Introduction

Silica particles are spherical nano and micron silica particles with uniform particle size distribution prepared by St?ber method using ethyl orthosilicate as raw material. The particle size and size distribution of silica particles can be adjusted by adjusting reaction temperature, reaction time and concentrations of NH4OH, H2O and TEOS. The silica particles at the end of Si-OH have hydrophilicity, chemical activity and long-term stability in organic solvents and aqueous solutions. The hydroxyl group on the surface of silica particles can bind a variety of substances to the particle surface, improve the surface state of the particles, and achieve chemical modification. Different functional groups such as COOH and NH2 can be introduced to functionalize the surface. Various biomolecules such as streptavidin, avidin and protein A can be covalently bound to enhance the biological targeting of silica particles.

Biotyscience can supply high-quality silica particles, and can also customize according to the needs of customers. The company's products have been widely used in biomedicine, optics, electronics, catalysis, sensors, drug carriers, jewelry, polymer modification and many other industrial fields[1-7].

Preparation Method

Chemical precipitation method: Using sodium silicate as the silicon source, ammonium chloride as the precipitant, and surface active agents cetyltrimethylbromide (CTAB) and ethanol, silica nanoparticles with small particle size and narrow distribution were synthesized by chemical precipitation method.

Gas phase route: The raw materials used for the preparation of nano silica by gas-phase method are mainly volatile and hydrolyzable organic silanes, among which the most common are halogenated silanes such as silicon tetrachloride and methyl trichlorosilane. Silica particles are generated by high-temperature hydrolysis and condensation of halogenated silane in a hydrogen oxygen flame, followed by rapid cooling. The particles undergo post-treatment processes such as aggregation, gas-solid separation, and deacidification to obtain the product.

Sol–gel method (St?ber method)[8]: The main principle of the St?ber method is to control the hydrolysis and condensation process of tetraethyl orthosilicate (TEOS) in alcohol–water system with certain amount of ammonia. Specifically, Ethanol (≥99.7%), ammonium hydroxide (28%) and TEOS (≥99.5%) were used to prepare monodisperse silica particles. The adopted concentration of ethanol and TEOS is 10 and 0.21 mol/l, respectively. A solution of alcohol and water with 2 mol/l ammonia was prepared, and TEOS was rapidly added into the solution. The mixture was placed on a magnetic stirring apparatus under different stirring rates for 24 h. Then the silica particles can be gathered after freeze-drying process.

Application

Nucleic acid separation;

Cell separation;

Immunoassay;

Biomedical testing[1];

Catalytic carrier;

High performance polymer additives;

Polymer nanocomposite filler[9];

Particle size standard material.

Advantages

Highly uniform particle size;

Extremely stable;

Good dispersion.

Reference

1 Shangguan J., Li Y., He D., et al. (2015). A combination of positive dielectrophoresis driven on-line enrichment and aptamer-fluorescent silica nanoparticle label for rapid and sensitive detection of Staphylococcus aureus. Analyst. 140(13), 4489–4497. https://doi.org/10.1039/C5AN00535C

2 Chevalier Y., Bolzinger M.A. (2013). Emulsions stabilized with solid nanoparticles: pickering emulsions. Colloids Surf. A. 439, 23–34. https://doi.org/10.1016/j.colsurfa.2013.02.054

3 Shahabi S., Treccani L., Dringen R., et al. (2015). Modulation of silica nanoparticle uptake into human osteoblast cells by variation of the ratio of amino and sulfonate surface groups: effects of serum. ACS Appl. Mater. Interfaces. 7(25), 13821–13833. https://doi.org/10.1021/acsami.5b01900

4 Zhu M., Zhu Y., Zhang L., et al. (2016). Preparation of chitosan/mesoporous silica nanoparticle composite hydrogels for sustained co-delivery of biomacromolecules and small chemical drugs. Sci. Technol. Adv. Mater. 14(4), 045005. https://doi.org/10.1088/1468-6996/14/4/045005)

5 Yun J., Wang W., Kim S.M., et al. (2015). Light trapping in bendable organic solar cells using silica nanoparticle arrays. Energy Environ. Sci. 8(3), 932–940. https://doi.org/10.1039/C4EE01100G)

6 Xiao D., Jia H.Z., Ma N., et al. (2015). A redox-responsive mesoporous silica nanoparticle capped with amphiphilic peptides by self-assembly for cancer targeting drug delivery. Nanoscale. 7(22), 10071–10077. https://doi.org/10.1039/C5NR02247A

7 Appiah-Ntiamoah R., Jadhav A.H., Puguan J.M.C., et al. (2015). A silica nanoparticle supported fluorescence ‘turn-on’ fluoride ion sensing system with tunable structure and sensitivity. RSC Adv. 5(39), 30526–30536. https://doi.org/10.1039/C5RA02158H

8 Liang, X., Lian, L., Liu, Y., et al. (2016). Controlled synthesis of monodisperse silica particles. Micro & Nano Letters. 11(9), 532–534. https://doi.org/10.1049/mnl.2016.0189

9 Elias, L., Fenouillot, F., Majesté, J.C., et al. (2008). Immiscible polymer blends stabilized with nano-silica particles: Rheology and effective interfacial tension. Polymer. 49(20), 4378–4385. https://doi.org/10.1016/j.polymer.2008.07.018

Ordering Information

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