An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters bet...An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters between the excipients and ibuprofen are used to analyze their compatibility. Both the solubility parameter analysis and the experimental results show that glyceryl behenate is the best among the three excipients. The solid particles disperse well in aqueous phase when the drug loading reaches 10% （relative to lipid only）. Glycerides exhibit marked polymorphism and their rapid rates of crystallization accelerate the formation of metastable crystal modification. The metastable crystal modification characterizes high drug loading capacity but less stability. Increasing the content of lipophilic drug in a lipid matrix facilitates the transformation of excipients to more stable polymorphic forms.展开更多
In this study,a continuous-flow procedure containing four steps has been developed to synthesize Pigment Red 53 and modify its crystal structure.This process avoided the problems of conveying highly insoluble reaction...In this study,a continuous-flow procedure containing four steps has been developed to synthesize Pigment Red 53 and modify its crystal structure.This process avoided the problems of conveying highly insoluble reaction intermediates by removing intermediate operating steps.After optimization,the overall yield of Pigment Red 53:1 reached 97.1%in the total residence time of 80 s by this diazotizationcoupling-laking-crystal transition process.From batch to continuous flow,the purity of products increased from 97.1%to 98.2%and the median diameter of pigment particles decreased from 14μm to 1.9μm.This process achieved a similar crystal transition effect in 18 s as in batch,producingα,δandνcrystals of Pigment Red 53:2 as expected.In conclusion,this continuous-flow procedure displays advantages in both synthesis and crystal transition,indicating another potential use for industrial application.展开更多
In present study, the effect of the solvent annealing temperature on the crystal modifications and the phase transition behavior of the subsequently dried poly（3-octylthiophene） （P3OT） film has been investigated b...In present study, the effect of the solvent annealing temperature on the crystal modifications and the phase transition behavior of the subsequently dried poly（3-octylthiophene） （P3OT） film has been investigated by the combination of DSC, WAXD and FTIR techniques. When chloroform is employed as the solvent, it is unexpectedly found that form I and form II crystal modifications of P3OT could be respectively obtained by room temperature and low temperature annealing. Comparing to the mostly used solvent reported for preparing form II, i.e. carbon disulfide （CS2） which is toxic and corrosive, chloroform is less toxic and corrosive and more suitable for solution processing of P3OT. Therefore, this finding provides an alternative way to obtain form II. By temperature dependent IR spectroscopy, the structural evolution of P3OT during the form II to form I phase transition process has also been studied in detail.展开更多
Photonic crystal heterostructures composed of YbPO4：Er^（3＋） inverse opal and polystyrene opal were prepared via a template-assisted process, which exhibited two photonic band gaps. The microstructure,phase and opt...Photonic crystal heterostructures composed of YbPO4：Er^（3＋） inverse opal and polystyrene opal were prepared via a template-assisted process, which exhibited two photonic band gaps. The microstructure,phase and optical properties of photonic crystal heterostructures were investigated by x-ray diffraction,scanning electron microscopy, fluorescence spectroscopy, absorption spectroscopy, fluorescence lifetime,etc. The upconversion emission suppression caused by single photonic band gap from the following YbPO4：Er^（3＋） inverse opal or the upper opal was observed. The upconversion luminescence was strongly suppressed due to the two photonic band gap overlapping effect caused by the following YbPO4：Er^（3＋） inverse opal or the upper opal. The modified mechanisms of upconversion luminescence were discussed by the upconversion luminescence lifetime of YbPO4：Er^（3＋） photonic crystal heterostructures. The results demonstrated the modified upconversion luminescence is attributed to the photon trapping caused by Bragg reflection of photonic crystal heterostructures.展开更多
The Fenton method is an effective technology for the removal of organic materials from wastewater.In this work,an induced catalyst Fe_(3)O_(4) was synthesized by a hydrothermal method,and the modulation of the chemica...The Fenton method is an effective technology for the removal of organic materials from wastewater.In this work,an induced catalyst Fe_(3)O_(4) was synthesized by a hydrothermal method,and the modulation of the chemical composition of Fe_(3)O_(4) crystals was achieved under the microwave shock method with the same effect as that of calcination treatment.Fe_(3)O_(4) catalyst for the removal of the dye Rhodamine B (Rh B) from polluted wastewater under microwave (MW),H_(2)O_(2) system.The results showed that Fe_(3)O_(4) nanomicrospheres prepared by microwave shock exhibited superior catalytic activity under the conditions of 500 W,0.4 mol/L H_(2)O_(2) and10 mg/L Rh B,and the removal rate of Rh B reached 98.5%after 10 min.The Fe_(3)O_(4) catalysts also exhibited good stability and degradation efficiency.Electron paramagnetic resonance experiments confirmed that·OH plays a major role in the rapid degradation of Rh B.Under microwave action,the catalyst produces electron-hole pairs,in which the holes react with OH-produced by water ionisation to form·OH,and the microwave-treated Fe_(3)O_(4) produces more active species.Fe^(3+)and Fe^(2+)serve as microwave catalytic activity centers and Fenton catalytic activity centers,respectively.This research demonstrates that optimizing the Fe^(2+)/Fe^(3+) ratio significantly enhances the degradation efficiency of Rh B.This study presents novel views regarding the mechanism of microwave synergistic catalyst-induced Fenton.展开更多
