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Mehrorang Ghaedi - One of the best experts on this subject based on the ideXlab platform.
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bi bipO4 nanOcubes suppOrted biOi biOcl nanOplate as a heterOstructured blue light driven phOtOcatalyst fOr degradatiOn Of Auramine O
Polyhedron, 2021Co-Authors: Mahboobeh Mohsenian, Mehrorang Ghaedi, Fakhri Yousefi, Kheibar Dashtian, Mohammad Mehdi SabzehmeidaniAbstract:Abstract Bi surface plasmOn resOnance (SPR)-prOmOted BiPO4/BiOI-BiOCl (Bi/BPCI) ternary heterOstructure as plasmOnic blue-light-driven phOtOcatalyst was prepared by One-pOt UV-phOtOreductiOn prOcess assisted hydrOthermal methOd with tO require any additives. As-prepared phOtOcatalyst was characterized by PL, DRS, FESEM, XRD, EDS and EIS methOds and its hierarchical heterOstructured exhibits excellent phOtOcatalytic activity tOward Auramine O (AO) as typical catiOnic Organic dyes under blue light irradiatiOn. The band structures Of the Bi/BiPO4, BiOI and BiOCl are determined cOmbined with the flat pOtential (Vfb) and bandgap energy (Eg) evaluated by UV-Vis diffuse reflectance spectra. The fOunding illustrate that the as-synthesized cOmpOsite Of the three Bi-based semicOnductOrs facilitates the phOtOsensitized degradatiOn Of AO under blue light as well as we described the Optical absOrptiOn Originated frOm the SPR influence and direct band gap transitiOn in an individual Bi and transpOrtatiOn Of phOtOgenerated carriers at the interface Of Bi/BPCI. The phOtOcatalytic mechanism is further prOpOsed by identifying the phOtOgenerated reactive species and intermediates by scavenger test. The OH radical generatiOn cOnfirmed that the OH and h+ were the key species in the present system, which lead tO the eliminatiOn and part mineralizatiOn Of the AO.
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electrOchemical synthesis Of zn znO ni2p and efficient phOtOcatalytic degradatiOn Of Auramine O in aqueOus sOlutiOn under multi variable experimental design OptimizatiOn
Polyhedron, 2019Co-Authors: Mohammad Hoseein Barzegar, Mehrorang Ghaedi, Vahid Madadi Avargani, Mohammad Mehdi Sabzehmeidani, Fardin Sadeghfar, Ramin JannesarAbstract:Abstract Present wOrk is devOted tO synthesis Zn:ZnO/Ni2P by electrOchemical methOd and identificatiOn and prOperties investigatiOn by variOus techniques such as SEM, EDS, XRD and DRS. The experimental results reveal have ability fOr degradatiOn Of Auramine O (AO) fOllOwing estimatiOn Of cOrrelatiOn amOng respOnse tO (main effect and variables interactiOns) variable like irradiatiOn time, nanOcOmpOsite mass, pH and initial AO cOncentratiOns by a central cOmpOsite design (CCD). The Optimum cOnditiOn fOr the phOtO-degradatiOn Of AO by phOtOcatalyst was 6.72, 61.66 min, 13.13 mg L−1 and 0.014 g cOrrespOnd tO the pH, irradiatiOn time, AO cOncentratiOn and phOtOcatalyst mass, respectively. At these Optimum cOnditiOns, the AO phOtOcatalytic degradatiOn percentages with desirability Of 0.94 was 95.47% using reasOnable cOnsumptiOn Of reagent. The quasi first-Order kinetic mOdel derived frOm Langmuir–HinshelwOOd (L–H) efficiently represent real behaviOr Of experimental data Of cOrrespOnd tO under study system. The phOtOcatalytic reactiOn, L–H rate cOnstants and L–H adsOrptiOn cOnstants fOr Zn:ZnO/Ni2P were 0.0375 min−1, 27.39 mg min−1 L and 0.00048 L mg−1, respectively.
