＋ and Cd^2＋ adsorptions on vermiculite in aqueous solutions were conducted to investigate the widely observed adsorbent concentration effect on the traditionally defined adsorption isotherm in the adsorbate range 25--500 mg/L and adsorbent range 10--150 g/L. The results showed that the equilibrium ion adsorption density did not correspond to a unique equilibrium ion concentration in liquid phase. Three adsorbate/adsorbent ratios, the equilibrium adsorption density, the ratio of equilibrium adsorbate concentration in liquid phase to adsorbent concentration, and the ratio of initial adsorbate concentration to adsorbent concentration, were found to be related with unique values in the tested range. Based on the assumption that the equilibrium state of a liquid/solid adsorption system is determined by four mutually related components： adsorbate in liquid phase, adsorbate in solid phase, uncovered adsorption site and covered adsorption site, and that the equilibrium chemical potentials of these components should be equalized, a new model was presented for describing ion adsorption isotherm in liquid/solid systems. The proposed model fit well the experimental data obtained from the examined samples.

Environmental Properties of Minerals and Contaminants Purified by the Mineralogical Method

The investigation of the environmental properties of minerals, i.e., environmental mineralogy, is a branch of science dealing with interactions between natural minerals and spheres of the Earth surface as well as a reflection of global change, prevention of ecological destruction, participation in biomineralogy, and remediation of environmental pollution. Pollutant treatment by natural minerals is based on the natural law and reflects natural self-purification functions in the inorganic world, similar to that of the organic world - a biological treatment. A series of case studies related to natural self-purification, which were mostly completed by our group, are discussed in this paper. In natural cryptomelane there is a larger pseudotetragonal tunnel than that formed by [MnO6] octahedral double chains, with an aperture of 0.462-0.466 nm2, filled with K cations. Cryptomelane might be a real naturally-occurring mineral of the active octahedral molecular sieve (OMS-2). CrⅥ-bearing wastewater can be treated by natural pyrrhotite, which is used as a reductant to reduce CrⅥ and as a precipitant to precipitate CrⅢ simultaneously. Batch experiments were conducted using the CTMAB-Montmorillonite as an adsorbent for aromatic contaminants (phenol, aniline, benzene, toluene and xylenes), which are detected frequently in the leaching water from municipal waste deposits around China. The CTMAB modification has proved very effective to enhance the adsorption capacity of the sorbent. Expansion of vermiculite develops loose interior structures, such as pores or cracks, inside briquettes, and thus brings enough oxygen for combustion and the sulfation reaction. Effective combustion of the original carbon reduces the amount of dust in the fly ash.

Fabrication, property characterization and thermal performance of composite phase change material plates based on tetradecanol-myristic acid binary eutectic mixture/expanded perlite and expanded vermiculite for building application

A binary eutectic mixture composed of tetradecanol(TD)and myristic acid(MA)was maximally absorbed into the microstructures of expanded perlite(EP)and expanded vermiculite(EVMT),respectively,through a self-made vacuum adsorption roller to prepare phase change material(PCM)particle(PCP).Then EP and EVMT-based composite PCM plates were respectively fabricated through a mold pressing method.The thermal property,chemical stability,microstructure and durability were characterized by differential scanning calorimeter(DSC),Fourier transform infrared spectroscope(FT-IR),scanning electron microscope(SEM)and thermal cycling tests,respectively.The results show that both PCPs have high latent heats with 110 J/g for EP-based PCP and more than 130 J/g for EVMT-based PCP,compact microstructure without PCM leakage,stable chemical property and good durability.The research results have proved the feasibility for the vacuum adsorption roller used in the composite PCM fabrication.Results of thermal storage performance experiment indicate that the fabricated PCM plates have better thermal inertia than common building materials,and the thermal storage performance of PCM plates has nonlinearly changed with outside air velocity and temperature increase.Therefore,PCM plates show a significant potential for the practical application of building thermal storage.

