Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions w...Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semi-empirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O-OC(O)Ph→PhC(O)O · →Ph · +CO 2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC(O)OO-C(O)Ph→PhC(O)OO · +PhC(O) · → PhC(O) · +O 2 →Ph · +CO+O 2, via which the reaction takes place only in two steps, produces oxygen and PhC(O) · radicals, and the further thermal dissociation of PhC(O) · is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn′t take place in ground state.展开更多
Three crystal architectures, including one organic compound of benzoyl peroxide（Ⅰ） and two clusters of tri-iron（Ⅲ） and bi-cupper（Ⅱ） with benzoic ligands（2 and 3）, were self-assembled by an in situ redox way...Three crystal architectures, including one organic compound of benzoyl peroxide（Ⅰ） and two clusters of tri-iron（Ⅲ） and bi-cupper（Ⅱ） with benzoic ligands（2 and 3）, were self-assembled by an in situ redox way of benzoyl peroxide oxidants reacting with Mo, Fe and Cu powders, respectively. X-ray crystallographic results show that both the asymmetry tri-iron（Ⅲ） cluster and the benzoylperoxide crystal architecture（2 and 1） with complicated 3D networks were constructed by intermolecular hydrogen-bonding interactions. Contrarily, the symmetrical bi-copper（Ⅱ） cluster crystal architecture（3）, only with π-π stacking between paralleled phenyl groups and without any intermolecular hydrogen-bonding interactions, only presented an 1D zigzag chain along the a-axis.展开更多
The effect of benzoyl peroxide （BPO） on polypropylene （PP） degradation in supercritical water was investigated with the aim of developing a process for recycling of waste plastics. A series of experiments with and...The effect of benzoyl peroxide （BPO） on polypropylene （PP） degradation in supercritical water was investigated with the aim of developing a process for recycling of waste plastics. A series of experiments with and without BPO were carried out at temperatures of 653 K and 673 K under pressure about 26 MPa for 30, 75 and 120 min respectively. Products were analyzed by an Ostward-type viscometer, gas chromatography and spectrometry （GC/MS） etc. The results indicated that mean molecular weight of the samples decreased greatly along with the time elapsing or with the temperature increasing, and PP was decomposed to Miphatic and cycloparaftinic hydrocarbons but a few benzenoid hydrocarbons. By comparing the experiments with and without BPO, it was made clear that BPO is an effective additive on PP degradation in supercritical water.展开更多
以甲基丙烯酸甲酯(MMA)为单体、过氧化苯甲酰(BPO)和N,N-二甲基苯胺(DMA)组成的氧化-还原体系为引发剂,采用85℃预聚、24℃后聚和120℃处理工艺进行自由基本体聚合制备了聚甲基丙烯酸甲酯(PMMA)。研究DMA用量、BPO与DMA配比对PMMA透光...以甲基丙烯酸甲酯(MMA)为单体、过氧化苯甲酰(BPO)和N,N-二甲基苯胺(DMA)组成的氧化-还原体系为引发剂,采用85℃预聚、24℃后聚和120℃处理工艺进行自由基本体聚合制备了聚甲基丙烯酸甲酯(PMMA)。研究DMA用量、BPO与DMA配比对PMMA透光率、硬度、强度和热分解温度的影响。研究发现,DMA可明显改善PMMA的力学性能和热学性能,降低其透光率,但不影响透明度。结果表明,当DMA用量3%、BPO与DMA配比0.53∶1时,PMMA硬度为94HD、抗弯强度为66.8 MPa、冲击强度为13.2 k J/m2、初始分解温度为273℃、结束分解温度为404.8℃,380～800 nm的平均透光率为82%以上,综合性能最优。并应用设定的聚合工艺和优化的配方,在低温低压条件下,制备出微米孔结构PMMA,为聚合物微发泡提供了一种新的制备方法。展开更多