Laser-induced modification at 355 nm of deuterated potassium dihydrogen phosphate（DKDP） crystals following exposure to nanosecond（ns） and sub-ns laser irradiation is investigated in order to probe the absorption m...Laser-induced modification at 355 nm of deuterated potassium dihydrogen phosphate（DKDP） crystals following exposure to nanosecond（ns） and sub-ns laser irradiation is investigated in order to probe the absorption mechanism in damage initiation. Laser damage resistance is greatly improved by sub-ns laser conditioning,whereas only a little improvement occurred after ns laser conditioning at the same laser fluence. Moreover, scattering and transmittance variations after the two types of laser conditioning indicate similar reduction of linear absorption. However, by contrast, large differences on nonlinear absorption modification are discovered using Z-scan measurement. This characteristic absorption modification by laser irradiation provides evidence that a nonlinear absorption mechanism plays a key role in damage initiation at 355 nm.展开更多
The polymer on modulating the crystal's habit is an evolving research in pharmaceutical crystallization.This study demonstrates the crystal habit modification of chlorzoxazone(CHZ)by heterogeneous crystallization(...The polymer on modulating the crystal's habit is an evolving research in pharmaceutical crystallization.This study demonstrates the crystal habit modification of chlorzoxazone(CHZ)by heterogeneous crystallization(HC)in the binary solvent acetonitrile-ethanol(A-E(1:1))in the presence of polyvinylpyrrolidine(PVP)at concentrations of 0.50,0.75,and 1.00 wt%.The A-E(1:1)and PVP in HC experiments influenced to change the shape of crystals from needle to plate shape and reduced the crystal size producing a lower aspect ratio(in the range of 1.5-2.3).In the presence of PVP,the CHZ size distribution is 65-78μm which tends to enhance the powder flow-ability of CHZ crystals and as the PVP concentration increases,the nucleation rate decreases.The solubility of size-reduced CHZ crystals at different pH is found to be improved by 1.2-1.4 times.Hence,HC is deemed effective in modifying the physicochemical attributes of CHZ.展开更多
基金Supported by the National Natural Science Foundation of China （No.20536020, No.20476033）, the China Distinguished Young Scientist Fund （No.20225620） and Guangdong Province Science Fund （No.04020121）.
文摘An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters between the excipients and ibuprofen are used to analyze their compatibility. Both the solubility parameter analysis and the experimental results show that glyceryl behenate is the best among the three excipients. The solid particles disperse well in aqueous phase when the drug loading reaches 10% （relative to lipid only）. Glycerides exhibit marked polymorphism and their rapid rates of crystallization accelerate the formation of metastable crystal modification. The metastable crystal modification characterizes high drug loading capacity but less stability. Increasing the content of lipophilic drug in a lipid matrix facilitates the transformation of excipients to more stable polymorphic forms.
基金financial support from Shanghai Municipal Science and Technology Commission (No.21520761100)the Open Project of State Key Laboratory of Chemical Engineering (No. SKL-Ch E-21C07)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Program of Leading Talents (2013)
文摘In this study,a continuous-flow procedure containing four steps has been developed to synthesize Pigment Red 53 and modify its crystal structure.This process avoided the problems of conveying highly insoluble reaction intermediates by removing intermediate operating steps.After optimization,the overall yield of Pigment Red 53:1 reached 97.1%in the total residence time of 80 s by this diazotizationcoupling-laking-crystal transition process.From batch to continuous flow,the purity of products increased from 97.1%to 98.2%and the median diameter of pigment particles decreased from 14μm to 1.9μm.This process achieved a similar crystal transition effect in 18 s as in batch,producingα,δandνcrystals of Pigment Red 53:2 as expected.In conclusion,this continuous-flow procedure displays advantages in both synthesis and crystal transition,indicating another potential use for industrial application.
基金financially supported by the Taishan Mountain Scholar Constructive Engineering Foundation(No.TS20081120)Natural Science Fund for Distinguished Young Scholars of Shandong Province(No.JQ200905)
文摘In present study, the effect of the solvent annealing temperature on the crystal modifications and the phase transition behavior of the subsequently dried poly（3-octylthiophene） （P3OT） film has been investigated by the combination of DSC, WAXD and FTIR techniques. When chloroform is employed as the solvent, it is unexpectedly found that form I and form II crystal modifications of P3OT could be respectively obtained by room temperature and low temperature annealing. Comparing to the mostly used solvent reported for preparing form II, i.e. carbon disulfide （CS2） which is toxic and corrosive, chloroform is less toxic and corrosive and more suitable for solution processing of P3OT. Therefore, this finding provides an alternative way to obtain form II. By temperature dependent IR spectroscopy, the structural evolution of P3OT during the form II to form I phase transition process has also been studied in detail.
