Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in br...Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in broad-spectrum(UVA and UVB)sunscreens.It could be partially and selectively acetylated in a simple,fast,and more reliable process.In this work,a composite film was prepared with UV-resistant properties through a casting method.Bio-based cellulose acetate(CA)was employed as a major matrix while nano-acetylated kraft lignin(AL-NPs)was used as filler during synthesizing UV-shielding films loaded with various amounts(1–5 wt.%)of AL-NPs.Kraft lignin was acetylated through a simple and fast microwave-assisted process using acetic acid as a solvent and acetylating agent.The physicochemical and morphological characteristics of the prepared films were evaluated using different methods,including scanning electron microscopy(SEM),Fourier Transform Infrared Spectroscopy(FTIR),X-ray diffraction analysis(XRD),mechanical testing and contact angle measurement.The UV-Vis spectroscopy optical investigation of the prepared films revealed that AL-NPs in the CA matrix showed strong UV absorption.This feature demonstrated the effectiveness of our research in developing UV-resistant bio-based polymer films.Hence,the prepared films can be considered as successful candidates to be applied in packaging applications.展开更多
Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are ...Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are of growing interest for potential use in cosmetics and fragrance industries due to their bioactive properties.Methods:Leaves of C.olitorius cultivated in Egypt were extracted using microwave-assisted hydrodistillation(MAHD)and conventional hydrodistillation(HD).The oils were analyzed by gas chromatography-mass spectrometry(GC-MS)to characterize their chemical profiles.In vitro assays were conducted to evaluate their anti-elastase and anti-collagenase activities,and in silico studies were performed to predict the pharmacokinetic and pharmacodynamic properties of major constituents.Results:GC-MS analysis showed that aldehydes,alkanes,fatty alcohols,fatty acids,and their derivatives were the predominant compound classes in both oils.Notably,oxygenated diterpenes(11.22%)were present exclusively in the MAHD oil,while triterpenoids(16.37%)were found only in the HD oil.The MAHD oil demonstrated stronger In vitro anti-elastase(IC_(50)=42.5μg/mL)and anti-collagenase(IC_(50)=131.5μg/mL)activities compared to the HD oil(IC_(50)=66.7 and 206.8μg/mL,respectively),reflecting an approximate 36.3%improvement in elastase inhibition and 36.4%improvement in collagenase inhibition.In silico docking indicated that the triterpenoidβ-amyrin acetate showed the highest predicted binding affinity for porcine pancreatic elastase(PDB ID:6QEO,ΔG=−8.1 kcal/mol)and collagenase(PDB ID:456C,ΔG=−9.1 kcal/mol)among the major compounds analyzed.Conclusion:These findings demonstrate that MAHD is a greener and more efficient extraction method,yielding oil with enhanced enzyme inhibitory activity compared to conventional HD.The promising anti-elastase and anti-collagenase properties suggest that C.olitorius MAHD oil could serve as a potential candidate for anti-aging cosmetic formulations,following further validation.展开更多
At present,with the increasing application needs of phosphor-converted white light-emitting diode(wLED),the synthetic efficiency and thermal stability of phosphor become urgent problems.Herein,this research reports a ...At present,with the increasing application needs of phosphor-converted white light-emitting diode(wLED),the synthetic efficiency and thermal stability of phosphor become urgent problems.Herein,this research reports a microwave-assisted fast synthesis approach to obtain a Sm^(3+)-activated borotellurate Na_(2)Y_(2)TeO_(4)(BO_(3))_(2)(NYTB)red phosphor with high crystallinity,excellent thermostability,and low chromaticity shift.For the NYTB-based phosphor,in contrast to the conventional solid-state synthesis,the microwave-assisted synthesis method involves lower synthesis temperature and shorter processing time.Additionally,the concentration quenching mechanism was determined.The w-LED device packaged with the studied phosphor exhibits a near-standard white light with proper CCT and high Ra parameters.展开更多
Al_(4)SiC_(4) was synthesized from Al powder, silicon carbide, and graphite by microwave sintering, and characterized by XRD and SEM. Then the synthesized material was added to the magnesia carbon refractory brick to ...Al_(4)SiC_(4) was synthesized from Al powder, silicon carbide, and graphite by microwave sintering, and characterized by XRD and SEM. Then the synthesized material was added to the magnesia carbon refractory brick to study its effect on the oxidation resistance, apparent porosity, bulk density, elastic modulus, and modulus of rupture. It is found that Al_(4)SiC_(4) can be synthesized by microwave sintering at 1 300 ℃ and the addition of Al_(4)SiC_(4)-containing material as an antioxidant can enhance the oxidation resistance of the magnesia carbon refractory brick.展开更多
This paper describes mass-based energy phase-space projection of microwave-assisted synthesis of transition metals (zinc oxide, palladium, silver, platinum, and gold) nanostructures. The projection uses process energy...This paper describes mass-based energy phase-space projection of microwave-assisted synthesis of transition metals (zinc oxide, palladium, silver, platinum, and gold) nanostructures. The projection uses process energy budget (measured in kJ) on the horizontal axes and process density (measured in kJg−1) on the vertical axes. These two axes allow both mass usage efficiency (Environmental-Factor) and energy efficiency to be evaluated for a range of microwave applicator and metal synthesis. The metrics are allied to the: second, sixth and eleventh principle of the twelve principle of Green Chemistry. This analytical approach to microwave synthesis (widely considered as a useful Green Chemistry energy source) allows a quantified dynamic environmental quotient to be given to renewable plant-based biomass associated with the reduction of the metal precursors. Thus allowing a degree of quantification of claimed “eco-friendly” and “sustainable” synthesis with regard to waste production and energy usage.展开更多
