The existence of electrolytes in aquatic environment on the photocatalytic performance and coagulation of nanodispersed TiO2 hydrosol and the corresponding photocatalytic alteration were investigated by studying catio...The existence of electrolytes in aquatic environment on the photocatalytic performance and coagulation of nanodispersed TiO2 hydrosol and the corresponding photocatalytic alteration were investigated by studying cations(Na^+, K^+, Ca^2+, Mg^2+, and Al^3+).The photocatalysis reactions of nano TiO2 with different dosages of electrolytes were measured by monitoring the degradation of Rhodamine B(Rh B) under ultraviolet A(UV-A) irradiation over time.The results showed that the photocatalytic performance of TiO2 was improved by the presence of Al^3+, while the performance was impaired by the other tested cations.The negative influences of divalent ions on the photocatalytic performance of TiO2 were more significant than monovalent ions.The TiO2 sol dispersed stable at nano scale at low concentration of electrolyte(< 0.01 mol/L) with slight change of pH, and coagulated into micro sizes at high concentration of electrolytes(> 0.1 mol/L) with larger increase or decrease of pH.The positive effects of Al^3+on the photodegradation rate of Rh B might relate to the strong hydrolytic action of Al^3+in aquatic solutions.The photocatalytic processes of TiO2 in the presence of all ions followed the Langmuir-Hinshelwood model, and the reaction kinetic constant was increased with the decrease of pH caused by different cations.These work suggested a new perspective about the relationship between coagulation and photocatalytic performance of TiO2 hydrosols in electrolyte with hydrolysable cations, which demonstrated that TiO2 hydrosols may be suitable as photocatalysts in aquatic environments.展开更多
Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-free polymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of react...Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-free polymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reaction condition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in the hydrosols is 2%. The maximum weight average molecular weight (M-w) of polymer that assures soap-free emulsion conversion into hydrosol is about 1.2 x 10(5)-1.3 x 10(5). The particle transforming process was investigated, and an obvious change of particle diameter and morphology was observed.展开更多
The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy...The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy and transmission electron microscopy. It is found that the freshly prepared hydrosol of Fe2O3 nanoparticles is not stable. The surface pressure increases with the aging time and finally approaches a constant, and the smaller the concentration is, the smaller the surface pressure is stabilized at and the shorter the time the hydrosol reaching stable needs. The surface pressure also increases with compression until collapsed, and the longer the hydrosol is aged, the higher the collapsing pressure is. A uniform and compact film composed of nanoparticles with an average diameter of about 2-3 nm on the air-hydrosol interface is observed by Brewster angle microscope and transmission electron microscope.展开更多
The dispersibility of vermiculite is the key factor that affects the application of vermiculite.In this paper,the milled natural vermiculite was pillared by organic quaternary ammonium salts.Then the pillared vermicul...The dispersibility of vermiculite is the key factor that affects the application of vermiculite.In this paper,the milled natural vermiculite was pillared by organic quaternary ammonium salts.Then the pillared vermiculite was ground and homogenized under the existence of dispersive agent to form a stable vermiculite hydrosol system.Small angle X-ray diffraction(SA-XRD),fourier transform infrared spectroscopy(FTIR),and thermogravimetric analyses(TGA)were used to characterize the structure and thermal property of the vermiculite.The results indicate that the exfoliated vermiculite is successfully obtained.The analyses of laser particle size analyzer,transmission electron microscope(TEM),and Tyndall phenomenon analyzer demonstrate that the vermiculite hydrosol prepared is a stable hydrosol system.展开更多
