| In the first part of the master thesis, we mainly studied the preparation of azithromycin (AZM) capsules by a layer-by-layer self-assembly method and release behavior of AZM capsules. MS/polyelectrolyte (PE) capsules could be prepared by sequential adsorption of oppositely charged polyelectrolyte, also known as layer-by-layer (LbL) self-assembly adsorption onto the surface of mesoporous silica (MS). The MS/PE composite spheres were sequentially put into NaOH and HF/NH4F (pH=5) solution for proper time, then the MS core was removed and hollow PE capsules were obtained. Due to the different dissolution propriety of AZM in water and alcohol, hollow PE capsules were dispersed in AZM alcohol solution of high concentration, and then the capsules were dropwise put in water. After washing by water, AZM capsules, the final product, could be gained. Then we analysed the morphology, FT-IR and XRD of AZM crude drug and AZM capsules. And the results showed that the chemical composition and structure of AZM was unchanged, but compared to AZM crude drug, the particle size of AZM capsules was much more smaller, and the crystal state was changed to amorphous state. Further, the dissolution propriety of AZM crude drug and AZM capsules was compared. The standard curves of AZM aqueous solution and AZM alcohol solution were drew by the way of UV-visible light spectrophotometer, then the dissolution experiments of AZM crude drug and AZM capsules in pH=6.0 and pH=2.0 were carried out for comparing. The results showed that the AZM prepared had an obvious improvement in dissolution propriety contrast to AZM crude drug.In the second part of master thesis, we mainly studied the synthesis of the conjugated polymer based on isoindigo for polymer solar cell. The design and synthesis of conjugated polymers is the critical factor affecting the performance of the solar cells. The bandgap, the HOMO and the LUMO level of the conjugated polymers should be designed deliberately to absorb as much solar energy as possible. Low bandgap conjugated polymers can be obtained by incorporation of electron-donating and electron-withdrawing substituent to form Donor-Acceptor structure in the polymer backbone. Moreover, the solubility, charge mobility and the miscibility with fullerene derivates should be good to ensure the performance of the solar cells. Isoindigo is an interesting structure, and its derivates can be used as the electron-withdrawing moiety in the main structure of the conjugated polymers. At present,7 effective polymers based on isoindigo monomers were synthesized. The molecular weight, optical properties and electrochemical properties of polymers were characterized. And the resulted showed that most of the 7 polymers have proper molecular weight distribution, very good light absorption, and very low optical and electrichemical bandgap. And the current-voltage performances of the solar cells were characterized, and the physical conditions were optimized to achieve the best efficiency for each polymer. At present, the best power conversion efficiency (PCE) of 6.3% was achieved after optimization from one of the 7 polymers.The highest PCEs to date from small molecule based solar cells remain lower than their polymer-based analogs. However, small molecules offer several intrinsic advantages in solution-processable BHJ solar cell. They are easy to crystallize, prepare reproducibly, functionalize and purify. Oligomers are very interesting structures between small monomer and polymer. By studying the properties of oligomers, some rules can be found. In the second part of the thesis, at first we synthesized a series of Q oligomers based on thiophene and quinoxaline moiety in one pot method. To remove the bromide side group and study the affecting of alkyl chain, T and R series of oligomers were synthesized based on Q oligomers. For both T and R oligomers, when the repeating units increase, the conjugation length will increase, leading to a lower bandgap. |
