In this paper, the effect of ionic liquids on the CaCO3 crystal growth has been studied for the first time. The obtained CaCO3 crystals were charactered by the X-ray diffraction and scanning electron micrographs. The ...In this paper, the effect of ionic liquids on the CaCO3 crystal growth has been studied for the first time. The obtained CaCO3 crystals were charactered by the X-ray diffraction and scanning electron micrographs. The results showed that the control ability of ionic liquids for CaCO3 crystals growth was dependent on the counter anion very much.展开更多
The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed ...The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed the crystal orientation of nacreous layers with different color prepared from fresh water clams Hyriopsis cumingii Lea by X ray diffraction . The results show that the crystal CaCO 3 orientation on specific plane is responsible for the color of pearl and nacreous pearl color.展开更多
Submicrometer-sized, spherical vaterite particles were synthesized by solid-state reaction at room temperature in the presence of poly(acrylic acid)(PAA). The obtained products were characterized by XRD, IR and SEM. I...Submicrometer-sized, spherical vaterite particles were synthesized by solid-state reaction at room temperature in the presence of poly(acrylic acid)(PAA). The obtained products were characterized by XRD, IR and SEM. It was revealed that with increasing PAA amount, the crystal polymorph of CaCO 3 particles varied gradually from pure calcite through a mixture of calcite and vaterite to pure vaterite, and the particle size decreased generally. It was proposed that in solid-state reaction, PAA induced the formation of vaterite and the phase transformation from vaterite to calcite was prevented completely due to the absence of H 2O, resulting in the formation of pure vaterite particles.展开更多
利用三聚氰胺和碳酸钙成功合成了一种新型吸附剂CaCO 3/g-C 3 N 4。通过XRD,FT-IR,SEM,TEM和BET对CaCO 3/g-C 3 N 4的结构进行深入研究。实验结果表明:CaCO 3/g-C 3 N 4对结晶紫(CV)具有快速、高效的吸附性能(89.34%)和出色的吸附容量(1...利用三聚氰胺和碳酸钙成功合成了一种新型吸附剂CaCO 3/g-C 3 N 4。通过XRD,FT-IR,SEM,TEM和BET对CaCO 3/g-C 3 N 4的结构进行深入研究。实验结果表明:CaCO 3/g-C 3 N 4对结晶紫(CV)具有快速、高效的吸附性能(89.34%)和出色的吸附容量(1209.75 mg/g)。CaCO 3/g-C 3 N 4对CV的吸附符合准二级动力学和Langmuir等温吸附模型。同时,基于吸附前后吸附剂的FT-IR和XPS分析,得出π-π堆积,n-π相互作用和氢键协同效应是CaCO 3/g-C 3N 4选择性吸附CV的重要因素。展开更多
Calcium carbonate, the main component of lime, has been widely used in industry due to its stability and economy. Calcium carbonate has three types of crystalline polymorphism, calcite, aragonite and vaterite, each wi...Calcium carbonate, the main component of lime, has been widely used in industry due to its stability and economy. Calcium carbonate has three types of crystalline polymorphism, calcite, aragonite and vaterite, each with different properties. Therefore, the control of crystal polymorphism is required for industrial applications. In addition, the control of crystal size and shape is similarly required for different applications. In this study, the effect of SrCO<sub>3</sub> on the size control of fine aragonite-type calcium carbonate crystals by uniform urea precipitation and the effect of SrCO<sub>3</sub> addition was investigated by adding solid strontium carbonate and dissolved strontium carbonate. The addition of solid strontium carbonate affected the crystal polymorphism and size of the calcium carbonate produced, depending on the properties of the solid particles and the amount of SrCO<sub>3</sub> added. Experiments on the addition of dissolved SrCO<sub>3</sub> showed that the supersaturation formation rate could be controlled to control the crystal polymorphism.展开更多
文摘In this paper, the effect of ionic liquids on the CaCO3 crystal growth has been studied for the first time. The obtained CaCO3 crystals were charactered by the X-ray diffraction and scanning electron micrographs. The results showed that the control ability of ionic liquids for CaCO3 crystals growth was dependent on the counter anion very much.
文摘The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed the crystal orientation of nacreous layers with different color prepared from fresh water clams Hyriopsis cumingii Lea by X ray diffraction . The results show that the crystal CaCO 3 orientation on specific plane is responsible for the color of pearl and nacreous pearl color.
文摘Submicrometer-sized, spherical vaterite particles were synthesized by solid-state reaction at room temperature in the presence of poly(acrylic acid)(PAA). The obtained products were characterized by XRD, IR and SEM. It was revealed that with increasing PAA amount, the crystal polymorph of CaCO 3 particles varied gradually from pure calcite through a mixture of calcite and vaterite to pure vaterite, and the particle size decreased generally. It was proposed that in solid-state reaction, PAA induced the formation of vaterite and the phase transformation from vaterite to calcite was prevented completely due to the absence of H 2O, resulting in the formation of pure vaterite particles.
文摘Calcium carbonate, the main component of lime, has been widely used in industry due to its stability and economy. Calcium carbonate has three types of crystalline polymorphism, calcite, aragonite and vaterite, each with different properties. Therefore, the control of crystal polymorphism is required for industrial applications. In addition, the control of crystal size and shape is similarly required for different applications. In this study, the effect of SrCO<sub>3</sub> on the size control of fine aragonite-type calcium carbonate crystals by uniform urea precipitation and the effect of SrCO<sub>3</sub> addition was investigated by adding solid strontium carbonate and dissolved strontium carbonate. The addition of solid strontium carbonate affected the crystal polymorphism and size of the calcium carbonate produced, depending on the properties of the solid particles and the amount of SrCO<sub>3</sub> added. Experiments on the addition of dissolved SrCO<sub>3</sub> showed that the supersaturation formation rate could be controlled to control the crystal polymorphism.