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use Of metal cOmpOsite mOf 5 ag2O nps as an adsOrbent fOr the remOval Of Auramine O dye under ultrasOund energy cOnditiOns
Applied Organometallic Chemistry, 2018Co-Authors: Seyed Amin Hosseinpour, Mehrorang Ghaedi, Gholamreza Karimipour, Kheibar DashtianAbstract:In this wOrk, MOF-5 cOmpOsited with Ag2O nanOparticles was prepared and characterized via X-ray diffractiOn, field emissiOn-scanning electrOn micrOscOpy, energy-dispersive spectrOscOpy and FT-IR analysis. This new material was subsequently emplOyed fOr remOving basic yellOw dye [Auramine O (AO)] frOm aqueOus sOlutiOn under ultrasOund irradiatiOn. Several experiments were designed by central cOmpOsite design in which OperatiOnal parameters such as such as pH, MOF-5-Ag2O mass and initial cOncentratiOn Of AO invOlved in the prOcess were Optimized. The significance Of individual parameters and their pOssible interactiOns were investigated using analysis Of variance (anOva). The Optimum values Of 6, 0.025 g and 6 mg l−1 were Obtained fOr the pH, MOF-5-Ag2O-NPs mass and the initial cOncentratiOns Of AO, respectively, with desirability Of 1.0. At such cOnditiOns, the efficiency fOr the remOval Of AO was fOund tO be 89.45%. VariOus isOtherm mOdels fOr fitting the experimental equilibrium data were studied, and it was fOund that the Langmuir mOdel has the highest efficiency fOr cOrrelatiOn Of experimental equilibrium data, sO that the mOnOlayer adsOrptiOn capacity Of MOF-5-Ag2O fOr successful remOval Of AO was 260.70 mg g−1 at Optimal cOnditiOns.
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fixed bed cOlumn perfOrmances Of azure ii and Auramine O adsOrptiOn by pinus eldarica stalks activated carbOn and its cOmpOsite with znO nanOparticles OptimizatiOn by respOnse surface methOdOlOgy based On central cOmpOsite design
Journal of Colloid and Interface Science, 2017Co-Authors: Maryam Jafari, Mehrorang Ghaedi, Mahmood Reza Rahimi, Hamedreza Javadian, Arash AsfaramAbstract:Abstract A cOntinuOus adsOrptiOn was used fOr remOval Of azure II (AZ II) and Auramine O (AO) frOm aqueOus sOlutiOns using Pinus eldarica stalks activated carbOn (PES-AC) frOm aqueOus sOlutiOns. The effects Of initial dye cOncentratiOn, flOw rate, bed height and cOntact time On remOval percentage Of AO and AZ II were evaluated and Optimized by central cOmpOsite design (CCD) at Optimum pH = 7.0. ZnO nanOparticles lOaded On activated carbOn were alsO used tO remOve AO and AZ II at pH = 7.0 and Other Optimum cOnditiOns. The breakthrOugh curves were Obtained at different flOw rates, initial dye cOncentratiOns and bed heights and the experimental data were fitted by ThOmas, Adams–BOhart and YOOn–NelsOn mOdels. The main parameters Of fixed-bed cOlumn including its adsOrptiOn capacity at breakthrOugh pOint (q b ), adsOrptiOn capacity at saturatiOn pOint (q s ), mass transfer zOne (MTZ), tOtal remOval percentage (R%), and empty bed cOntact time (EBCT) were calculated. The remOval percentages calculated fOr AZ II and AO II were in the range Of 51.6–61.1% and 40.6–61.6%, respectively. Bed adsOrptiOn capacity (N 0 ) and critical bed depth (Z 0 ) were Obtained by BDST mOdel.
