PMMA/reactive nanoclay nanocomposites were prepared by emulsion polymerization using two different reactive nanoclays. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) results confirmed that the reactive nanoclays, kaolinite and montmorillonite, were obtained by the silylation reaction and the double bonds were grafted onto the edges and surfaces of the nanoclays. The presence of reactive nanoclays could increase the average molecular weights, the glass transition temperatures (Tg) and improve the thermal properties of nanocomposite. The tensile properties, Young’s modulus, and the aging properties of the nanocomposite films were also enhanced while the light transmittance decreased. Furthermore, the nanocomposites with the reactive kaolinite presented better performances than that with the reactive montmorillonite. Finally, the action mechanism of the reactive nanoclays to the performances of PMMA/reactive nanoclay nanocomposites was proposed.

High-purity K3NaMgCl6 was synthesized from magnesia.The factors affecting the purity of K3NaMgCl6 were investigated. The hygroscopic property of K3NaMgCl6 was studied. The preparation process of K3NaMgCl6 was investigated by X-ray diffraction analysis and differential scanning calorimetry analysis, and the reaction mechanism involved was determined. Then, magnesium metal was prepared by an electrochemical method using K3NaMgCl6 as raw material. The electrolytic parameters were measured, and the electrochemical behavior of magnesium ion in K3NaMgCl6 molten salt was investigated. Magnesia content in K3NaMgCl6 achieved 0.02 wt % under the optimum conditions. K3NaMgCl6 had a lower hygroscopy at room temperature and had a lower tendency to hydrolyze at high temperature. The purity of the obtained magnesium metal was 99.4 wt %, and the current efficiency in the electrolysis process was 94.8%.

Nano-sized ZSM-5 aggregates have been rapidly synthesized from leached metakaolin by solid-like state conversion. The influence of synthesis conditions such as TPA+/SiO2, NaOH/SiO2 and SiO2/Al2O3 molar ratios on the final products was investigated. The properties of nano-sized ZSM-5 aggregates were characterized by XRD, SEM, HRTEM, 29Si and 27Al MAS NMR, NH3-TPD, TG, N2 adsorption–desorption and particle size analysis. The results clearly showed that nano-sized ZSM-5 aggregates could be obtained within 2 h via solid-like state conversion. SEM revealed that the obtained ZSM-5 aggregates were irregular spheres that consisted of nano-sized crystallites with 30–50 nm. The crystallization process indicated that the size of flaky raw materials gradually decreased and formed nano-sized particles as time prolonged. Therefore, the transformation mechanism followed the solution mediated mechanism, though only a little water was contained in the system. Compared with the conventional hydrothermal route, the solid-like state conversion not only significantly shortened the crystallization time, but also totally avoided the emission of waste liquids. In addition, for the methanol dehydration reaction, the nano-sized ZSM-5 aggregates obtained by this method showed much better catalytic performance, C2–C4 olefin selectivity and longer lifetime to endure coke deposition than the sample obtained by the hydrothermal route.

•Adopte solid waste coal-series kaolinite as the only Si and Al resources to synthesize ZSM-5.•Synthesize ZSM-5 without organic template.•Synthesize ZSM-5 in solid–liquid heterogeneous phase system.•Activation energy for induction and crystal growth are 78.3 and 68.5 kJ/mol, respectively.Calcined coal-series kaolinite was used as a combinational Si and Al sources to synthesize ZSM-5 via an organic template-free method. The influence factors such as ball-milling time, H2O/SiO2 ratios, and NaOH/SiO2 ratios have been investigated systematically. Furthermore, crystallization kinetics experiments were performed at 170–190 °C for periods of time ranging from 6 to 96 h, and obtained the curves as a function of time. The obtained samples were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that ZSM-5 with excellent crystallinity could be obtained without organic template. Furthermore, mechanical treatment and synthesis conditions could influence the crystallinity and purity significantly. According to Arrhenius equation, the apparent activation energy for induction and growth were 78.3 and 68.5 kJ/mol, respectively.Highly crystalline ZSM-5 was successfully synthesized by template-free method from coal-series kaolinite. The results demonstrated that mechanical treatment and conditions of synthesis influenced the crystallinity and purity of samples significantly. Apparent activation energy for induction and growth were 78.3 and 68.5 kJ/mol, respectively, which was calculated from Arrhenius equation.