In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense （R. Br.） Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction ...In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense （R. Br.） Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power＇s〉solid to liquid ratio＇s〉extraction time＇s〉 ethanol concentration＇s. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows： extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1：17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.展开更多
The property of extraction solution is an important factor influencing the extraction efficiency. In the present work, the effect of the property of solution on extraction of GA was studied, which including the concen...The property of extraction solution is an important factor influencing the extraction efficiency. In the present work, the effect of the property of solution on extraction of GA was studied, which including the concentration of ethanol, ammonia and cation (M+), pH of extraction solution, different kinds of organic solvent etc. The results show that 50%-60%(v/v) ethanol can reach high percentage extraction of GA. If 1% (v/v) ammonia solution was added into 60%(v/v) ethanol, the percentage extraction can be increased from 2.0% to 2.31%. Without ammonia, 50mmol/L [M+] (M+ = K+, NH4+) was added into 60%(v/v) ethanol, percentage extraction of GA can reach about 2.26%. If pH of solution (60% ethanol) was adjust to pH=4.0, it can reach high percentage extraction. If pH of solution (60% ethanol + 50mmol [M+], pH=6.1) was adjust tO PH=4.0, especially M+ is K+ or NH4+, it can reach almost same extraction efficiency as that of 1% ammonia solution + 60% ethanol, and the operation environment can be greatly improved.展开更多
An optimized approach for the synthesis of N^1-ethoxymethyl-substituted cyclic inosine diphosphoribose（cIDPRE）,an analogue of cyclic adenosine diphosphoribose（cADPR）,has been developed via microwave-assisted intra...An optimized approach for the synthesis of N^1-ethoxymethyl-substituted cyclic inosine diphosphoribose（cIDPRE）,an analogue of cyclic adenosine diphosphoribose（cADPR）,has been developed via microwave-assisted intramolecular cyclization. The target compound has been successfully obtained through N^1-substitution,phosphorylation,cyclization and deprotection.By using this method,8-amino and bromo-substituted cIDPRE analogues were successfully obtained in good yield.The new approach has greatly shortened the synthetic route and enhanced the overall efficiency.展开更多
Microwave heating contributes to coal fracturing and gas desorption. However, problems of low penetration depth, local overheating and fracture closure exist. Coal demineralisation by acids has advantages in coal unbl...Microwave heating contributes to coal fracturing and gas desorption. However, problems of low penetration depth, local overheating and fracture closure exist. Coal demineralisation by acids has advantages in coal unblocking and permeability improvement, while it is difficult for acid to enter microcracks.Microwave-asisted acidification may offer an alternative. In this work, XRD,^(1)H-NMR, and SEM were used to evaluate the effect of microwave-assisted acidification on the microstructure of coal. Results show that kaolinite, calcite, and dolomite can be dissolved by acid. After microwave irradiation, the graphitization of microcrystalline structure of carbon improves. Microwave-assisted acidification erodes minerals in coal and enhances the graphitization degree of microcrystalline structure. Compared to individual microwave irradiation or acidification, the pore volume and pore connectivity can be greatly enhanced by microwave-assisted acidification. The NMR permeability of coal increased by 28.05%. This study demonstrates the potential of microwave-assisted acidification for coalbed methane recovery.展开更多
A highly active ZrO x /ZnO catalyst for microwave-assisted photocatalytic （MW/PC） degradation of endocrine disruptor dimethyl phthalate （DMP） has been prepared via cetyltrimethylammonium assisted hydrothermal meth...A highly active ZrO x /ZnO catalyst for microwave-assisted photocatalytic （MW/PC） degradation of endocrine disruptor dimethyl phthalate （DMP） has been prepared via cetyltrimethylammonium assisted hydrothermal method. The ZrO x /ZnO was characterized by XPS, XRD, UV-Vis, BET and SEM techniques. The XPS result showed that Zr oxides with different valences （＋2, ＋3, ＋4） co-existed in ZrO x /ZnO. By using the ZrO x /ZnO （0.1 g）, the TOC removal efficiency of DMP （100 mL of 50 mg/L） was 88% after 30 min reaction, which was about 15% higher than P25 TiO 2 . It was found that the removal process of DMP by MW/PC followed pseudo first-order kinetics in all cases, and ZrO x /ZnO significantly accelerated the degradation of DMP. The degradation half-life time of DMP was shortened 45% compared with P25 TiO 2 . A possible catalytic mechanism was proposed based on microwave response and interfacial charge transfer. ZrO x /ZnO could be reused for six times without obvious decrease in catalytic activity. The study offers new insights into designing highly efficient catalysts for MW/PC process and is applicable for MW/PC environmental remediation.展开更多