To The Editor:Acne vulgaris is a chronic inflammatory skin disease involving the sebaceous glands.It has an incidence of approximately 9.4%,often occurring in adolescents.[1]The disease itself and the scars left after...To The Editor:Acne vulgaris is a chronic inflammatory skin disease involving the sebaceous glands.It has an incidence of approximately 9.4%,often occurring in adolescents.[1]The disease itself and the scars left after treatment can cause psychological stress in adolescents and seriously affect patients’quality of life.[2]At present,skin care products,either alone or in combination with medical drugs,have become important means for treating acne.This single-center,single-blind(clinician-blind),masculine-paralleled,randomized study(Registration number:ChiCTR2100051398)evaluated the efficacy and safety of a cream containing octyl salicylic acid,salicylic acid,linoleic acid,nicotinamide,and piroctone olamine(Duo+,La Roche-Posay,Paris,France)alone and in combination with benzoyl peroxide(BPO,Galderma,Paris,France)for the treatment of mild-to-moderate acne.The research was approved by the Ethics Committee of Shanghai Skin Disease Hospital,China(No.2020-13 ke).All participants provided written informed consent.展开更多
Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects...Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot(CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response.Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.展开更多
The electrochemiluminescence(ECL)properties of many carbon materials have been reported with glassy carbon(GC),Pt,Au or indium tin oxide(ITO)as the working electrode(WE).As one type of carbon materials,GC itself can g...The electrochemiluminescence(ECL)properties of many carbon materials have been reported with glassy carbon(GC),Pt,Au or indium tin oxide(ITO)as the working electrode(WE).As one type of carbon materials,GC itself can generate ECL signal.Some research groups have already noticed the ECL signal from GC WE and reported the results of GC WE with respect to their luminophores.However,comprehensive analyses of ECL properties of GC WE are rare.Herein,the ECL properties of GC WE in organic electrolyte with benzoyl peroxide as the coreactant are reported.Our results are of great importance to distinguish the true ECL data of luminophores from that of GC.展开更多
基金Supported by National NaturalScienceFoundation of China( No.2 97730 0 7) and the NaturalScienceFoundation of Qu-jing Normal College( No.2 0 0 0 0 9)
文摘Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semi-empirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O-OC(O)Ph→PhC(O)O · →Ph · +CO 2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC(O)OO-C(O)Ph→PhC(O)OO · +PhC(O) · → PhC(O) · +O 2 →Ph · +CO+O 2, via which the reaction takes place only in two steps, produces oxygen and PhC(O) · radicals, and the further thermal dissociation of PhC(O) · is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn′t take place in ground state.
基金Supported by the National Natural Science Foundation of China(No.20771073)
文摘Three crystal architectures, including one organic compound of benzoyl peroxide（Ⅰ） and two clusters of tri-iron（Ⅲ） and bi-cupper（Ⅱ） with benzoic ligands（2 and 3）, were self-assembled by an in situ redox way of benzoyl peroxide oxidants reacting with Mo, Fe and Cu powders, respectively. X-ray crystallographic results show that both the asymmetry tri-iron（Ⅲ） cluster and the benzoylperoxide crystal architecture（2 and 1） with complicated 3D networks were constructed by intermolecular hydrogen-bonding interactions. Contrarily, the symmetrical bi-copper（Ⅱ） cluster crystal architecture（3）, only with π-π stacking between paralleled phenyl groups and without any intermolecular hydrogen-bonding interactions, only presented an 1D zigzag chain along the a-axis.
基金Supported by the National Natural Science Foundation of China (No.59972022).