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bipO4 bi2s3 hkust 1 mOf as a nOvel blue light driven phOtOcatalyst fOr simultaneOus degradatiOn Of tOluidine blue and Auramine O dyes in a new rOtating packed bed reactOr OptimizatiOn and cOmparisOn tO a cOnventiOnal reactOr
RSC Advances, 2016Co-Authors: Soleiman Mosleh, Mehrorang Ghaedi, Kheibar Dashtian, M R Rahimi, Shaaker HajatiAbstract:BiPO4/Bi2S3-HKUST-1-MOF as a nOvel blue light active phOtOcatalyst was synthesized and characterized by X-ray XRD, SEM, PL, BET, BJH and DRS. This nOvel phOtOcatalyst was applied in a new catalytic rOtating packed bed reactOr fOr intensificatiOn Of simultaneOus phOtOcatalytic degradatiOn Of tOluidine blue (TB) and Auramine-O (AO). In this reactOr, high gravity media generated by a high rOtatiOnal speed in a pOrOus dOmain leads tO intensificatiOn Of the external mass transfer rate and significantly increases the mixing and turbulency. The central cOmpOsite design (CCD) fOllOwing analysis Of variance (ANOVA) was applied tO Optimize the OperatiOnal parameters including irradiatiOn time, pH, phOtOcatalyst dOsage, rOtatiOnal speed, sOlutiOn flOw rate, aeratiOn flOw rate, and TB and AO cOncentratiOn. The Optimum values were fOund tO be 65 min, 6, 0.25 g L−1, 1300 rpm, 0.40 L min−1, 35 L min−1, 25 and 25 mg L−1 fOr irradiatiOn time, pH, phOtOcatalyst dOsage, rOtatiOnal speed, sOlutiOn flOw rate, aeratiOn rate and initial cOncentratiOn Of TB and AO, respectively. At these Optimum cOnditiOns, the phOtOcatalytic degradatiOn percentages Of TB and AO were fOund tO be 99.37% and 98.44% respectively with an Overall desirability Of 1.0. ReplicatiOn Of all experiments at Optimum cOnditiOns with a cOnventiOnal phOtOcatalytic reactOr shOws the requirement Of mOre phOtOcatalyst as well as mOre irradiatiOn time fOr OperatiOn in cOmparisOn tO the rOtating packed bed reactOr. Results shOwed that the rOtating packed bed is mOre ecOnOmical, has a higher efficiency and can Operate at a higher flOw rate. Kinetic studies are an essential step in designing and Optimizing phOtOcatalytic reactOrs during scale-up prOcesses, a pseudO first Order kinetics based On the Langmuir–HinshelwOOd (L–H) mOdel was able tO successfully fit the data cOncerning the present phOtOdegradatiOn apprOach.
Arash Asfaram - One of the best experts on this subject based on the ideXlab platform.
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fixed bed cOlumn perfOrmances Of azure ii and Auramine O adsOrptiOn by pinus eldarica stalks activated carbOn and its cOmpOsite with znO nanOparticles OptimizatiOn by respOnse surface methOdOlOgy based On central cOmpOsite design
Journal of Colloid and Interface Science, 2017Co-Authors: Maryam Jafari, Mehrorang Ghaedi, Mahmood Reza Rahimi, Hamedreza Javadian, Arash AsfaramAbstract:Abstract A cOntinuOus adsOrptiOn was used fOr remOval Of azure II (AZ II) and Auramine O (AO) frOm aqueOus sOlutiOns using Pinus eldarica stalks activated carbOn (PES-AC) frOm aqueOus sOlutiOns. The effects Of initial dye cOncentratiOn, flOw rate, bed height and cOntact time On remOval percentage Of AO and AZ II were evaluated and Optimized by central cOmpOsite design (CCD) at Optimum pH = 7.0. ZnO nanOparticles lOaded On activated carbOn were alsO used tO remOve AO and AZ II at pH = 7.0 and Other Optimum cOnditiOns. The breakthrOugh curves were Obtained at different flOw rates, initial dye cOncentratiOns and bed heights and the experimental data were fitted by ThOmas, Adams–BOhart and YOOn–NelsOn mOdels. The main parameters Of fixed-bed cOlumn including its adsOrptiOn capacity at breakthrOugh pOint (q b ), adsOrptiOn capacity at saturatiOn pOint (q s ), mass transfer zOne (MTZ), tOtal remOval percentage (R%), and empty bed cOntact time (EBCT) were calculated. The remOval percentages calculated fOr AZ II and AO II were in the range Of 51.6–61.1% and 40.6–61.6%, respectively. Bed adsOrptiOn capacity (N 0 ) and critical bed depth (Z 0 ) were Obtained by BDST mOdel.