Antimicrobial resistance is a major global health concern,threatening the effective prevention and treatment of infections caused by microorganisms.These factors boosted the study of safe and green alternatives,with h...Antimicrobial resistance is a major global health concern,threatening the effective prevention and treatment of infections caused by microorganisms.These factors boosted the study of safe and green alternatives,with hydrosols,the by-products of essential oils extraction,emerging as promising natural antimicrobial agents.In this context,four hydrosols obtained from Cupressus leylandii A.B.Jacks&Dallim,Eucalyptus globulus Labill.,Aloysia citrodora Paláu and Melissa officinalis L.were studied.Their chemical composition comprises neral,geranial,1,8-cineole,terpinen-4-ol,and oplopanonyl acetate,compounds with recognised antimicrobial activity.Concerning antimicrobial activity,significant differences were found using different hydrosol concentrations(10-20%v/v)in comparison to a control(without hydrosol),showing the potential of the tested hydrosols to inhibit the microbial growth of Escherichia coli,Staphylococcus aureus,and Candida albicans.A.citrodora hydrosol was the most effective one,inhibiting 90%of E.coli growth and 80%of C.albicans growth,for both hydrosol concentrations(p<0.0001).With hydrosol concentration increase,it was possible to observe an improved antimicrobial activity with significant reductions(p<0.0001).The findings of this work indicate the viability of reusing and valuing the hydrosols,encouraging the development of green applications for different fields(e.g.,food,agriculture,pharmaceuticals,and cosmetics).展开更多
Objective:To demonstrate the anti-inflammatory activity of Brassica napus L.hydrosols(BNH)in lipopolysaccharide(LPS)-stimulated RAW 264.7 cells.Methods:Composition analysis of BNH was conducted via gas chromatography-...Objective:To demonstrate the anti-inflammatory activity of Brassica napus L.hydrosols(BNH)in lipopolysaccharide(LPS)-stimulated RAW 264.7 cells.Methods:Composition analysis of BNH was conducted via gas chromatography-mass spectrometry after BNH were extracted.The nitric oxide(NO)production was measured using the Griess assay.Prostaglandin E2(PGE2)production was evaluated with enzyme-linked immunosorbent assay.The effects of BNH on LPS-induced pro-inflammatory enzymes including inducible nitric oxide synthase(iNOS)and cyclooxygenase-2(COX-2)were evaluated using Western blot analysis.Furthermore,phosphorylation of nuclear factor-kappa B(N F-k B)and nuclear translocation of N F-k B p65 were evaluated with Western blot analysis and immunofluorescence staining,respectively.Results:Compared with LPS-stimulated cells,BNH markedly decreased the generation of NO and PGE_(2)in LPS-stimulated RAW 264.7 cells(P<0.01 or P<0.05).Moreover,BNH inhibited protein levels of iNOS and COX-2(P<0.01).Phosphorylation of NF-k B and nuclear translocation of NF-k B p65 was significantly inhibited by BNH(P<0.01 or P<0.05).Conclusion:The anti-inflammatory activities of BNH were mediated via blockage of the N F-k B signaling pathways in LPS-stimulated RAW 264.7 cells.展开更多
为研究不同品种玫瑰纯露的抗氧化活性,以5种玫瑰花瓣为试验材料,对不同玫瑰纯露的总酚含量、总黄酮含量进行测定并进行抗氧化活性测定。结果显示:丰花一号玫瑰纯露的抗氧化活性较强,紫枝玫瑰纯露次之,滇红玫瑰纯露抗氧化活性相对较弱。...为研究不同品种玫瑰纯露的抗氧化活性,以5种玫瑰花瓣为试验材料,对不同玫瑰纯露的总酚含量、总黄酮含量进行测定并进行抗氧化活性测定。结果显示:丰花一号玫瑰纯露的抗氧化活性较强,紫枝玫瑰纯露次之,滇红玫瑰纯露抗氧化活性相对较弱。丰花一号玫瑰纯露DPPH自由基清除率和ABTS+自由基清除率最高,分别为72.42%和83.85%,铁离子抗氧化能力(ferric ion reducing antioxidant power,FRAP)最高,总黄酮含量也最高;紫枝玫瑰纯露羟自由基清除率最高,为68.65%,总酚含量最高。2种抗氧化物质和4种抗氧化指标之间均存在着正相关关系,总酚含量和总黄酮含量对清除自由基、抗氧化能力有重要影响。展开更多
基金supported by the National Natural Science Foundation of China (Nos.1706222, 51708108 and 51808188)the China Scholarship Council (No.201806090146)+1 种基金China Postdoctoral Science Foundation (No.2018M642151)State Key Laboratory of High Performance Civil Engineering Materials Open Fund (No.2018CEM001).