The microwave-assisted method was used to extract polysaccharides from solanum nigrum. The optimum experimental parameters, mechanism of the extraction and the effect of microwave-assisted extraction process on the st...The microwave-assisted method was used to extract polysaccharides from solanum nigrum. The optimum experimental parameters, mechanism of the extraction and the effect of microwave-assisted extraction process on the structures of polysaccharides were investigated. The extract was analyzed by the modified phenol-sulfuric acid method at 490nm. The optimum experimental parameters were obtained by orthogonal experiments as follows: extraction time 15min, microwave radiation power 455W and the process ratio of materials mass to solvent volume 1∶20. The results show that compared with the conventional reflux extraction, the microwave-assisted extraction has a higher yield in shorter time, with no effect on the finally obtained polysaccharides as seen from the FT-IR spectra. The scanning electron microscopy images reveal that the mechanism of the extraction is related to the structural changes of the plant cells in different extracting conditions.展开更多
Microwave-assisted extraction （MAE） of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. ...Microwave-assisted extraction （MAE） of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. It was concluded that two doses of intermittent microwave power radiation, 300 W each for 4 rain, were needed for extraction. The mass ratio of solvent to material was 8：1 and the alcohol mass fraction was 80%. The extracted liquor was then concentrated under vacuum and degreased with petroleum ether. The yield of total isofiavones was about 8.8% and the contents of tectoridin and iridin were 67.6% and 16.3% respectively. Compared with direct-heating extraction （DHE）, MAE may shorten extracting duration, reduce solvent consumption, and improve yield and purity of isoflavones from Belamcanda chinensis.展开更多
A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste resid...A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste residues. Microwave pyrolysis was found to efficiently deliver comparable evolution of bio-gases in the system as compared with conventional pyrolysis at significantly reduced temperatures （120-180 ℃vs 250-400 ℃）. The gas obtained from microwave-assisted pyrolysis was found to contain CO2, CH4 and CO as major components as well展开更多
A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides...A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.展开更多
Hydrothermal methods are widely used in chemical synthesis of target products with specific morphology and nanostructure.Those methods are very efficient for the preparation of well-controlled structures but the react...Hydrothermal methods are widely used in chemical synthesis of target products with specific morphology and nanostructure.Those methods are very efficient for the preparation of well-controlled structures but the reaction time is usually long.The assistance of microwave makes the reaction system heat up faster,more uniformly and reactions are accelerated,it also can be utilized to change the morphology or structure of materials,which improves the physic-chemical properties of synthesized products and influences its gas-sensing performance.Copper oxide(CuO)is widely applied in semiconductor gas sensors because of its good reactivity and stability.This review article briefly introduces the principle,mechanism and recent development of CuO nanostructures obtained by microwave-as sis ted hydrothermal synthesis(MWHS)process.It also discussed the relation between endopathic factors of material and its gas-sensitive performance.The technical challenges and prospective solutions for highperformance CuO-based gas-sensitive materials with unique nanostructure are proposed.It is pointed out that the hierarchical CuO-based nanostructures and their composite materials prepared by MWHS process are efficacious methods to improve the gas-sensitive performance of the materials.On the basis of the morphology,the materials are divided into nanorods,nanoflowers,nanosheets,nanospheres and other nanostructures.The influence of microwave parameters on the properties of synthetic products is analyzed.The influence followed by metal element loading on the structure and properties of CuO-based materials by MWHS process is further discussed.Then this review summarizes the research progress of graphene-CuO and metal oxide-CuO composites prepared by MWHS process in recent years.展开更多
Microwave-assisted extraction (MAE) for active ingredients in Ciwujia was studied by using ethanol as the extractant. Comparing MAE with conventional methods, the former can save the extracting time and increase the c...Microwave-assisted extraction (MAE) for active ingredients in Ciwujia was studied by using ethanol as the extractant. Comparing MAE with conventional methods, the former can save the extracting time and increase the content of the active ingredients in product. As to the operation in MAE, the continuous radiation process is more convenient for the extraction for traditional Chinese medicine than the intermittent radiation process. Optimized by uniform design, MAE was proved to be an effective and novel process for extracting active ingredients in Ciwujia. The optimized MAE conditions are as follows: the microwave power is 510W, the radiation time 30min, the alcohol concentration at 80%, the ratio of solvent to solid material being 5:1, the soaking time 0.5h, and the herbal particle size is (520±19)μm.展开更多
Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction(SMOBE). The...Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction(SMOBE). The third procedure was microwave resonant cavity dynamic extraction(MRCDE). The results obtained by the three microwave-assisted extraction procedures were compared with those obtained by using traditional Soxhlet extraction. The results indicate that the MAE not only took a shorter time, but also simplified the procedure, and made the extraction a higher yield. At the same time the results obtained by the three MAE procedures were also compared with each other.展开更多
In this work,a fast and efficient microwave-assisted extraction(MAE) method was developed to extract main bioactive alkaloids from lotus plumue.To optimize MAE conditions,three main factors were selected using univari...In this work,a fast and efficient microwave-assisted extraction(MAE) method was developed to extract main bioactive alkaloids from lotus plumue.To optimize MAE conditions,three main factors were selected using univariate approach experiments,and then central composite design(CCD).The optimal extraction conditions were as follows:methanol concentration of 65%,microwave power of 200 W,and extraction time of 260 s.A high performance liquid chromatography–diode array detector(HPLC–DAD) method was established to quantitatively analyze these phytochemicals in different lotus plumule samples and in different part of lotus.Chromatographic separation was carried out on an Agilent Zorbax Extend-C_(18) column(4.6 mm×150 mm,3.5 μm).Gradient elution was applied with the mobile phase constituted with 0.1% triethylamine in water(A)and acetonitrile(B):40%-70% B at 0-8 min,70%-100% B at 8–9 min,100% B for 2 min,and then equilibrated with 40% B for 2 min.展开更多
The feasibility of emploving non-ionic surfactant （Triton X-100） as an alternative and effective solventfor the microwave-assisted extraction of glycyrrhizic acid （GA） and liquiritin （LQ） from licorice root was ...The feasibility of emploving non-ionic surfactant （Triton X-100） as an alternative and effective solventfor the microwave-assisted extraction of glycyrrhizic acid （GA） and liquiritin （LQ） from licorice root was studied.The optimal extraction parameters based on the microwave-assisted micellar extraction technique were determined.Under the optimal conditions, i.e. 5% （by volume） Triton X-100, microwave-assisted extraction for 3--5min at 373K, the percentage extraction of active ingredients reached the highest value. The preconcentration tactor for GA and L＇Q （about 13.5） and the extraction efficiency for these two ingredients approached 100% showed the coupling of microwave-assisted extraction and cloud-point extraction could be employed as a new and. effective techniquefor the rapid extraction and preconcentration of pharrnacologically active ingredients from medicinal plants SUCh aslicorice root without disturbing chromatographic analysis.展开更多
The construction of a homojunction is an effective approach for addressing issues such as slow charge separation and charge-transfer kinetics in photoanodes.In the present work,we designed a gradient Si-and Ti-doped F...The construction of a homojunction is an effective approach for addressing issues such as slow charge separation and charge-transfer kinetics in photoanodes.In the present work,we designed a gradient Si-and Ti-doped Fe_(2)O_(3) homojunction photoanode to improve the photoelectrochemical(PEC)performance of a Ti-doped Fe_(2)O_(3) photoanode.Ti-FeOOH nanocorals were synthesized using a hydrothermal process,and Si-FeOOH was grown on Ti-FeOOH nanocorals using a rapid and facile microwaveassisted(MW)technique.By varying the MW irradiation time,the thickness of the Si/Ti:Fe_(2)O_(3) photoanode was adjusted and an optimized 3-Si/Ti:Fe_(2)O_(3) photoelectrode was achieved with a significantly enhanced photocurrent density(1.37 mA cm^(-2) at 1.23 V vs.RHE)and a cathodic shift of the onset potential(150 mV)compared with that of bare Ti-Fe_(2)O_(3).This enhanced PEC performance can be ascribed to homojunction formation and Si gradient doping.The Si dopant increased the donor concentration and the formation of a homojunction improved the intrinsic built-in electric field,thereby promoting charge separation and charge transfer.Furthermore,the as-formed homojunction passivated the surfacetrapping states,consequently improving the charge transfer efficiency(60%at 1.23 VRHE)at the photoanode/electrolyte interface.These findings could pave the way for the microwave-assisted fabrication of diverse efficient homojunction photoanodes for PEC water splitting applications.展开更多
文摘Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in broad-spectrum(UVA and UVB)sunscreens.It could be partially and selectively acetylated in a simple,fast,and more reliable process.In this work,a composite film was prepared with UV-resistant properties through a casting method.Bio-based cellulose acetate(CA)was employed as a major matrix while nano-acetylated kraft lignin(AL-NPs)was used as filler during synthesizing UV-shielding films loaded with various amounts(1–5 wt.%)of AL-NPs.Kraft lignin was acetylated through a simple and fast microwave-assisted process using acetic acid as a solvent and acetylating agent.The physicochemical and morphological characteristics of the prepared films were evaluated using different methods,including scanning electron microscopy(SEM),Fourier Transform Infrared Spectroscopy(FTIR),X-ray diffraction analysis(XRD),mechanical testing and contact angle measurement.The UV-Vis spectroscopy optical investigation of the prepared films revealed that AL-NPs in the CA matrix showed strong UV absorption.This feature demonstrated the effectiveness of our research in developing UV-resistant bio-based polymer films.Hence,the prepared films can be considered as successful candidates to be applied in packaging applications.