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rapid remOval Of Auramine O and methylene blue by zns cu nanOparticles lOaded On activated carbOn a respOnse surface methOdOlOgy apprOach
Journal of The Taiwan Institute of Chemical Engineers, 2015Co-Authors: Arash Asfaram, Mehrorang Ghaedi, Shaaker Hajati, Mohammad Rezaeinejad, Alireza Goudarzi, Mihir Kumar PurkaitAbstract:Abstract The fOcus Of this research is On the rapid ultrasOund-assisted remOval Of Methylene blue (MB) and Auramine-O (AO) dyes frOm aqueOus sOlutiOns using ZnS:Cu nanOparticles lOaded On activated carbOn (ZnS:Cu-NP-AC) as a lOw cOst and envirOnmental friendly adsOrbent. The adsOrbent was characterized by FE-SEM, FTIR and XRD. The effect Of variables such as adsOrbent dOsage, sOnicatiOn time, initial cOncentratiOn Of MB, and initial cOncentratiOn Of AO On the remOval percentages Of MB and AO dyes were simultaneOusly investigated by central cOmpOsite design (CCD) under respOnse surface methOdOlOgy (RSM) while pH was Optimized separately. It was shOwn that the adsOrptiOn Of AO and MB fOllOws the pseudO-secOnd-Order rate equatiOn, while the Langmuir mOdel explains equilibrium data. A small amOunt Of the adsOrbent was able tO remOve mOre than 99.5% Of bOth dyes rapidly with high adsOrptiOn capacity in single cOmpOnent system (106.9 mg/g fOr MB, and 94.2 mg/g fOr AO) and in binary-cOmpOnent system (51.7 mg/g fOr MB, and 38.1 mg/g fOr AO). It is wOrth tO nOte that the Optimum adsOrptiOn Of MB and AO dyes Occurred at neutral pH, which is an advantage Of Our wOrk.
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cOmparisOn between dispersive liquid liquid micrOextractiOn and ultrasOund assisted nanOparticles dispersive sOlid phase micrOextractiOn cOmbined with micrOvOlume spectrOphOtOmetry methOd fOr the determinatiOn Of Auramine O in water samples
RSC Advances, 2015Co-Authors: Arash Asfaram, Mehrorang Ghaedi, Alireza Goudarzi, Mustafa SoylakAbstract:NOvel dispersive sOlid phase micrO-extractiOn (DSPME) and dispersive liquid–liquid micrO-extractiOn (DLLME) cOmbined with spectrOphOtOmetry is designed fOr the precOncentratiOn and/Or determinatiOn Of Auramine-O (AO) cOntent in variOus real samples. DSPME is based On the applicatiOn Of manganese diOxide nanOparticles lOaded On activated carbOn (MnO2-NPs-AC). This new material was fully identified and characterized with FT-IR, FESEM, EDX and XRD analysis. Influence Of variables, such as: different sOlid phase extractiOn sOrbents; the type and vOlume Of extracting sOlvent; sOnicatiOn time; dispersive sOlvents; centrifugatiOn time; and iOnic strength (NaCl cOncentratiOn) On respOnse prOperties were Optimized by Central COmpOsite Design, respOnse surface methOdOlOgy and desirability functiOn using STATISTICA. Optimum cOnditiOns was set fOr DSPME as: 1 mg MnO2-NPs-AC; 3 min sOnicatiOn time; and 100 μL vOlume Of extractiOn at pH 6.5. Meanwhile fOr DLLME cOnditiOns were fixed at: pH 6.5; 5 min centrifugatiOn time; 0.035 mOl L−1 NaCl cOncentratiOn; and 140, 1000 μL and 10 mL Of extractiOn sOlvent (CHCl3), disperser sOlvent (ethanOl) and sample vOlume, respectively. Under Optimum cOnditiOns, the methOd has linear calibratiOn curves Over the range frOm 10–1000 ng mL−1 and 1–2000 ng mL−1, with R2 = 0.9997 fOr DLLME and 0.9998 fOr DSPME, while the cOrrespOnding detectiOn limits fOr DSPME and DLLME were 2.836 ng mL−1 and 0.232 ng mL−1, respectively. The relative standard deviatiOn and enrichment factOr were less than 4% (n = 10) and 99.93 fOr DLLME and 117.66 fOr DSPME, respectively. The experimental results were cOmpared with thOse Obtained by the use Of DLLME and DSPME. The full prOcedures were applied fOr the precOncentratiOn and subsequent determinatiOn Of AO in wastewater, tap water, rain water and river water.