High-performance polymer electrolyte membranes incorporated with 2D silica nanosheets in high-temperature proton exchange membrane fuel cells

Silica nanosheets(SN)derived from natural vermiculite(Verm)were successfully incorporated into polyethersulfone-polyvinylpyrrolidone(PES-PVP)polymer to fabricate high-temperature proton exchange membranes(HT-PEMs).The content of SN filler was varied(0.1-0.75 wt%)to study its influence on proton conductivity,power density and durability.Benefiting from the hydroxyl groups of SN that enable the formation of additional proton-transferring pathways,the inorganic-organic membrane displayed enhanced proton conductivity of 48.2 mS/cm and power density of 495 mW/cm^(2) at 150℃ without humidification when the content of SN is 0.25 wt%.Furthermore,exfoliated SN(E-SN)and sulfonated SN(S-SN),which were fabricated by a liquid-phase exfoliation method and silane condensation,respectively,were embedded in PES-PVP polymer matrix by a simple blending method.Due to the significant contribution from sulfonic groups in S-SN,the membrane with 0.25 wt%S-SN reached the highest proton conductivity of51.5 mS/cm and peak power density of 546 mW/cm^(2) at150℃,48%higher than the pristine PES-PVP membranes.Compared to unaltered PES-PVP membrane,SN added hybrid composite membrane demonstrated excellent durability for the fuel cell at 150℃.Using a facile method to prepare 2D SN from natural clay minerals,the strategy of exfoliation and functionalization of SN can be potentially used in the production of HT-PEMs.

A two-dimension laminar composite protective layer for dendrite-free lithium metal anode

Lithium(Li)metal anodes with the high theoretical specific capacity(3860 mAh g^(-1))and most negative reduction potential(-3.04 V vs.standard hydrogen electrode)have been considered as an ultimate choice for energy storage devices with high energy density[1-4].However,the practical applications of Li metalbased batteries(LMBs)are confronted with two tough issues:Li dendrite growth induced by uneven Li depositions and unstable solid electrolyte interphase(SEI)(Fig.1a)[5,6].

Ultralow-weight loading Ni catalyst supported on two-dimensional vermiculite for carbon monoxide methanation

Nickel-based catalysts represent the most commonly used systems for CO methanation.We have successfully prepared a Ni catalyst system supported on two-dimensional plasma-treated vermiculite（2D-PVMT）with a very low Ni loading（0.5 wt%）.The catalyst precursor was subjected to heat treatment via either conventional heat treatment（CHT）or the plasma irradiation method（PIM）.The as-obtained CHT-Ni/PVMT and PIM-Ni/PVMT catalysts were characterized with scanning electron microscopy（SEM）,energy dispersive X-ray（EDX）,X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,inductively coupled plasma-atomic emission spectroscopy（ICP-AES）and high-angle annular dark field scanning transmission electron microscopy（HAADF-STEM）.Additionally,CHT-NiO/PVMT and PIM-NiO/PVMT catalysts were characterized with hydrogen temperature programmed reduction（H2-TPR）.Compared with CHT-Ni/PVMT,PIM-Ni/PVMT exhibited superior catalytic performance.The plasma treated catalyst PIM-Ni/PVMT achieved a CO conversion of93.5%and a turnover frequency（TOF）of 0.8537 s^-1,at a temperature of 450℃,a gas hourly space velocity of 6000 ml·g^-1·h^-1,a synthesis gas flow rate of 65 ml·min^-1,and a pressure of 1.5 MPa.Plasma irradiation may provide a successful strategy for the preparation of catalysts with very low metal loadings which exhibit excellent properties.

Dual-layer vermiculite nanosheet based hybrid film to suppress dendrite growth in lithium metal batteries

Lithium metal anode has become a favorable candidate for next-generation rechargeable batteries.However, the unstable interface between lithium metal and electrolyte leads to the growth of dendrites,resulting in the low Coulombic efficiency and even the safety concerns. Herein, a rigid-flexible dual-layer vermiculite nanosheet(VN) based organic-inorganic hybrid film on lithium metal anode is proposed to suppress dendrite growth and relieve volume fluctuations. The inner mechanically robust VN layer(3 μm thick) enhances the mechanical properties of the protective layer, while the outer polymer(4 μm thick) can enhance the flexibility of the hybrid layer. The Li | Li symmetric cell with protected lithium shows an extended life of over 670 h. The full cell with Li anode protected by dual-layer interface exhibits a better capacity retention of 80% after 174 cycles in comparison to bare Li anode with 94 cycles.This study provides a novel approach and a significant step towards prolonging lifespan of lithium metal batteries.