基金Egyptian Science and Technology and Innovation Fund(STIFA)for the support of the study through grant No.46667 entitled“Sustainability of Lab Capacities of the Center of Drug Discovery Research and Development”.
文摘Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are of growing interest for potential use in cosmetics and fragrance industries due to their bioactive properties.Methods:Leaves of C.olitorius cultivated in Egypt were extracted using microwave-assisted hydrodistillation(MAHD)and conventional hydrodistillation(HD).The oils were analyzed by gas chromatography-mass spectrometry(GC-MS)to characterize their chemical profiles.In vitro assays were conducted to evaluate their anti-elastase and anti-collagenase activities,and in silico studies were performed to predict the pharmacokinetic and pharmacodynamic properties of major constituents.Results:GC-MS analysis showed that aldehydes,alkanes,fatty alcohols,fatty acids,and their derivatives were the predominant compound classes in both oils.Notably,oxygenated diterpenes(11.22%)were present exclusively in the MAHD oil,while triterpenoids(16.37%)were found only in the HD oil.The MAHD oil demonstrated stronger In vitro anti-elastase(IC_(50)=42.5μg/mL)and anti-collagenase(IC_(50)=131.5μg/mL)activities compared to the HD oil(IC_(50)=66.7 and 206.8μg/mL,respectively),reflecting an approximate 36.3%improvement in elastase inhibition and 36.4%improvement in collagenase inhibition.In silico docking indicated that the triterpenoidβ-amyrin acetate showed the highest predicted binding affinity for porcine pancreatic elastase(PDB ID:6QEO,ΔG=−8.1 kcal/mol)and collagenase(PDB ID:456C,ΔG=−9.1 kcal/mol)among the major compounds analyzed.Conclusion:These findings demonstrate that MAHD is a greener and more efficient extraction method,yielding oil with enhanced enzyme inhibitory activity compared to conventional HD.The promising anti-elastase and anti-collagenase properties suggest that C.olitorius MAHD oil could serve as a potential candidate for anti-aging cosmetic formulations,following further validation.
基金Project supported by the National Natural Science Foundation of China(22165031,21761034)NationalUndergraduate Innovation and Entrepreneurship Foundation(202210673034)Scientific Research Foundation of Education Departmentof Yunnan province(2022Y001)。
文摘At present,with the increasing application needs of phosphor-converted white light-emitting diode(wLED),the synthetic efficiency and thermal stability of phosphor become urgent problems.Herein,this research reports a microwave-assisted fast synthesis approach to obtain a Sm^(3+)-activated borotellurate Na_(2)Y_(2)TeO_(4)(BO_(3))_(2)(NYTB)red phosphor with high crystallinity,excellent thermostability,and low chromaticity shift.For the NYTB-based phosphor,in contrast to the conventional solid-state synthesis,the microwave-assisted synthesis method involves lower synthesis temperature and shorter processing time.Additionally,the concentration quenching mechanism was determined.The w-LED device packaged with the studied phosphor exhibits a near-standard white light with proper CCT and high Ra parameters.
基金This work was funded by Luoyang Major Science and Technology Innovation Project(2301009A)Henan Province Key Research and Development Project(231111230200)。
文摘Al_(4)SiC_(4) was synthesized from Al powder, silicon carbide, and graphite by microwave sintering, and characterized by XRD and SEM. Then the synthesized material was added to the magnesia carbon refractory brick to study its effect on the oxidation resistance, apparent porosity, bulk density, elastic modulus, and modulus of rupture. It is found that Al_(4)SiC_(4) can be synthesized by microwave sintering at 1 300 ℃ and the addition of Al_(4)SiC_(4)-containing material as an antioxidant can enhance the oxidation resistance of the magnesia carbon refractory brick.