基金Project supported by the National Natural Science Foundation of China(11674137)the Applied Basic Research Program of Yunnan Province(2014FB127)+1 种基金Reserve Talents Project of Yunnan Province(2012HB068)Talent Youth Science Foundation of College of Materials Science and Technology,Kunming University of Science and Technology(20140205)
文摘Photonic crystal heterostructures composed of YbPO4：Er^（3＋） inverse opal and polystyrene opal were prepared via a template-assisted process, which exhibited two photonic band gaps. The microstructure,phase and optical properties of photonic crystal heterostructures were investigated by x-ray diffraction,scanning electron microscopy, fluorescence spectroscopy, absorption spectroscopy, fluorescence lifetime,etc. The upconversion emission suppression caused by single photonic band gap from the following YbPO4：Er^（3＋） inverse opal or the upper opal was observed. The upconversion luminescence was strongly suppressed due to the two photonic band gap overlapping effect caused by the following YbPO4：Er^（3＋） inverse opal or the upper opal. The modified mechanisms of upconversion luminescence were discussed by the upconversion luminescence lifetime of YbPO4：Er^（3＋） photonic crystal heterostructures. The results demonstrated the modified upconversion luminescence is attributed to the photon trapping caused by Bragg reflection of photonic crystal heterostructures.
基金supported by Beijing Natural Science Foundation(No.2232062)the Fundamental Research Funds for the Central Universities (No.2652022006)。
文摘The Fenton method is an effective technology for the removal of organic materials from wastewater.In this work,an induced catalyst Fe_(3)O_(4) was synthesized by a hydrothermal method,and the modulation of the chemical composition of Fe_(3)O_(4) crystals was achieved under the microwave shock method with the same effect as that of calcination treatment.Fe_(3)O_(4) catalyst for the removal of the dye Rhodamine B (Rh B) from polluted wastewater under microwave (MW),H_(2)O_(2) system.The results showed that Fe_(3)O_(4) nanomicrospheres prepared by microwave shock exhibited superior catalytic activity under the conditions of 500 W,0.4 mol/L H_(2)O_(2) and10 mg/L Rh B,and the removal rate of Rh B reached 98.5%after 10 min.The Fe_(3)O_(4) catalysts also exhibited good stability and degradation efficiency.Electron paramagnetic resonance experiments confirmed that·OH plays a major role in the rapid degradation of Rh B.Under microwave action,the catalyst produces electron-hole pairs,in which the holes react with OH-produced by water ionisation to form·OH,and the microwave-treated Fe_(3)O_(4) produces more active species.Fe^(3+)and Fe^(2+)serve as microwave catalytic activity centers and Fenton catalytic activity centers,respectively.This research demonstrates that optimizing the Fe^(2+)/Fe^(3+) ratio significantly enhances the degradation efficiency of Rh B.This study presents novel views regarding the mechanism of microwave synergistic catalyst-induced Fenton.
基金supported by the National Natural Science Foundation of China(Nos.61405219 and 11304328)
文摘Laser-induced modification at 355 nm of deuterated potassium dihydrogen phosphate（DKDP） crystals following exposure to nanosecond（ns） and sub-ns laser irradiation is investigated in order to probe the absorption mechanism in damage initiation. Laser damage resistance is greatly improved by sub-ns laser conditioning,whereas only a little improvement occurred after ns laser conditioning at the same laser fluence. Moreover, scattering and transmittance variations after the two types of laser conditioning indicate similar reduction of linear absorption. However, by contrast, large differences on nonlinear absorption modification are discovered using Z-scan measurement. This characteristic absorption modification by laser irradiation provides evidence that a nonlinear absorption mechanism plays a key role in damage initiation at 355 nm.
文摘The polymer on modulating the crystal's habit is an evolving research in pharmaceutical crystallization.This study demonstrates the crystal habit modification of chlorzoxazone(CHZ)by heterogeneous crystallization(HC)in the binary solvent acetonitrile-ethanol(A-E(1:1))in the presence of polyvinylpyrrolidine(PVP)at concentrations of 0.50,0.75,and 1.00 wt%.The A-E(1:1)and PVP in HC experiments influenced to change the shape of crystals from needle to plate shape and reduced the crystal size producing a lower aspect ratio(in the range of 1.5-2.3).In the presence of PVP,the CHZ size distribution is 65-78μm which tends to enhance the powder flow-ability of CHZ crystals and as the PVP concentration increases,the nucleation rate decreases.The solubility of size-reduced CHZ crystals at different pH is found to be improved by 1.2-1.4 times.Hence,HC is deemed effective in modifying the physicochemical attributes of CHZ.