Evidence of melt/rock interaction in the Cr-spinel bearing wehrlite rocks of Bangriposi, India: Implications for nature of the metasomatic agent

Cr-spinel bearing wehrlite rocks of Bangriposi are found within the multiply deformed metasedimentary rocks of Singhbhum Group belonging to North Singhbhum Mobile Belt of eastern India. Detailed mineralogical and geochemical studies reveal that these rocks have suffered a two-stage alteration involving a deeper level modal and cryptic metasomatism and a subsequent shallower depth pervasive hydrothermal alteration. Cryptic metasomatism is defined by elevated LREE contents of the wehrlite and its clinopyroxne grains. Metasomatism induced changes in the modal mineralogy of the rocks include the absence of primary orthopyroxene grains, presence of secondary diopside-phlogopite（now present as vermiculite） defining disequilibrium reaction textures and secondary orthopyroxene rims around serpentinized olivine. The mineralogical and geochemical changes due to the metasomatic event present a contrasting picture in regard to the metasomatic history of the rocks. Possible scenarios involving a single stage or multiple stage metasomatism events have been discussed while explaining the metasomatic reactions that took place. An attempt has been made to estimate the REE concentrations of the final equilibrating melt from REE contents of clinopyroxene grains of the wehrlite. The possibility of the LREE-enriched equilibrating melt of the wehrlite rocks（the deeper level metasomatic agent） being similar to residual melts from the E-MORB type parental melts of nearby gabbro suite has been ruled out by geochemical modeling. REE abundance patterns of several natural enriched melts have been compared with REE pattern of calculated LREE-enriched equilibrating melt of the wehrlite and most resemblance has been observed with calcic and potassic melts. It is therefore suggested that the Cr-spinel bearing wehrlite rocks of Bangriposi has been affected by a calcio-potassic melt in deeper level, prior to the shallow level serpentinization event.

Characterization and Modification of a Clay Mineral Used in Adsorption Tests

Clay minerals are widespread in natural systems and have been widely used for the removal of pollutants. In this study, natural expanded vermiculite was used in adsorption tests to remove ammonium nitrogen from landfill leachate. The modification of vermiculite was carried out using NaOH and HCl, and for both modifications the best concentration was 0.1 mol/L. The results produced by XRD (X-ray diffraction) showed that Al replaced K after modification of the vermiculite using HCl and that Mg and Na replaced K after modification using NaOH. It was observed that the adsorption capacity increased as the percentage in mass of K diminished. The Langmuir is the isotherm that presents the best fit of the data, and the values of RL (the Langmuir coefficient) suggest that the adsorption is linear. The thermodynamic parameters indicate that the process is spontaneous and endothermic, that there is a high affinity between the adsorbate and the adsorbent, and that physical adsorption is prevalent.

Microstructure and Characterization of Capric-stearic Acid/Modified Expanded Vermiculite Thermal Storage Composites

In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.

Effect of Modified Vermiculite on the Interface of a Capric Acid-expanded Vermiculite Composite Phase Change Material with Phase Transition Kinetics

A new type of capric acid(CA)-acid expanded vermiculite(AEV) composite phase change material(PCM) with improved adsorption ability and interface adhesive strength was developed. Through the analysis of non-isothermal phase transition kinetics, modified vermiculite was observed to change and affect the phase transformation mechanism of the composite. AEV was treated with hydrochloric acid to improve the specific surface area and micro-pore structure. The surface area measured by BET increased from 81.94 m^2/g for expanded vermiculite(EV) to 544.13 m^2/g for AEV. CA-EV and CA-AEV composite PCMs were prepared by direct impregnation. The non-isothermal phase transition isotherms of CA-EV and CA-AEV were recorded by DSC at different heating rates(1, 5, 10, 15, and 20 ℃/min), which indicated that the phase transition rate increased with the heating rate and the phase transition process changed. Kinetics parameters were analyzed by a double extrapolation method. The activation energy(E) under the original state(E_(α→0)) of CA-AEV and CA-EV was 1 117 kJ/mol and 937 kJ/mol, respectively, and 1 205 kJ/mol and 1 016 kJ/mol under the thermal equilibrium state(E_(β→0)). The most probabilistic mechanism function of CA-AEV satisfied G(α)=α^(2/3), which followed the Mample special rule, and the function of CA-EV satisfied G(α)=[(1+α)^(1/3)-1]~2, which followed the anti-Jander function.

Transition of TiO2 in TiO2/Vermiculite Nanocomposites

The TiO2/vermiculite composites were prepared by in-situ hydrolyzing reaction and in-situ dehydrating reaction of tetrabutyl titanate-hexadecyl trimethyl ammonium bromide intercalated vermiculite. The structural phase transition of TiO2 in TiO2/vermiculite composites calcined at different temperatures was characterized by using XRD and Raman. The results show that at calcination temperature of 800℃ appeared the anatase phase of TiO2 in TiO2/vermiculite nanocomposites, while pure TiO2 is all converted to rutile at the same temperature. The average crystal size of TiO2 in TiO2/vermiculite nanocomposites and pure TiO2 both increase with the calcination temperature. The average grain size of TiO2 in TiO2/vermiculite nanocomposites is less than that of pure TiO2 at the same calcination temperature. The results also show that the silicon-oxygen structure in layered vermiculite structure can effectively depress the phase transformation from anatase to rutile, thus enhancing the transition temperature and inhibitting the growth of anatase crystals.

