Influence of octadecyl dihydrogen phosphate on the formation of active super-fine calcium carbonate

Ye, Sheng; Zhou, Bing; Zhao, Jingzhe; Tao, Nannan; Yu, Kaifeng; Tian, Yumei; Wang, Zichen

doi:10.1016/j.jcis.2003.11.062

Cited by 65 publications

(38 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These clusters are charged particles in equilibrium with their ions and they can grow or collide to produce CaCO 3 nuclei. Therefore, certain additives were introduced into the crystal growing medium to alter the surface charge of the growing nuclei and to inhibit the CaCO 3 growth [16][17][18][19]. Nano-CaCO 3 particles can be produced when the newly produced particles are stabilized by adjusting the surface potential of the particles.…”

Section: Introductionmentioning

confidence: 99%

Rice-like hollow nano-CaCO 3 synthesis

Ulkeryildiz¹,

Kilic²,

Ozdemir³

2016

Journal of Crystal Growth

View full text Add to dashboard Cite

a b s t r a c tWe have shown that Ca(OH) 2 solution is a natural stabilizer for CaCO 3 particles. We designed a CO 2 bubbling crystallization reactor to produce nano-CaCO 3 particles in homogenous size distribution without aggregation. In the experimental set-up, the crystallization region was separated from the stabilization region. The produced nanoparticles were removed from the crystallization region into the stabilization region before aggregation or crystal growth. It was shown that rice-like hollow nano-CaCO 3 particles in about 250 nm in size were produced with almost monodispersed size distribution. The particles started to dissolve through their edges as CO 2 bubbles were injected, which opened-up the pores inside the particles. At the late stages of crystallization, the open pores were closed as a result of dissolution-recrystallization of the newly synthesized CaCO 3 particles. These particles were stable in Ca(OH) 2 solution and no aggregation was detected. The present methodology can be used in drug encapsulation into inorganic CaCO 3 particles for cancer treatment with some modifications.

show abstract

Section: Introductionmentioning

confidence: 99%

Rice-like hollow nano-CaCO 3 synthesis

Ulkeryildiz¹,

Kilic²,

Ozdemir³

2016

Journal of Crystal Growth

View full text Add to dashboard Cite

show abstract

“…Other important ways to influence on the PCC particle morphology are the use of magnetic field, 12,13 high pressure, 14,15 or a specific additive. [16][17][18][19][20][21][22] The paper industry uses a huge amount of calcium carbonate as a filler component. The more filler is applied, the cost of the final product is lower.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Calcium Carbonate by Semicontinuous Carbonation Method in the Presence of Dextrans

Kontrec¹,

Ukrainczyk²,

Babić-Ivančić³

et al. 2011

Croat. Chem. Acta

View full text Add to dashboard Cite

Abstract. Precipitated calcium carbonate (PCC) was prepared by means of semicontinuous carbonation of Ca(OH) 2 suspension, at 35 and 45 °C and in the presence of non-ionic dextran and dextran sulfate. The carbonation process was regulated at different predetermined values of electrical conductivity, that corresponded to different concentrations of dissolved Ca(OH) 2 : 0.5 mS cm. The results of physicalchemical characterization of the product showed that calcite was the only polymorphic modification obtained in the whole range of experimental conditions investigated. In addition, it was found that morphology, crystal size distribution and specific surface area of PCC strongly depended on the electrical conductivity / concentration of dissolved Ca(OH) 2 , at which the process was performed: predominantly scalenohedral crystals of higher surface area (about 5 m 2 g −1) were produced at higher electrical conductivity, while at lower electrical conductivity predominantly rhomohedral calcite crystals of relatively low specific surface area were obtained. In the system of the highest electrical conductivity, κ 25 = 5.0 mS cm, and at 35 °C, the addition of non-ionic dextran significantly influenced the process by preventing the regulation. The crystals that appeared were in the form of irregular aggregates of high specific surface area, S ≈ 29 m 2 g −1. FT-IR and TG analyses indicated that the non-ionic dextran was adsorbed onto the calcite surface, most probably by relatively strong and specific interactions between oxygen from the hydroxyl groups of dextran molecules and calcium ions from the crystal surface. On the contrary, the anionic dextran (dextran sulfate) exerted minor effects in the course of semicontinuous carbonation process and in the properties of the final product, PCC. However, the analysis of the precipitate indicated that dextran sulfate was adsorbed at the surfaces, most probably by the weak and non-specific electrostatic interactions. (doi: 10.5562/cca1746)

show abstract

“…A method, presented in the works of a group of authors, was used to determine a coating degree [5,6,7]. The method consists in the following: 10 g of modified calcite is submerged in 100 ml of distilled water with periodical stirring with a glass rod.…”

Section: Determining Of Coating Degreementioning

confidence: 99%

“…Using the methods of surface calcite modifying by organic modifiers, type of surfactants, it is possible to convert its hydrophilic surface into hydrophobic [3,4]. As a measure of the achieved surface hydrophobicity of calcite, the degree of coating was taken that was presented by the group of authors in their works [5,6,7].…”

Section: Introductionmentioning

confidence: 99%