文摘This paper describes mass-based energy phase-space projection of microwave-assisted synthesis of transition metals (zinc oxide, palladium, silver, platinum, and gold) nanostructures. The projection uses process energy budget (measured in kJ) on the horizontal axes and process density (measured in kJg−1) on the vertical axes. These two axes allow both mass usage efficiency (Environmental-Factor) and energy efficiency to be evaluated for a range of microwave applicator and metal synthesis. The metrics are allied to the: second, sixth and eleventh principle of the twelve principle of Green Chemistry. This analytical approach to microwave synthesis (widely considered as a useful Green Chemistry energy source) allows a quantified dynamic environmental quotient to be given to renewable plant-based biomass associated with the reduction of the metal precursors. Thus allowing a degree of quantification of claimed “eco-friendly” and “sustainable” synthesis with regard to waste production and energy usage.
基金Supported by Open Funds for Innovation Platforms of Colleges and Universities in Hunan Province(15K066)National College Students'Innovative Entrepreneuria Training Program(201510553003)Research Study and Innovative Experiment Plan Project for College Students in Hunan Province(2015-499)~~
文摘In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense （R. Br.） Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power＇s〉solid to liquid ratio＇s〉extraction time＇s〉 ethanol concentration＇s. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows： extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1：17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.
基金Supported by the National Natural Science Foundation of China(No.29836130).
文摘The property of extraction solution is an important factor influencing the extraction efficiency. In the present work, the effect of the property of solution on extraction of GA was studied, which including the concentration of ethanol, ammonia and cation (M+), pH of extraction solution, different kinds of organic solvent etc. The results show that 50%-60%(v/v) ethanol can reach high percentage extraction of GA. If 1% (v/v) ammonia solution was added into 60%(v/v) ethanol, the percentage extraction can be increased from 2.0% to 2.31%. Without ammonia, 50mmol/L [M+] (M+ = K+, NH4+) was added into 60%(v/v) ethanol, percentage extraction of GA can reach about 2.26%. If pH of solution (60% ethanol) was adjust to pH=4.0, it can reach high percentage extraction. If pH of solution (60% ethanol + 50mmol [M+], pH=6.1) was adjust tO PH=4.0, especially M+ is K+ or NH4+, it can reach almost same extraction efficiency as that of 1% ammonia solution + 60% ethanol, and the operation environment can be greatly improved.
基金National Natural Science Foundation of China (Grant No.20910094) Ministry of Education of China(Grant No.200800010078)
文摘An optimized approach for the synthesis of N^1-ethoxymethyl-substituted cyclic inosine diphosphoribose（cIDPRE）,an analogue of cyclic adenosine diphosphoribose（cADPR）,has been developed via microwave-assisted intramolecular cyclization. The target compound has been successfully obtained through N^1-substitution,phosphorylation,cyclization and deprotection.By using this method,8-amino and bromo-substituted cIDPRE analogues were successfully obtained in good yield.The new approach has greatly shortened the synthetic route and enhanced the overall efficiency.
基金supported by the National Natural Science Foundation of China (Nos. 52274195, 52274196, 51904103, and 52174180)the Science and Technology Innovation Program of Hunan Province (No. 2022RC1178)+1 种基金Hunan Provincial Natural Science Foundation of China (Nos. 2022JJ20024, and 2021JJ30254)Scientific Research Foundation of Hunan Provincial Education Department (No. 21B0465)。
文摘Microwave heating contributes to coal fracturing and gas desorption. However, problems of low penetration depth, local overheating and fracture closure exist. Coal demineralisation by acids has advantages in coal unblocking and permeability improvement, while it is difficult for acid to enter microcracks.Microwave-asisted acidification may offer an alternative. In this work, XRD,^(1)H-NMR, and SEM were used to evaluate the effect of microwave-assisted acidification on the microstructure of coal. Results show that kaolinite, calcite, and dolomite can be dissolved by acid. After microwave irradiation, the graphitization of microcrystalline structure of carbon improves. Microwave-assisted acidification erodes minerals in coal and enhances the graphitization degree of microcrystalline structure. Compared to individual microwave irradiation or acidification, the pore volume and pore connectivity can be greatly enhanced by microwave-assisted acidification. The NMR permeability of coal increased by 28.05%. This study demonstrates the potential of microwave-assisted acidification for coalbed methane recovery.
