Synthesis,Modification And Properties Of Mesoporous Materials

Mesoporous materials have attracted much attention in the fields of biomedicine and environmental treatment due to their unique properties such as high specific surface area,pore volume and adjustable pore size structure.Although there have been many studies on the pore structure,morphology and particle size regulation of mesoporous silica nanomaterials in the preparation process,it is still a challenging research topic to develop a synthesis route of mesoporous silica nanomaterials with controllable size.Mesoporous carbon has become a research hotspot in the environmental treatment of mesoporous materials because of its high specific surface area,good mechanical strength and chemical stability.Especially,the magnetic mesoporous carbon material can be applied to the adsorption and separation of aqueous dyes owing to its easy separation.In this paper,the synthesis,modification and properties of mesoporous silica and mesoporous carbon were investigated,and the applications of mesoporous materials in drug sustained release and adsorption of water-based dyes were explored.The main contents of this paper are summarized as follows:?1?Mesoporous silica nanomaterials?MSN?were prepared by hydrothermal synthesis.Polyethylene oxide?PEO?and cetyltrimethylammonium bromide?CTAB?were used as double surfactants.The effects of solvent,mass ratio of PEO to CTAB,volume of TEOS and pH value on the morphology of MSN were investigated.The properties were studied by means of TEM,XRD,FT-IR,TGA and N₂adsorption-desorption.The experimental results showed that when the solvent was water,the mass ratio of PEO to CTAB was 2,the volume of TEOS was 4,the pH value of the system was 9,and the crystallization temperature was 110?,the MSN prepared was spherical with a particle size of about 50 nm.In addition,CCK-8 assay exhibited that the synthesis of small-sized MSN had good cytotoxicity.?2?Blue fluorescent carbon dots?CDs?were synthesized by microwave method using citric acid and urea as raw materials.The CDs were dissolved in the cationic surfactant cetylmethylammonium bromide?CTAB?solution by ultrasonication,and then tetraethyl orthosilicate?TEOS?was injected to synthesize blue fluorescent mesoporous silica nanomaterial?MSN-CDs?of mesoporous silica-coated CDs.The effects of different volumes of TEOS on the fluorescence intensity and morphology of MSN-CDs were investigated.The properties of MSN-CDs were characterized by TEM,FT-IR,XPS,N₂ adsorption-desorption and fluorescence spectrophotometer.The results indicated that when the volume of TEOS injected was 75?L,the synthesized MSN-CDs had a regular morphology and the strongest fluorescence intensity.The results of CCK-8 assay revealed that the synthesized blue fluorescent MSN-CDs had good cytotoxicity.?3?Superparamagnetic mesoporous carbon nanocomposites?MMCN?were synthesized by means of polyglycerol?PG?-mediated mesoporous carbon nanoparticles and superparamagnetic iron oxide nanoparticles?SPION?covalently bonded.The properties of MMCN were characterized by TEM,XRD,FT-IR,VSM,XPS,UV-vis and N₂ adsorption-desorption,and used as adsorbents for removing methylene blue?MB?from aqueous solution.The results manifested that the maximum adsorption capacity of MMCM for MB was 250 mg/g,and it could be effectively regenerated and reused by washing with ethanol solution.The adsorption efficiency was still not less than 73%after 6 cycles of adsorption.