文摘The effect of benzoyl peroxide （BPO） on polypropylene （PP） degradation in supercritical water was investigated with the aim of developing a process for recycling of waste plastics. A series of experiments with and without BPO were carried out at temperatures of 653 K and 673 K under pressure about 26 MPa for 30, 75 and 120 min respectively. Products were analyzed by an Ostward-type viscometer, gas chromatography and spectrometry （GC/MS） etc. The results indicated that mean molecular weight of the samples decreased greatly along with the time elapsing or with the temperature increasing, and PP was decomposed to Miphatic and cycloparaftinic hydrocarbons but a few benzenoid hydrocarbons. By comparing the experiments with and without BPO, it was made clear that BPO is an effective additive on PP degradation in supercritical water.
文摘以甲基丙烯酸甲酯(MMA)为单体、过氧化苯甲酰(BPO)和N,N-二甲基苯胺(DMA)组成的氧化-还原体系为引发剂,采用85℃预聚、24℃后聚和120℃处理工艺进行自由基本体聚合制备了聚甲基丙烯酸甲酯(PMMA)。研究DMA用量、BPO与DMA配比对PMMA透光率、硬度、强度和热分解温度的影响。研究发现,DMA可明显改善PMMA的力学性能和热学性能,降低其透光率,但不影响透明度。结果表明,当DMA用量3%、BPO与DMA配比0.53∶1时,PMMA硬度为94HD、抗弯强度为66.8 MPa、冲击强度为13.2 k J/m2、初始分解温度为273℃、结束分解温度为404.8℃,380～800 nm的平均透光率为82%以上,综合性能最优。并应用设定的聚合工艺和优化的配方,在低温低压条件下,制备出微米孔结构PMMA,为聚合物微发泡提供了一种新的制备方法。
基金Science and Technology Commission of Shanghai Municipality(No. 20Y11905600)Shanghai Municipal Health Commission(No. 20194Y0337)
文摘To The Editor:Acne vulgaris is a chronic inflammatory skin disease involving the sebaceous glands.It has an incidence of approximately 9.4%,often occurring in adolescents.[1]The disease itself and the scars left after treatment can cause psychological stress in adolescents and seriously affect patients’quality of life.[2]At present,skin care products,either alone or in combination with medical drugs,have become important means for treating acne.This single-center,single-blind(clinician-blind),masculine-paralleled,randomized study(Registration number:ChiCTR2100051398)evaluated the efficacy and safety of a cream containing octyl salicylic acid,salicylic acid,linoleic acid,nicotinamide,and piroctone olamine(Duo+,La Roche-Posay,Paris,France)alone and in combination with benzoyl peroxide(BPO,Galderma,Paris,France)for the treatment of mild-to-moderate acne.The research was approved by the Ethics Committee of Shanghai Skin Disease Hospital,China(No.2020-13 ke).All participants provided written informed consent.
基金supported by National Natural Science Foundation of China (Nos. 61805287, 62175262)Natural Science Foundation of Hunan Province,China (No. 2019JJ50824)+1 种基金Fundamental Research Funds for the Central South Universities (Nos. 2020CX021,2020zzts387)Basic Research Foundation of Shenzhen Science and Technology Innovation (No. JCYJ20180307151245919)。
文摘Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot(CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response.Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.
基金support from Natural Sciences and Engineering Research Council Canada(NSERC,DG RGPIN-2013-201697,DG RGPIN-2018-06556 and SPG STPGP-2016-493924)Canada Foundation of Innovation,Ontario Innovation Trust(CFI/OIT,9040)+1 种基金Premier’s Research Excellence Award(PREA,2003)Western University.
文摘The electrochemiluminescence(ECL)properties of many carbon materials have been reported with glassy carbon(GC),Pt,Au or indium tin oxide(ITO)as the working electrode(WE).As one type of carbon materials,GC itself can generate ECL signal.Some research groups have already noticed the ECL signal from GC WE and reported the results of GC WE with respect to their luminophores.However,comprehensive analyses of ECL properties of GC WE are rare.Herein,the ECL properties of GC WE in organic electrolyte with benzoyl peroxide as the coreactant are reported.Our results are of great importance to distinguish the true ECL data of luminophores from that of GC.