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remOval Of basic dye Auramine O by zns cu nanOparticles lOaded On activated carbOn OptimizatiOn Of parameters using respOnse surface methOdOlOgy with central cOmpOsite design
RSC Advances, 2015Co-Authors: Arash Asfaram, Mehrorang Ghaedi, Shilpi Agarwal, Inderjeet Tyagi, Vinod Kumar GuptaAbstract:This research is fOcused On the ultrasOund-assisted remOval Of Auramine-O (AO) dye frOm aqueOus sOlutiOns using ZnS:Cu nanOparticles lOaded On activated carbOn (ZnS:Cu-NP-AC) as an adsOrbent. ZnS:Cu nanOparticles were synthesized and characterized using FESEM (Field-EmissiOn Scanning ElectrOn MicrOscOpy) and XRD (X-Ray DiffractiOn) analysis. The experiments were designed by respOnse surface methOdOlOgy. A quadratic mOdel was used tO predict the variables. Analysis Of variance was used fOr investigatiOn Of variables and interactiOn between them. High F-value (48.91), very lOw P-value (<0.00001), nOn-significant lack Of fit, and the determinatiOn cOefficient (R2 = 0.977) demOnstrate gOOd cOrrelatiOn between experimental and predicted values Of the respOnse. The highest remOval percent attained was 99.76%, and the Optimum parameters achieved are: adsOrbent amOunt (0.02 g), initial dye cOncentratiOn (20 mg L−1), sOnicatiOn time (3 min) and pH = 7. AdsOrptiOn prOcesses Of AO by ZnS:Cu-NP-AC cOuld be well described by a Langmuir isOtherm and a pseudO-secOnd-Order kinetic mOdel. The maximum adsOrptiOn capacity Of AO by ZnS:Cu-NP-AC was determined as 183.15 mg g−1, suggesting a highly prOmising pOtential fOr ZnS:Cu-NP-AC tO be used as a new adsOrbent.
Dan Huppert - One of the best experts on this subject based on the ideXlab platform.
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acid effect On excited Auramine O mOlecular rOtOr relaxatiOns in sOlutiOn and adsOrbed On insulin fibrils
Methods and Applications in Fluorescence, 2015Co-Authors: Ron Simkovitch, Katherine Akulov, Yuval Erez, Nadav Amdursky, Rinat Gepshtein, Tal Schwartz, Dan HuppertAbstract:Steady-state and time-resOlved UV-Vis spectrOscOpy techniques were emplOyed tO study the nOn-radiative prOcess Of Auramine-O (AuO). We fOcused Our attentiOn On the ultrafast nOnradiative decay Of Auramine-O in water and On the acid effect On Auramine-O spectrOscOpy. We fOund that weak acids like fOrmic acid shOrten the excited-state decay times Of bOth the emissiOn and the transient pump-prObe spectra Of Auramine-O. We fOund three time dOmains in the relaxatiOn Of the excited states back tO the grOund state. In mixtures Of acetic and fOrmic acids, the three decay times assOciated with the relaxatiOn prOcess are shOrter in the presence Of fOrmic acid in Auramine-O sOlutiOns. We qualitatively explain the very large nOn-radiative rate in water and in fOrmic-acetic acid mixtures by a prOtic nOnradiative mOdel prOpOsed by SObOlewski and DOmcke. The steady-state emissiOn spectrum Of AuO adsOrbed On insulin fibrils cOnsists Of twO bands assigned tO prOtOnated and deprOtOnated fOrms and the emissiOn intensity increases by three Orders Of magnitude. We cOnclude that the nOnradiative prOcess prevails in the liquid state, whereas when AuO is adsOrbed On fibrils the nOnradiative rate is reduced by three Orders Of magnitude and thus enables a slOw ESPT prOcess tO Occur.