文摘The existence of electrolytes in aquatic environment on the photocatalytic performance and coagulation of nanodispersed TiO2 hydrosol and the corresponding photocatalytic alteration were investigated by studying cations(Na^+, K^+, Ca^2+, Mg^2+, and Al^3+).The photocatalysis reactions of nano TiO2 with different dosages of electrolytes were measured by monitoring the degradation of Rhodamine B(Rh B) under ultraviolet A(UV-A) irradiation over time.The results showed that the photocatalytic performance of TiO2 was improved by the presence of Al^3+, while the performance was impaired by the other tested cations.The negative influences of divalent ions on the photocatalytic performance of TiO2 were more significant than monovalent ions.The TiO2 sol dispersed stable at nano scale at low concentration of electrolyte(< 0.01 mol/L) with slight change of pH, and coagulated into micro sizes at high concentration of electrolytes(> 0.1 mol/L) with larger increase or decrease of pH.The positive effects of Al^3+on the photodegradation rate of Rh B might relate to the strong hydrolytic action of Al^3+in aquatic solutions.The photocatalytic processes of TiO2 in the presence of all ions followed the Langmuir-Hinshelwood model, and the reaction kinetic constant was increased with the decrease of pH caused by different cations.These work suggested a new perspective about the relationship between coagulation and photocatalytic performance of TiO2 hydrosols in electrolyte with hydrolysable cations, which demonstrated that TiO2 hydrosols may be suitable as photocatalysts in aquatic environments.
文摘Poly(methyl methacrylate/ethyl acrylate/acrylic acid) hydrosols were prepared by employing soap-free polymerization, and (acrylic acid/butyl acrylate) oligomer was used as the polymeric surfactant. The effect of reaction condition on the morphology and particle size of the hydrosols was investigated. The minimum amount of acrylic acid in the hydrosols is 2%. The maximum weight average molecular weight (M-w) of polymer that assures soap-free emulsion conversion into hydrosol is about 1.2 x 10(5)-1.3 x 10(5). The particle transforming process was investigated, and an obvious change of particle diameter and morphology was observed.
基金Funded by the National Natural Science Foundation of China (50672089)the Encouraging Foundation for the Scientific Research of the Excellent Young and Middleaged Scientists in Shandong Province(2006BS04034)
文摘The film forming behavior on the interface between air and hydrosol of Fe2O3 nanoparticles was investigated by the surface pressure-time isotherms, the surface pressure-trough area isotherms, Brewster angle microscopy and transmission electron microscopy. It is found that the freshly prepared hydrosol of Fe2O3 nanoparticles is not stable. The surface pressure increases with the aging time and finally approaches a constant, and the smaller the concentration is, the smaller the surface pressure is stabilized at and the shorter the time the hydrosol reaching stable needs. The surface pressure also increases with compression until collapsed, and the longer the hydrosol is aged, the higher the collapsing pressure is. A uniform and compact film composed of nanoparticles with an average diameter of about 2-3 nm on the air-hydrosol interface is observed by Brewster angle microscope and transmission electron microscope.
基金National High Technology Research and Development Program(863 Program),China(No.2007AA03Z336)Program for New Century Excellent Talents in University,China(No.NCET-07-0174)
文摘The dispersibility of vermiculite is the key factor that affects the application of vermiculite.In this paper,the milled natural vermiculite was pillared by organic quaternary ammonium salts.Then the pillared vermiculite was ground and homogenized under the existence of dispersive agent to form a stable vermiculite hydrosol system.Small angle X-ray diffraction(SA-XRD),fourier transform infrared spectroscopy(FTIR),and thermogravimetric analyses(TGA)were used to characterize the structure and thermal property of the vermiculite.The results indicate that the exfoliated vermiculite is successfully obtained.The analyses of laser particle size analyzer,transmission electron microscope(TEM),and Tyndall phenomenon analyzer demonstrate that the vermiculite hydrosol prepared is a stable hydrosol system.