•Adopt acid leached kaolinite as the only Si and Al resources.•Synthesize ZSM-5 without an organic template.•Mechanical treatment with ball milling.•Synthesize ZSM-5 in a solid-liquid heterogeneous phase system.ZSM-5 was successfully synthesized by a template-free method using coal-series kaolinite as the only silica and alumina source. The physicochemical properties of obtained samples were characterized by XRD, SEM, FT-IR and nitrogen adsorption. According to the results, the relative crystallinity of template free ZSM-5 was ca. 94.2%, and crystal size was about 4.0 μm. Due to the absence of an organic template during the synthesis process, the obtained ZSM-5 samples have an opened pore system and could avoid calcination, which could reduce the cost and avoid generating environmental pollution. Furthermore, the process of heterogeneous synthesis for ZSM-5 using kaolinite as a silica source without an organic template has been discussed.

SAPO-34 molecular sieve was hydrothermally synthesized using metakaolin as the single Si and partial Al source. Crystallization mechanism of SAPO-34 and transformation processes of metakaolin were investigated by studying effect of metakaolin content on the products, and Si, Al and P coordination environments of the products by XRD, SEM, EDX, N2 adsorption–desorption and NMR. The results showed that SAPO-34 with high purity could be prepared within a wide range of metakaolin content. Synthesis of SAPO-34 with all Si in isolated state demonstrated that SAPO-34 crystallization proceeded by a solution–mediated transport mechanism. Increase of the Si/P ratio in the medium caused increase of Si content in the newly formed SAPO-34 lattice. Transformation processes of metakaolin were followed by (1) dissolution of the Al–O and Si–O layers, (2) appearance of the primary building units (PBUs) in a low Si content, (3) initial crystallization of SAPO-34 in isolated Si state, (4) occurrence of the PBUs in a high Si content, (5) incorporation of Si domains into SAPO-34 crystals and (6) formation of the Si-rich amorphous materials. The results drawn are useful to understand crystallization mechanisms of SAPO molecular sieves from metakaolin and from other Si and/or Al chemicals.Graphical abstractHighlights► SAPO-34 with all lattice Si in isolated state is prepared from metakaolin. ► SAPO-34 crystal growth proceeds via a solution-mediation mechanism. ► The Si/P ratio increase in the medium causes Si content increase in the lattice. ► Accordingly, transformation processes of metakaolin are divided in six steps.

Ammonium illite with hierarchical flower-like structure was synthesized from coal series kaolin under hydrothermal condition at 300 °C for 1 h. The product was characterized by X-ray powder (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the flower-like ammonium illite is constructed by nanosheets with thickness of ca. 20 nm and a diameter of ca. 400 nm. New phase was obtained by calcination of above product at 700 °C for 2 h, and the flower-like morphology was retained after calcination. Furthermore, the specific surface area of ammonium phase powder was calculated to be 197.2 m2/g by BET measurement. The possible formation mechanism for flower-like ammonium illite was proposed and discussed.Highlights► Fist time, nanolayer and flower-like material were synthesized from kaolin. ► The raw material is cheap and easily available in China. ► The process of this method is simple and fast. ► The product has relatively high specific surface area of 197 m2/g.

Large-mesoporous Al2O3 has been successfully synthesized from calcined coal-series kaolin by using cetyltrimethylammonium bromide(CTAB) as template at room temperature. After calcined at 700 °C, the as-synthesized samples have transformed to mesoporous γ-Al2O3. The mesoporous γ-Al2O3 has a specific area of 253.4 m2 g−1, large pore volume of 1.487 cm3 g−1, and an average pore diameter of 12.9 nm. TEM images show that the calcined mesoporous alumina has wormhole-like pores without long-range ordered framework. A probable formation mechanism of large-mesoporous γ-Al2O3 is also proposed.Highlights► Leachate of coal-series kaolin as Al resource. ► Large-mesoporous γ-Al2O3 have been synthesized at room temperature. ► γ-Al2O3 have surface area of 357.7 m2 g−1 and pore volume of 1.744 cm3 g−1.

A method was proposed for the preparation of high-purity anhydrous magnesium chloride by using magnesium chloride hexahydrate and ammonium chloride as raw materials, and alumina as covering agent. X-ray diffraction was employed to investigate the process. The mechanism involved in the process was proposed. The factors affecting the purity of anhydrous magnesium chloride were investigated. Dehydrated ammonium carnallite was formed in the process to facilitate the dehydration process. Alumina as covering agent can guarantee that the formation of high-purity anhydrous magnesium chloride was obtained. The content of magnesia in anhydrous magnesium chloride was 0.02 pct under the optimum conditions: molar ratio of ammonium chloride to dehydrated magnesium chloride was 2:1, thickness of alumina 1.3 cm, reaction temperature 723 K (450 °C), reaction time 1 hour, and the number of crystallized water 0.6 to 2.2.