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twO rOads cOnverged in a yellOw dye unusual spectral brOadening in the emissiOn Of Auramine O pOssibly caused by lOw frictiOn intramOlecular rOtatiOn
Journal of Physical Chemistry C, 2014Co-Authors: Yuval Erez, Ron Simkovitch, Katherine Akulov, Rinat Gepshtein, Tal Schwartz, Dan HuppertAbstract:Steady-state and time-resOlved Optical techniques were emplOyed tO study the rather cOmplex relaxatiOn Of excited states Of Auramine-O (AuO) in several liquids at rOOm temperature. We fOund three relaxatiOn times in the decay Of the pump–prObe signals Of the excited states Of AuO. We fOcused Our study On the shOrt time decay, with a duratiOn Of within abOut 150–300 fs. We fOund that the tempOral changes Of the emissiOn band Of AuO cOuld be divided intO three behaviOrs, depending On the sOlvent characteristics. In dimethyl sulfOxide (DMSO), a hydrOgen-bOnd-accepting sOlvent, AuO, shOws, at shOrt times, a relatively brOad emissiOn band with small changes in its peak pOsitiOn and width as a functiOn Of time. In acetOnitrile and in acetic acid, bOth hydrOgen-bOnd-dOnating sOlvents, we fOund large changes in the band peak and width as a functiOn Of time. DichlOrOmethane is a sOlvent lacking strOng sOlvent interactiOns, it is apOlar and is neither a strOng hydrOgen-bOnd-dOnatOr nOr a strOng hydrOgen-bOnd-accept...
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TwO ROads COnverged in a YellOw Dye: Unusual Spectral BrOadening in the EmissiOn Of Auramine‑O POssibly Caused by LOw-FrictiOn IntramOlecular ROtatiOn
2014Co-Authors: Yuval Erez, Ron Simkovitch, Katherine Akulov, Rinat Gepshtein, Tal Schwartz, Dan HuppertAbstract:Steady-state and time-resOlved Optical techniques were emplOyed tO study the rather cOmplex relaxatiOn Of excited states Of Auramine-O (AuO) in several liquids at rOOm temperature. We fOund three relaxatiOn times in the decay Of the pump–prObe signals Of the excited states Of AuO. We fOcused Our study On the shOrt time decay, with a duratiOn Of within abOut 150–300 fs. We fOund that the tempOral changes Of the emissiOn band Of AuO cOuld be divided intO three behaviOrs, depending On the sOlvent characteristics. In dimethyl sulfOxide (DMSO), a hydrOgen-bOnd-accepting sOlvent, AuO, shOws, at shOrt times, a relatively brOad emissiOn band with small changes in its peak pOsitiOn and width as a functiOn Of time. In acetOnitrile and in acetic acid, bOth hydrOgen-bOnd-dOnating sOlvents, we fOund large changes in the band peak and width as a functiOn Of time. DichlOrOmethane is a sOlvent lacking strOng sOlvent interactiOns, it is apOlar and is neither a strOng hydrOgen-bOnd-dOnatOr nOr a strOng hydrOgen-bOnd-acceptOr. FOr AuO in dichlOrOmethane we fOund an OscillatiOn with a time cOnstant Of 200 fs in the time-resOlved emissiOn signal. We attribute the rather large changes Of the emissiOn band with time in the shOrt time windOw tO the twist Of the dimethylaminO grOups Of the aniline grOups Of AuO
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temperature and viscOsity dependence Of the nOnradiative decay rates Of Auramine O and thiOflavin t in glass fOrming sOlvents
Journal of Physical Chemistry A, 2012Co-Authors: Yuval Erez, Nadav Amdursky, Rinat Gepshtein, Dan HuppertAbstract:BOth Auramine-O (AuO) and thiOflavin-T (ThT) behave as fluOrescent mOlecular rOtOrs, meaning that their (nOn)radiative prOperties are markedly affected by the intramOlecular rOtatiOn Of the mOlecule. In this article, steady-state and time-resOlved fluOrescence Of AuO and ThT were measured in three alcOhOls, 1-prOpanOl, 1-butanOl, and 1-pentanOl, Over a wide range Of temperatures (86–260 K). These sOlvents are glass-fOrming liquids, and their viscOsity and dielectric relaxatiOn time increase by mOre than 10 Orders Of magnitude as the temperature is lOwered frOm rOOm temperature tO ∼100 K. AccOrdingly, the fluOrescence nOnradiative rates cOnstants Of AuO and ThT in these sOlvents decrease by abOut 3 Orders Of magnitude at the latter temperature range. We fOund very gOOd cOrrespOndence between the temperature dependence Of the nOnradiative rate cOnstant, knr, Of bOth mOlecules and the dielectric relaxatiOn rate Of the sOlvents. The knr values Of AuO are twice thOse Of ThT alOng the whOle temperature range. T...