基金Financial support through national funds FCT/MCTES(PIDDAC)to LSRE-LCM(UIDB/50020/2020 and UIDP/00690/2020)ALiCE(LA/P/0045/2020)+4 种基金CIMO(UIDB/00690/2020 and UIDP/00690/2020)SusTEC(LA/P/0007/2021)FCT for the SFRH/BD/148124/2019 Heloísa Helena Scorsato de Almeida research grantPedro Crugeira thanks OleaChain(NORTE-06-3559-FSE14000188)for his research contractGreenHealth project(Norte-01-0145-FEDER-000042)。
文摘Antimicrobial resistance is a major global health concern,threatening the effective prevention and treatment of infections caused by microorganisms.These factors boosted the study of safe and green alternatives,with hydrosols,the by-products of essential oils extraction,emerging as promising natural antimicrobial agents.In this context,four hydrosols obtained from Cupressus leylandii A.B.Jacks&Dallim,Eucalyptus globulus Labill.,Aloysia citrodora Paláu and Melissa officinalis L.were studied.Their chemical composition comprises neral,geranial,1,8-cineole,terpinen-4-ol,and oplopanonyl acetate,compounds with recognised antimicrobial activity.Concerning antimicrobial activity,significant differences were found using different hydrosol concentrations(10-20%v/v)in comparison to a control(without hydrosol),showing the potential of the tested hydrosols to inhibit the microbial growth of Escherichia coli,Staphylococcus aureus,and Candida albicans.A.citrodora hydrosol was the most effective one,inhibiting 90%of E.coli growth and 80%of C.albicans growth,for both hydrosol concentrations(p<0.0001).With hydrosol concentration increase,it was possible to observe an improved antimicrobial activity with significant reductions(p<0.0001).The findings of this work indicate the viability of reusing and valuing the hydrosols,encouraging the development of green applications for different fields(e.g.,food,agriculture,pharmaceuticals,and cosmetics).
基金Supported by the Korea Basic Science Institute(No.C38915 and C030360)。
文摘Objective:To demonstrate the anti-inflammatory activity of Brassica napus L.hydrosols(BNH)in lipopolysaccharide(LPS)-stimulated RAW 264.7 cells.Methods:Composition analysis of BNH was conducted via gas chromatography-mass spectrometry after BNH were extracted.The nitric oxide(NO)production was measured using the Griess assay.Prostaglandin E2(PGE2)production was evaluated with enzyme-linked immunosorbent assay.The effects of BNH on LPS-induced pro-inflammatory enzymes including inducible nitric oxide synthase(iNOS)and cyclooxygenase-2(COX-2)were evaluated using Western blot analysis.Furthermore,phosphorylation of nuclear factor-kappa B(N F-k B)and nuclear translocation of N F-k B p65 were evaluated with Western blot analysis and immunofluorescence staining,respectively.Results:Compared with LPS-stimulated cells,BNH markedly decreased the generation of NO and PGE_(2)in LPS-stimulated RAW 264.7 cells(P<0.01 or P<0.05).Moreover,BNH inhibited protein levels of iNOS and COX-2(P<0.01).Phosphorylation of NF-k B and nuclear translocation of NF-k B p65 was significantly inhibited by BNH(P<0.01 or P<0.05).Conclusion:The anti-inflammatory activities of BNH were mediated via blockage of the N F-k B signaling pathways in LPS-stimulated RAW 264.7 cells.
文摘为研究不同品种玫瑰纯露的抗氧化活性,以5种玫瑰花瓣为试验材料,对不同玫瑰纯露的总酚含量、总黄酮含量进行测定并进行抗氧化活性测定。结果显示:丰花一号玫瑰纯露的抗氧化活性较强,紫枝玫瑰纯露次之,滇红玫瑰纯露抗氧化活性相对较弱。丰花一号玫瑰纯露DPPH自由基清除率和ABTS+自由基清除率最高,分别为72.42%和83.85%,铁离子抗氧化能力(ferric ion reducing antioxidant power,FRAP)最高,总黄酮含量也最高;紫枝玫瑰纯露羟自由基清除率最高,为68.65%,总酚含量最高。2种抗氧化物质和4种抗氧化指标之间均存在着正相关关系,总酚含量和总黄酮含量对清除自由基、抗氧化能力有重要影响。
