Preparation Of Terminated Silica Nanotubcs And The Research On Its Properties

Since the selectivity of most drugs in the body is not high, it has the toxicside-effects at non-targeting site. This project designed a capped silica nanotubes, due tothe better biocompatibility and lower toxicity of the silicon, and larger internal cavityvolume, greater hydrophilic surface, and liable functionalization of nanotubes. Thesemi-terminated silica nanotubes were prepared with Al/Al2O3（AAO）template bysol-gel method, and then functionalized by3-aminopropyltriethoxysilane（APTES）. Atthe same time, dialdehyde starch nanoparticles（DASNP）was prepared by methods ofwater-in-oil microemulsion and crosslinkage. After that, the terminated silica nanotubesas drug carrier were prepared by "schiff base" response. The main characterizationmethods include ultraviolet spectrophotometer（UV）, scanning electron microscopy（SEM）, field emission scanning electron microscopy（FESEM）, transmission electronmicroscope（TEM）, Fourier infrared spectromete（rFT-IR）, nuclear magnetic resonancespectrometer（NMR）and laser particle analyzer. The best experiment results are asfollowed:（1）The two-step anodization process was adopted for the preparation of AAOtemplate. Then the semi-terminated silica nanotubes were synthesized with the AAOtemplate by the sol-gel method. The preparation conditions were optimized, and theresults show that the AAO template with about100nm porous diameter was prepared atthe electrolyte concentration of0.4mol/L, the electrolysis temperature of12℃and theanodic oxidation voltage of30V; and the semi-terminated silica nanotubes with80～100nm porous diameter were obtained by the sol-gel method at the drying temperatureof150℃and the drying time of8h under the consecutive vacuum pressure, and thebest preparation condition was determined by controlling the volume ratio of absoluteethanol, tetraethoxysilane（TEOS）and HCl. The volume ratio is50:5:1.（2）TheAPTES functionalized silica nanotubes were prepared at the vacuum, andthe embedding method and curing conditions of functional solution were studied. Theresults show that the optimal volume ratio of APTES, absolute ethanol and acetatebuffer is1:18:1; the AAO template was under consecutive vacuum pressure, and thenimmersed into the functional solution under consecutive vacuum pressure, then in vacuofor20min at120℃.（3）The DASNP with80nm diameters was obtained by HomogeneousExperiment with methods of water-in-oil microemulsion and crosslinkage.Thepreparation conditions were optimized, and the results show that the concentration ofstarch aqueous solution was10%; Voil: VH2Owas20:1; the stirring rate was1200rpm;the concentration of POCl3was0.05%; the reaction temperature was35℃; the reactiontime was3.5h; the reaction pH was3; the NaIO4solution concentration was0.6mol/L.（4）The terminated silica nanotubes as drug carrier were prepared by DASNP andsilica nanotubes with amino.The best preparation condition was determined by stirring5 h in5%ethanol, and then stirring3h in deionized water. At the same time, the reactionmechanism of the terminated silica nanotubes formation is investigated. The resultsshow that the dialdehyde of DASNP and the amino of silica nanotubes may havecombined by "schiff base" response.