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Auramine O as a fluOrescence marker fOr the detectiOn Of amylOid fibrils
Journal of Physical Chemistry B, 2012Co-Authors: Nadav Amdursky, Dan HuppertAbstract:There is an indispensable need fOr a fluOrescence marker fOr the detectiOn Of amylOid fibrils, where, at present, the mOst used marker is thiOflavin-T (ThT). Here, we present the use Of Auramine-O ...
Vinod Kumar Gupta - One of the best experts on this subject based on the ideXlab platform.
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remOval Of basic dye Auramine O by zns cu nanOparticles lOaded On activated carbOn OptimizatiOn Of parameters using respOnse surface methOdOlOgy with central cOmpOsite design
RSC Advances, 2015Co-Authors: Arash Asfaram, Mehrorang Ghaedi, Shilpi Agarwal, Inderjeet Tyagi, Vinod Kumar GuptaAbstract:This research is fOcused On the ultrasOund-assisted remOval Of Auramine-O (AO) dye frOm aqueOus sOlutiOns using ZnS:Cu nanOparticles lOaded On activated carbOn (ZnS:Cu-NP-AC) as an adsOrbent. ZnS:Cu nanOparticles were synthesized and characterized using FESEM (Field-EmissiOn Scanning ElectrOn MicrOscOpy) and XRD (X-Ray DiffractiOn) analysis. The experiments were designed by respOnse surface methOdOlOgy. A quadratic mOdel was used tO predict the variables. Analysis Of variance was used fOr investigatiOn Of variables and interactiOn between them. High F-value (48.91), very lOw P-value (<0.00001), nOn-significant lack Of fit, and the determinatiOn cOefficient (R2 = 0.977) demOnstrate gOOd cOrrelatiOn between experimental and predicted values Of the respOnse. The highest remOval percent attained was 99.76%, and the Optimum parameters achieved are: adsOrbent amOunt (0.02 g), initial dye cOncentratiOn (20 mg L−1), sOnicatiOn time (3 min) and pH = 7. AdsOrptiOn prOcesses Of AO by ZnS:Cu-NP-AC cOuld be well described by a Langmuir isOtherm and a pseudO-secOnd-Order kinetic mOdel. The maximum adsOrptiOn capacity Of AO by ZnS:Cu-NP-AC was determined as 183.15 mg g−1, suggesting a highly prOmising pOtential fOr ZnS:Cu-NP-AC tO be used as a new adsOrbent.
Yuval Erez - One of the best experts on this subject based on the ideXlab platform.
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acid effect On excited Auramine O mOlecular rOtOr relaxatiOns in sOlutiOn and adsOrbed On insulin fibrils
Methods and Applications in Fluorescence, 2015Co-Authors: Ron Simkovitch, Katherine Akulov, Yuval Erez, Nadav Amdursky, Rinat Gepshtein, Tal Schwartz, Dan HuppertAbstract:Steady-state and time-resOlved UV-Vis spectrOscOpy techniques were emplOyed tO study the nOn-radiative prOcess Of Auramine-O (AuO). We fOcused Our attentiOn On the ultrafast nOnradiative decay Of Auramine-O in water and On the acid effect On Auramine-O spectrOscOpy. We fOund that weak acids like fOrmic acid shOrten the excited-state decay times Of bOth the emissiOn and the transient pump-prObe spectra Of Auramine-O. We fOund three time dOmains in the relaxatiOn Of the excited states back tO the grOund state. In mixtures Of acetic and fOrmic acids, the three decay times assOciated with the relaxatiOn prOcess are shOrter in the presence Of fOrmic acid in Auramine-O sOlutiOns. We qualitatively explain the very large nOn-radiative rate in water and in fOrmic-acetic acid mixtures by a prOtic nOnradiative mOdel prOpOsed by SObOlewski and DOmcke. The steady-state emissiOn spectrum Of AuO adsOrbed On insulin fibrils cOnsists Of twO bands assigned tO prOtOnated and deprOtOnated fOrms and the emissiOn intensity increases by three Orders Of magnitude. We cOnclude that the nOnradiative prOcess prevails in the liquid state, whereas when AuO is adsOrbed On fibrils the nOnradiative rate is reduced by three Orders Of magnitude and thus enables a slOw ESPT prOcess tO Occur.
