The aim of this work is to develop a venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres(HMSMs).HMSMs were innovatively prepared with tetraethyl silicate(TEOS)as the precu...The aim of this work is to develop a venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres(HMSMs).HMSMs were innovatively prepared with tetraethyl silicate(TEOS)as the precursor and volatile n-heptane as a soft template.The obtained HMSMs show a well-defined hollow structure with an average size of 967 nm and pore volume of 0.85 cm^(3)/g,implying it is a potential drug carrier.Subsequently,venlafaxine hydrochloride(VF)was absorbed in the HMSMs with a content of 37.67% or so.The sustained release effect is further measured by the dissolution in-strument at 37℃ and 50 rpm in ultrapure water.The results showed that the HMSMs/VF system shows good sustained release properties compared with sustained release tablets with hydroxypropyl meth-ylcellulose as the main component.This HMSMs sustained release system appears to be a promising candidate for a sustained drug release.展开更多
Fused silica microsphere with a few Eu^3＋ ions on the equator is fabricated. The photon emission sharply modulated by whispering gallery （WG） modes is observed under excitation of 395 nm laser, which is in agreemen...Fused silica microsphere with a few Eu^3＋ ions on the equator is fabricated. The photon emission sharply modulated by whispering gallery （WG） modes is observed under excitation of 395 nm laser, which is in agreement with the prediction in theory. The quality factor of the WG modes in microsphere is estimated larger than 3000 from the emission spectrum, which is limited by our monochrometer. It proves that pumping Eu^3＋ in microsphere cavity in free space is feasible, and this system seems suitable for realizing strong coupling in future quantum computation purposes.展开更多
The morphology regulation of hollow silica microspheres is significant for their properties and applications. In this paper, hollow silica microspheres were formed through the hydrolysis and condensation reaction of t...The morphology regulation of hollow silica microspheres is significant for their properties and applications. In this paper, hollow silica microspheres were formed through the hydrolysis and condensation reaction of tetraethyl orthosilicate(TEOS) at the interface of the emulsion droplet templates composed of liquid paraffin and TEOS, followed by dissolving paraffin with ethanol. The effects of various factors including the emulsifier structure and content, TEOS content, catalyst type, and the ethanol content in the continuous water phase on the particle size, shell thickness and morphology of the prepared hollow silica microspheres were studied in detail. The results show that the diffusion and contact of TEOS and water molecules as well as the hydrolysis condensation reaction of TEOS at the oil-water interface are two critical processes for the synthesis and morphological regulation of hollow silica microspheres. Cationic emulsifier with a hydrophobic chain of appropriate length is the prerequisite for the successful synthesis of hollow silica microspheres. The ethanol content in water phase is the dominant factor to determine the average diameter of hollow microspheres, which can vary from 96 nm to 660 nm with the increase of the volume ratio of alcohol-water from 0 to 0.7. The silica wall thickness varies with the content and the hydrophobic chain length of the emulsifier, TEOS content, and the activity of the catalyst. The component of the soft template will affect the morphology of the silica wall. When the liquid paraffin is replaced by cyclohexane, hollow microspheres with fibrous mesoporous silica wall are fabricated. This work not only enriches the basic theory of interfacial polymerization in the emulsion system, but also provides ideas and methods for expanding the morphology and application of hollow silica microspheres.展开更多
基金supported by the National Natural Science Foundation of China(grant No.22075252).
文摘The aim of this work is to develop a venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres(HMSMs).HMSMs were innovatively prepared with tetraethyl silicate(TEOS)as the precursor and volatile n-heptane as a soft template.The obtained HMSMs show a well-defined hollow structure with an average size of 967 nm and pore volume of 0.85 cm^(3)/g,implying it is a potential drug carrier.Subsequently,venlafaxine hydrochloride(VF)was absorbed in the HMSMs with a content of 37.67% or so.The sustained release effect is further measured by the dissolution in-strument at 37℃ and 50 rpm in ultrapure water.The results showed that the HMSMs/VF system shows good sustained release properties compared with sustained release tablets with hydroxypropyl meth-ylcellulose as the main component.This HMSMs sustained release system appears to be a promising candidate for a sustained drug release.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60537020 and 60121503, the Knowledge Innovation Project of Chinese Academy of Sciences.
文摘Fused silica microsphere with a few Eu^3＋ ions on the equator is fabricated. The photon emission sharply modulated by whispering gallery （WG） modes is observed under excitation of 395 nm laser, which is in agreement with the prediction in theory. The quality factor of the WG modes in microsphere is estimated larger than 3000 from the emission spectrum, which is limited by our monochrometer. It proves that pumping Eu^3＋ in microsphere cavity in free space is feasible, and this system seems suitable for realizing strong coupling in future quantum computation purposes.
基金supported by the National Natural Science Foundation of China (Nos. 51973205, 51773189)Zhuhai Industry-University-Research Institute Collaboration&Basic and Applied Basic Research Project (No. ZH_(2)2017001210059PWC)the Fundamental Research Funds for the Central Universities (Nos.WK9110000066, WK3450000005 and WK3450000006)。
文摘The morphology regulation of hollow silica microspheres is significant for their properties and applications. In this paper, hollow silica microspheres were formed through the hydrolysis and condensation reaction of tetraethyl orthosilicate(TEOS) at the interface of the emulsion droplet templates composed of liquid paraffin and TEOS, followed by dissolving paraffin with ethanol. The effects of various factors including the emulsifier structure and content, TEOS content, catalyst type, and the ethanol content in the continuous water phase on the particle size, shell thickness and morphology of the prepared hollow silica microspheres were studied in detail. The results show that the diffusion and contact of TEOS and water molecules as well as the hydrolysis condensation reaction of TEOS at the oil-water interface are two critical processes for the synthesis and morphological regulation of hollow silica microspheres. Cationic emulsifier with a hydrophobic chain of appropriate length is the prerequisite for the successful synthesis of hollow silica microspheres. The ethanol content in water phase is the dominant factor to determine the average diameter of hollow microspheres, which can vary from 96 nm to 660 nm with the increase of the volume ratio of alcohol-water from 0 to 0.7. The silica wall thickness varies with the content and the hydrophobic chain length of the emulsifier, TEOS content, and the activity of the catalyst. The component of the soft template will affect the morphology of the silica wall. When the liquid paraffin is replaced by cyclohexane, hollow microspheres with fibrous mesoporous silica wall are fabricated. This work not only enriches the basic theory of interfacial polymerization in the emulsion system, but also provides ideas and methods for expanding the morphology and application of hollow silica microspheres.
