The Preparation Of Smart Nanocontainers Based On Bistable [2]Pseudorotaxanes And Properties For There Controlled Release

Pillar[n]arenes became the third generation supramolecular compounds, followed crown eithers and cyclodextrins, due to the height of the structure symmetry and the characteristics of the more rigid. Their synthesis, derivatization, molecular recognition and application gradually became a hotspot in the field of supramolecular chemistry. Pillar[n]arenes have been reported as macrocyclic host compound to construct supramolecular nanovalve. In the paper, Mechanized silica nanoparticles(MSNs) consisting mesoporous nanoparticles and supramolecular nanovalves have been designed and fabricated. The supramolecular nanovalves based on host-guest complexes were installed over the pore orifices and capable of regulating the flow of encapsulated corrosion inhibitor, Benzotriazole(BTA).The specific works are as follows:(1) Synthesized water-solution pillar[5]arene(WP5) as host macrocyclic supramolecular, and 1,6-(1-hexylbromidepyridine)-hexamethylenediamine (APy-HDA) as guest chain-like molecular with two binding sites was fist synthesized. The binding behaviors of WP5 with two binding sites of APy-HDA in defferent aqueous phosphate buffer solution. The results obtained indicate that the cooperation of C-H...π intreaction and electrostatic attraction between carboxylate headgroup of WPS and ammonium group of HDA in neutral solution forms the [2]pseudorotaxane. After deprotonation of HDA in alkaline solution, WP5 cannot form stable complex with deprotonated HDA stations and shift to APy station due to the vanished electrostatic attraction. (2) designed and fabricated Mechanized silica nanoparticles(MSNs) consisting mesoporous nanoparticles and supramolecular nanovalves, the supramolecular nanovalves based on host-guest complexes of water-solution pillar[5]arene. The construction of functionalized-nanocontainers have been investigated by scanning electron microscope/transmission electron microscope (SEM7TEM), solid state NMR spectra (SS NMR), Fourier Transform Infrared Spectrometer (FTIR), thermogravimetric analysis (TGA), X-ray diffraction assay (XRD), Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses. These results indicate that functionalized-nanocontainers have been designed and fabricated successfully. The release performances of guest molecules at different pH values were monitored by UV-vis spectrophotometer, it turned out when the pH was 7, the releasing 38% BTA melocular from Mechanized silica nanoparticles(MSNs) was about 3600 min. However, at pH>7 and pH<7, about 90%and 70%of BTA molecules wre released within the same time, respectively. It’s suggusted that we preparaed functionalized-nanocontainers have excellently controlled release effects...