High-purity anhydrous magnesium chloride was prepared by using magnesia and ammonium chloride as reactants, alumina as covering agent. The process was characterized by X-ray diffraction and thermogravimetric and differential scanning calorimetry analysis. The reaction mechanism involved in the process was proposed and discussed. In addition, the effects of molar ratio of ammonium chloride to magnesia, thickness of the covering agent (alumina), reaction temperature, and reaction time on the purity of anhydrous magnesium chloride were investigated. The content of magnesia in anhydrous magnesium chloride was achieved 0.014% under the optimum conditions: ammonium chloride and magnesia with the molar ratio of NH4Cl:MgO = 5:1 were mixed evenly. Alumina with the thickness of 1.1 cm was used as a covering agent. The mixture was maintained at 450 °C for 1.5 h for the complete reaction, and then calcined at 700 °C for 0.5 h to obtain well-sintered anhydrous magnesium chloride.

Calcined natural kaolinite (i.e. metakaolin) was used as a combinational Si and Al source to synthesize SAPO-5, -11, -20, -34, -44, and -47. The reactivity of metakaolin with related chemicals was studied, and the solid structural evolution process of SAPO-34 was exemplified to show the crystallization mechanism of SAPOs from kaolinite. The results indicated that the products had excellent crystallinity. The Si and/or Al of metakaolin had good coordination capability with related ligands. The crystallization process of SAPO-34 from kaolinite is summarized as three stages. In the first stage of calcination (at 1073 K), kaolinite is destructured and activated. In the second stage of aging and initial heating, the surface of metakaolin is gelated and the coordinated units are stripped down to transform into the primary building units (PBUs) with increasing temperature. At a desirable temperature, the PBUs stack to form the nuclei. In the final step, crystallization is triggered when the mixture is heated up to 423 K. NMR results illustrated that Si directly participated in the crystallization of SAPO-34 mainly as Si monomer state. Formation of SAPO-34 from kaolinite, as well as other SAPOs, is believed to proceed following an activation–gelation–crystallization mechanism.Graphical abstractResearch highlights► SAPO-5, -11, -20, -34, -44, and -47 were synthesized from natural kaolinite. ► Crystallization of SAPOs followed an activation–gelation–crystallization mechanism. ► Si participated in the crystallization of SAPOs mainly as Si monomer state.

The white and regular octahedral crystals of magnesium chloride hexammoniate are prepared by reaction crystallization between magnesium chloride and ammonia gas in ethylene glycol solution. The solubility of magnesium chloride hexammoniate in ethylene glycol solution saturated by ammonia gas has been determined by use of the ethylenediaminetetraacetic acid disodium salt (EDTA) titration method in the temperature range from (5 to 37.5) °C.

Nano-sized ZSM-5 aggregates have been rapidly synthesized from leached metakaolin by solid-like state conversion. The influence of synthesis conditions such as TPA+/SiO2, NaOH/SiO2 and SiO2/Al2O3 molar ratios on the final products was investigated. The properties of nano-sized ZSM-5 aggregates were characterized by XRD, SEM, HRTEM, 29Si and 27Al MAS NMR, NH3-TPD, TG, N2 adsorption–desorption and particle size analysis. The results clearly showed that nano-sized ZSM-5 aggregates could be obtained within 2 h via solid-like state conversion. SEM revealed that the obtained ZSM-5 aggregates were irregular spheres that consisted of nano-sized crystallites with 30–50 nm. The crystallization process indicated that the size of flaky raw materials gradually decreased and formed nano-sized particles as time prolonged. Therefore, the transformation mechanism followed the solution mediated mechanism, though only a little water was contained in the system. Compared with the conventional hydrothermal route, the solid-like state conversion not only significantly shortened the crystallization time, but also totally avoided the emission of waste liquids. In addition, for the methanol dehydration reaction, the nano-sized ZSM-5 aggregates obtained by this method showed much better catalytic performance, C2–C4 olefin selectivity and longer lifetime to endure coke deposition than the sample obtained by the hydrothermal route.