Adsorption behavior and wettability alteration of bis-imidazolium salts on vermiculite:Experimental and theoretical studies

For further understanding the wettability alteration induced by organic salts,series of bis-imidazolium salts(EBMI,TBMI,HBMI,OBMI and DBMI) were employed for investigating their adsorption behavior and wettability alteration on vermiculite(Vt) by experimental and theoretical studies.The characterization results indicated that all bis-imidazolium salts had been loaded on Vts.The adsorption results showed that EBMI,TBMI,HBMI,OBMI and DBMI on Vt reached equilibrium of 0.159,0.156,0.145,0.114 and 0.084 mmol g-1 around 30 min at 25℃,respectively,which were sensitive to ionic strength and pH.Langmuir,statistical physical modelling and pseudo-second-order models could be well fitted with the adsorption data,and thermodynamic parameters suggested that the adsorption processes of bis-imidazolium salts were endothermic and spontaneous,indicating that the resultant bis-imidazolium salts could be self-assembled onto Vt in the form of the monolayer.Results of molecular dynamic simulation showed that bis-imidazolium salts were adsorbed on Vt with the lying-flat configuration,and the electrostatic interaction acted as the main interaction mechanism,which were consistent with that obtained experimentally.Changes of wettability of Vt induced by bis-imidazolium salts were verified by capillary rise experiments.Interestingly,the wettability of organo-Vts varied with the spacer length and the order was as follows:EBMI-Vt <TBMI-Vt <HBMI-Vt <OBMI-Vt <DBMI-Vt,which could be explained by their arrangements,hydrophobicity as well as the interaction energies.The longer the spacers of bisimidazolium salts,the greater the absolute values of the interaction energy,the less the adsorbed bisimidazolium salts,while the more hydrophobic of organo-Vt.This work aimed at revealing the adsorption behavior,mechanism as well as effect of bis-imidazolium salts on wettability alteration of negatively charged mineral surface,providing some information for the selection of flooding agent for enhanced oil recovery and wettability modifier.

Adsorption of Ammonium and Heavy Metal Ions on Industrial Vermiculite from the Yuli Mine in Xinjiang, China

The present work discusses the mineralogy, saturated adsorption of ammonium and adsorption of heavy metal ions （Cu^2＋, Pb^2＋ and Zn^2＋） on industrial vermiculite samples from the Yuli Mine in Xinjiang Autonomous Region. The saturated adsorption capacity of ammonium and the affection factors of adsorption of Cu^2＋, Pb^2＋ and Zn^2＋ are discussed on the basis of the mineralogical characteristics of the industrial vermiculite samples. The saturated adsorption capacities of ammonium are between 56.02 and 98.42 mmol/100g. The time of adsorption equilibrium is about 30-60 min, and the pH values and concentration of the ion solution significantly affect the adsorption capacities of the heavy metal ions. The adsorption capabilities of the heavy metal ions on industrial vermiculite are almost the same in the low ion concentration solutions, characterized by a sequence of Zn^2＋〉Pb^2＋〉Cu^2＋ for adsorption capacity in solutions with relatively high ion concentration. The results have practical significance for the application of the industrial vermiculite to treating wastewater containing ammonium or heavy metal ions.

The Preparation and Characterization of Vermiculite Hydrosol

The dispersibility of vermiculite is the key factor that affects the application of vermiculite.In this paper,the milled natural vermiculite was pillared by organic quaternary ammonium salts.Then the pillared vermiculite was ground and homogenized under the existence of dispersive agent to form a stable vermiculite hydrosol system.Small angle X-ray diffraction(SA-XRD),fourier transform infrared spectroscopy(FTIR),and thermogravimetric analyses(TGA)were used to characterize the structure and thermal property of the vermiculite.The results indicate that the exfoliated vermiculite is successfully obtained.The analyses of laser particle size analyzer,transmission electron microscope(TEM),and Tyndall phenomenon analyzer demonstrate that the vermiculite hydrosol prepared is a stable hydrosol system.