基金supported by the National Natural Science Foundation of China(No.50678045,50821002)
文摘A highly active ZrO x /ZnO catalyst for microwave-assisted photocatalytic （MW/PC） degradation of endocrine disruptor dimethyl phthalate （DMP） has been prepared via cetyltrimethylammonium assisted hydrothermal method. The ZrO x /ZnO was characterized by XPS, XRD, UV-Vis, BET and SEM techniques. The XPS result showed that Zr oxides with different valences （＋2, ＋3, ＋4） co-existed in ZrO x /ZnO. By using the ZrO x /ZnO （0.1 g）, the TOC removal efficiency of DMP （100 mL of 50 mg/L） was 88% after 30 min reaction, which was about 15% higher than P25 TiO 2 . It was found that the removal process of DMP by MW/PC followed pseudo first-order kinetics in all cases, and ZrO x /ZnO significantly accelerated the degradation of DMP. The degradation half-life time of DMP was shortened 45% compared with P25 TiO 2 . A possible catalytic mechanism was proposed based on microwave response and interfacial charge transfer. ZrO x /ZnO could be reused for six times without obvious decrease in catalytic activity. The study offers new insights into designing highly efficient catalysts for MW/PC process and is applicable for MW/PC environmental remediation.
文摘The microwave-assisted method was used to extract polysaccharides from solanum nigrum. The optimum experimental parameters, mechanism of the extraction and the effect of microwave-assisted extraction process on the structures of polysaccharides were investigated. The extract was analyzed by the modified phenol-sulfuric acid method at 490nm. The optimum experimental parameters were obtained by orthogonal experiments as follows: extraction time 15min, microwave radiation power 455W and the process ratio of materials mass to solvent volume 1∶20. The results show that compared with the conventional reflux extraction, the microwave-assisted extraction has a higher yield in shorter time, with no effect on the finally obtained polysaccharides as seen from the FT-IR spectra. The scanning electron microscopy images reveal that the mechanism of the extraction is related to the structural changes of the plant cells in different extracting conditions.
文摘Microwave-assisted extraction （MAE） of isoflavones from Belamcanda chinensis was studied using ethanol as the solvent. The single factor experiment and the orthogonal method were used to optimize the MAE condition. It was concluded that two doses of intermittent microwave power radiation, 300 W each for 4 rain, were needed for extraction. The mass ratio of solvent to material was 8：1 and the alcohol mass fraction was 80%. The extracted liquor was then concentrated under vacuum and degreased with petroleum ether. The yield of total isofiavones was about 8.8% and the contents of tectoridin and iridin were 67.6% and 16.3% respectively. Compared with direct-heating extraction （DHE）, MAE may shorten extracting duration, reduce solvent consumption, and improve yield and purity of isoflavones from Belamcanda chinensis.
基金supported by the Gobierno de Espaa for the Provision of a Ramon y Cajal Contract (RYC-2009-04199),Projects P10 FQM-6711(Consejeria de Ciencia e Innovacion,Junta de Andalucia) and CTQ2011 28954-C02-02 (MICINN)
文摘A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste residues. Microwave pyrolysis was found to efficiently deliver comparable evolution of bio-gases in the system as compared with conventional pyrolysis at significantly reduced temperatures （120-180 ℃vs 250-400 ℃）. The gas obtained from microwave-assisted pyrolysis was found to contain CO2, CH4 and CO as major components as well
基金The study was financially supported by the National Science and Technology Support Program of China(Grant No.2013BAD16B08).
文摘A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.
基金financially supported by the National Key Research and Development Program of China(No.2017YFE0115900)the Natural Science Foundation of China(No.51872254)Yangzhou City-Yangzhou University Cooperation Foundation(No.YZU201801)。
文摘Hydrothermal methods are widely used in chemical synthesis of target products with specific morphology and nanostructure.Those methods are very efficient for the preparation of well-controlled structures but the reaction time is usually long.The assistance of microwave makes the reaction system heat up faster,more uniformly and reactions are accelerated,it also can be utilized to change the morphology or structure of materials,which improves the physic-chemical properties of synthesized products and influences its gas-sensing performance.Copper oxide(CuO)is widely applied in semiconductor gas sensors because of its good reactivity and stability.This review article briefly introduces the principle,mechanism and recent development of CuO nanostructures obtained by microwave-as sis ted hydrothermal synthesis(MWHS)process.It also discussed the relation between endopathic factors of material and its gas-sensitive performance.The technical challenges and prospective solutions for highperformance CuO-based gas-sensitive materials with unique nanostructure are proposed.It is pointed out that the hierarchical CuO-based nanostructures and their composite materials prepared by MWHS process are efficacious methods to improve the gas-sensitive performance of the materials.On the basis of the morphology,the materials are divided into nanorods,nanoflowers,nanosheets,nanospheres and other nanostructures.The influence of microwave parameters on the properties of synthetic products is analyzed.The influence followed by metal element loading on the structure and properties of CuO-based materials by MWHS process is further discussed.Then this review summarizes the research progress of graphene-CuO and metal oxide-CuO composites prepared by MWHS process in recent years.
