Preparation And Structure Research Of Hierarchical Porous Silica Environmental Remediation Materials

Hierarchical porous nanomaterial is a new type of environmental repair materials developed in recent years.Hierarchical porous nanomaterial with large specific surface area,high pore volume and rich pore structure,excellen thermal stability,excellent physical and chemical stability can be used in the adsorption of printing and dyeing wastewater as well as the treatment of heavy metals.In the synthetic process of hierarchical porous nanomaterial,enriching their types and mesoscopic structure,so that their channels develop from one-dimensional to two-dimensional to three-dimensional cubic structures is the most important aspects of the development of such materials.The rich variety of materials provide guarantee for serious environmental problems.This paper studied the synthetic method of a class of environmental repair materials with hierarchical porous structure and analyzed its structure.In the preparation process,through the interaction between the polyelectrolyte and the surfactant,material with hierarchical porous is induced to be synthesized.By adding a non-ionic surfactant,the material with controllable morphology and mesoporous would be obtained,providing experimental methods and data support for the synthesis of developed environmental repair materials.Anionic surfactant?Sar-Na?and non-ionic surfactant?P123?as templating agents,and cationic polyelectrolyte polydiene dimethyl ammonium chloride?PAC?as structure directing agent,the silica materials with three-dimensional cubic Fd-3m symmetrical ordered mesostructure were prepared by co-leading the hydrolysis of the inorganic silicon source.The effects of the amounts of Sar-Na,P123,PAC,TEOS and hydrochloric acid on the morphology and structure of the samples were studied.The results show that the amount of hydrochloric acid exhibited the extraordinary effect on the morphology of the sample,because the amount of hydrochloric acid solution affects the degree of protonation of Sar-Na,controlling the electrostatic force between Sar-Na and PAC to change the binding mode of the template.Mesoporous silica with regular spherical morphology and uniform size were obtained.Mesoporous silica structure were synthesized without adding hydrochloric acid.The diameter of the spheres was about 3?m.Using composite templates to guide inorganic precursors to assemble into mesoporous materials opens up the idea of synthesizing mesoporous silica.The synthesized materials have better adaptability to carry of different sizes.A cationic surfactant cetyl trimethyl ammonium bromide?CTAB?and an anionic polymer polyacrylic acid?PAA?were used to form a composite template,and a phosphorus source and a calcium source were added to synthesize hierarchical porous ordered organisms on the basis of the composite template bioglass?Si O₂-Ca O-P₂O₅?.The effects of p H,ethanol,and phosphorus sources on the morphology and structure of the sample were studied.The results show that when no phosphorus source and calcium source were added to the system,the synthesized sample exhibited three-dimensional ordered Pm-3n mesostructure.Adding the phosphorus source and calcium source,the ordered mesostructure of the sample was destroyed,because the interaction between calcium ions and PAA destroyed the stability of the template emulsion.Changing the content of ethanol would affect the morphology of the sample.When without the addition of ethanol,spherical particles are obtained.As the increase of the amount of ethanol,the spherical morphology of the sample gradually disappears and sticks together.With the addition of a phosphorus source,hierarchical porous structure bioglass with ordered mesostructure Pm-3n and uniform spherical morphology was synthesized.