What is a silica nanoparticle?
A silica nanoparticle is an inorganic chemical material. Its appearance is amorphous white powder with particle size ranging from 1 to 100 nanometers. The microstructure is spherical and has a flocculent and reticulated granular structure. If you think these are all the properties of silica particles, then you are wrong. Silica particles are not only a brilliant pearl in the field of chemistry, but with the prosperity of nanotechnology, it has gradually moved to the stage of biology and medicine. Let me show you the true colors of silica nanoparticles!

How to get silica nanoparticles?
l Physical method

The physical method generally refers to mechanical pulverization. Ultrafine jet mills or high-energy ball mills are used to pulverize aggregates of SiO2 to obtain ultrafine products having a particle size of 1 to 5 μm. The method is simple in process but easy to bring in impurities, the powder property is difficult to control, the preparation efficiency is low, and the particle size distribution is wide.

l Chemical method

The chemical method can produce ultrafine SiO2 particles which are pure and have a uniform particle size distribution. Chemical methods include chemical vapor deposition (CVD), liquid phase, and ion exchange, precipitation, and sol-gel methods. The main production method is a gas phase method using silicon tetrachloride as a raw material. A precipitation method using sodium silicate and an inorganic acid as a raw material, and a sol-gel method using silicate or the like as a raw material.

Main uses of silica nanoparticles
The applications of silica nanoparticles are quite extensive. First and foremost, we mainly introduce the breakthroughs and applications of nano-silica particles in the biomedical field in recent years. After that, add its main use in other areas.

l As a new antibacterial material

Due to the large specific surface area of nano-silica, super-porosity structure on the surface, superior adsorption capacity and singular physicochemical properties, we can design functional ions such as silver ions uniformly into the mesopores of the surface to develop high efficiency, long-lasting, high temperature resistant, broad-spectrum antibacterial nano antibacterial powder. This new type of antibacterial material can be widely used in bills, medical and health, chemical building materials, home appliances, functional fibers, plastic products and other industries.

l

As a drug carrier in cancer therapy

As a global public health problem, malignant tumors greatly endanger human health. How to effectively diagnose and treat malignant tumors has become a huge challenge, and the rapid development of nanotechnology has provided new ideas for the effective diagnosis and treatment of cancer. In recent years, mesoporous silica nanoparticles have been used in biomedical fields for their unique physicochemical properties. As a new drug delivery system or tumor imaging contrast agent, they have won more and more attention due to many advantages, for example, their low toxicity and high efficiency.

Mesoporous silica particles have unique structural characteristics and have unique advantages over other nanoparticles. Its advantages are simple synthesis, stable properties, small adverse reactions, large specific surface area, and different types of silica nanoparticles can be produced according to different needs. In addition, mesoporous silica particles are easily surface modified to suit different application needs, such as modifying chitosan on the surface of the particles, and developing a pH-regulated slow release carrier.

l Toxicological study of silica nanoparticles

Although silica nanoparticles have been successfully applied in the biomedical field, the current understanding of the toxic effects of silica nanoparticles is very limited. Since the biological effects of nanoparticles depend to a large extent on their physical and chemical characteristics, the toxic effects of different silica nanoparticles are also different, which poses a great challenge to the toxicological evaluation of silica nanoparticles.

l Supplement: Other applications of silica nanoparticles

Ø Electronic packaging materials.

By fully dispersing the surface-treated nano-silica in the silicone-modified epoxy resin encapsulant matrix, the curing time of the encapsulant can be greatly shortened, and the curing temperature can be lowered to room temperature, so that the sealing performance of the device is remarkable. Increase and increase the life of the device.

Ø Resin composite material.

The nano-silica particles are sufficiently and uniformly dispersed in the resin material to comprehensively improve the properties of the resin-based material.

Ø Plastic.

The use of nano-silica light transmission and small particle size can make the plastic more compact. After adding silica to the polystyrene plastic film, it can improve its transparency, strength, toughness, water resistance and anti-aging property.

Ø Coatings.

It can improve the suspension stability of the coating, poor thixotropy, poor weather resistance, poor scrub resistance, etc., and the bonding strength between the coating film and the wall is greatly improved, the hardness of the coating film is increased, and the surface self-cleaning ability is also improved.

Ø Pigments.

The surface modification treatment of organic pigments by adding nano-SiO2 not only greatly improves the anti-aging performance of the pigment, but also increases the brightness, hue and saturation, and greatly expands the grade and application range of organic pigments.

 

By the way，after knowing the silica nanoparticles, do you want to know about titanium nanoparticles? Browse it fast!

 

References

[1] Zhang Q, Liu F, Nguyen KT, et al., Multifunctional mesoporous silica nanoparticles for cancer -targeted and controlled drug delivery [J]. Adv Fund Mater, 2012, 22: 5144­5156.

[2] L i z , Barnes J C , Bo soy A , et al．Mesoporous silica nanoparticles in biom edical appIications．Chem Soc Rev, 20 12, 41(7): 2590-2605.