文摘Microwave-assisted extraction (MAE) for active ingredients in Ciwujia was studied by using ethanol as the extractant. Comparing MAE with conventional methods, the former can save the extracting time and increase the content of the active ingredients in product. As to the operation in MAE, the continuous radiation process is more convenient for the extraction for traditional Chinese medicine than the intermittent radiation process. Optimized by uniform design, MAE was proved to be an effective and novel process for extracting active ingredients in Ciwujia. The optimized MAE conditions are as follows: the microwave power is 510W, the radiation time 30min, the alcohol concentration at 80%, the ratio of solvent to solid material being 5:1, the soaking time 0.5h, and the herbal particle size is (520±19)μm.
基金the Science and Technology Developing Fellowship Program(No.2 0 0 30 5 5 1- 7) by Jilin Province
文摘Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction(SMOBE). The third procedure was microwave resonant cavity dynamic extraction(MRCDE). The results obtained by the three microwave-assisted extraction procedures were compared with those obtained by using traditional Soxhlet extraction. The results indicate that the MAE not only took a shorter time, but also simplified the procedure, and made the extraction a higher yield. At the same time the results obtained by the three MAE procedures were also compared with each other.
基金partially supported by grants from the Science and Technology Development Fund of Macao(FDCT059/2011/A3)the University of Macao(MYRG085 to Jing Zhao and MYRG201400041 to LSP,respectively)
文摘In this work,a fast and efficient microwave-assisted extraction(MAE) method was developed to extract main bioactive alkaloids from lotus plumue.To optimize MAE conditions,three main factors were selected using univariate approach experiments,and then central composite design(CCD).The optimal extraction conditions were as follows:methanol concentration of 65%,microwave power of 200 W,and extraction time of 260 s.A high performance liquid chromatography–diode array detector(HPLC–DAD) method was established to quantitatively analyze these phytochemicals in different lotus plumule samples and in different part of lotus.Chromatographic separation was carried out on an Agilent Zorbax Extend-C_(18) column(4.6 mm×150 mm,3.5 μm).Gradient elution was applied with the mobile phase constituted with 0.1% triethylamine in water(A)and acetonitrile(B):40%-70% B at 0-8 min,70%-100% B at 8–9 min,100% B for 2 min,and then equilibrated with 40% B for 2 min.
基金Supported by the National Science Fund for Creative Research Groups （No.20221603）, the National Natural Science Foundation of China Key Project （No.20490200） and PetroChina.
文摘The feasibility of emploving non-ionic surfactant （Triton X-100） as an alternative and effective solventfor the microwave-assisted extraction of glycyrrhizic acid （GA） and liquiritin （LQ） from licorice root was studied.The optimal extraction parameters based on the microwave-assisted micellar extraction technique were determined.Under the optimal conditions, i.e. 5% （by volume） Triton X-100, microwave-assisted extraction for 3--5min at 373K, the percentage extraction of active ingredients reached the highest value. The preconcentration tactor for GA and L＇Q （about 13.5） and the extraction efficiency for these two ingredients approached 100% showed the coupling of microwave-assisted extraction and cloud-point extraction could be employed as a new and. effective techniquefor the rapid extraction and preconcentration of pharrnacologically active ingredients from medicinal plants SUCh aslicorice root without disturbing chromatographic analysis.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean government(MSIT)(NRF-2021R1A2C1095669 and NRF-2021R1F1A104936)。
文摘The construction of a homojunction is an effective approach for addressing issues such as slow charge separation and charge-transfer kinetics in photoanodes.In the present work,we designed a gradient Si-and Ti-doped Fe_(2)O_(3) homojunction photoanode to improve the photoelectrochemical(PEC)performance of a Ti-doped Fe_(2)O_(3) photoanode.Ti-FeOOH nanocorals were synthesized using a hydrothermal process,and Si-FeOOH was grown on Ti-FeOOH nanocorals using a rapid and facile microwaveassisted(MW)technique.By varying the MW irradiation time,the thickness of the Si/Ti:Fe_(2)O_(3) photoanode was adjusted and an optimized 3-Si/Ti:Fe_(2)O_(3) photoelectrode was achieved with a significantly enhanced photocurrent density(1.37 mA cm^(-2) at 1.23 V vs.RHE)and a cathodic shift of the onset potential(150 mV)compared with that of bare Ti-Fe_(2)O_(3).This enhanced PEC performance can be ascribed to homojunction formation and Si gradient doping.The Si dopant increased the donor concentration and the formation of a homojunction improved the intrinsic built-in electric field,thereby promoting charge separation and charge transfer.Furthermore,the as-formed homojunction passivated the surfacetrapping states,consequently improving the charge transfer efficiency(60%at 1.23 VRHE)at the photoanode/electrolyte interface.These findings could pave the way for the microwave-assisted fabrication of diverse efficient homojunction photoanodes for PEC water splitting applications.