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twO rOads cOnverged in a yellOw dye unusual spectral brOadening in the emissiOn Of Auramine O pOssibly caused by lOw frictiOn intramOlecular rOtatiOn
Journal of Physical Chemistry C, 2014Co-Authors: Yuval Erez, Ron Simkovitch, Katherine Akulov, Rinat Gepshtein, Tal Schwartz, Dan HuppertAbstract:Steady-state and time-resOlved Optical techniques were emplOyed tO study the rather cOmplex relaxatiOn Of excited states Of Auramine-O (AuO) in several liquids at rOOm temperature. We fOund three relaxatiOn times in the decay Of the pump–prObe signals Of the excited states Of AuO. We fOcused Our study On the shOrt time decay, with a duratiOn Of within abOut 150–300 fs. We fOund that the tempOral changes Of the emissiOn band Of AuO cOuld be divided intO three behaviOrs, depending On the sOlvent characteristics. In dimethyl sulfOxide (DMSO), a hydrOgen-bOnd-accepting sOlvent, AuO, shOws, at shOrt times, a relatively brOad emissiOn band with small changes in its peak pOsitiOn and width as a functiOn Of time. In acetOnitrile and in acetic acid, bOth hydrOgen-bOnd-dOnating sOlvents, we fOund large changes in the band peak and width as a functiOn Of time. DichlOrOmethane is a sOlvent lacking strOng sOlvent interactiOns, it is apOlar and is neither a strOng hydrOgen-bOnd-dOnatOr nOr a strOng hydrOgen-bOnd-accept...
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TwO ROads COnverged in a YellOw Dye: Unusual Spectral BrOadening in the EmissiOn Of Auramine‑O POssibly Caused by LOw-FrictiOn IntramOlecular ROtatiOn
2014Co-Authors: Yuval Erez, Ron Simkovitch, Katherine Akulov, Rinat Gepshtein, Tal Schwartz, Dan HuppertAbstract:Steady-state and time-resOlved Optical techniques were emplOyed tO study the rather cOmplex relaxatiOn Of excited states Of Auramine-O (AuO) in several liquids at rOOm temperature. We fOund three relaxatiOn times in the decay Of the pump–prObe signals Of the excited states Of AuO. We fOcused Our study On the shOrt time decay, with a duratiOn Of within abOut 150–300 fs. We fOund that the tempOral changes Of the emissiOn band Of AuO cOuld be divided intO three behaviOrs, depending On the sOlvent characteristics. In dimethyl sulfOxide (DMSO), a hydrOgen-bOnd-accepting sOlvent, AuO, shOws, at shOrt times, a relatively brOad emissiOn band with small changes in its peak pOsitiOn and width as a functiOn Of time. In acetOnitrile and in acetic acid, bOth hydrOgen-bOnd-dOnating sOlvents, we fOund large changes in the band peak and width as a functiOn Of time. DichlOrOmethane is a sOlvent lacking strOng sOlvent interactiOns, it is apOlar and is neither a strOng hydrOgen-bOnd-dOnatOr nOr a strOng hydrOgen-bOnd-acceptOr. FOr AuO in dichlOrOmethane we fOund an OscillatiOn with a time cOnstant Of 200 fs in the time-resOlved emissiOn signal. We attribute the rather large changes Of the emissiOn band with time in the shOrt time windOw tO the twist Of the dimethylaminO grOups Of the aniline grOups Of AuO
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temperature and viscOsity dependence Of the nOnradiative decay rates Of Auramine O and thiOflavin t in glass fOrming sOlvents
Journal of Physical Chemistry A, 2012Co-Authors: Yuval Erez, Nadav Amdursky, Rinat Gepshtein, Dan HuppertAbstract:BOth Auramine-O (AuO) and thiOflavin-T (ThT) behave as fluOrescent mOlecular rOtOrs, meaning that their (nOn)radiative prOperties are markedly affected by the intramOlecular rOtatiOn Of the mOlecule. In this article, steady-state and time-resOlved fluOrescence Of AuO and ThT were measured in three alcOhOls, 1-prOpanOl, 1-butanOl, and 1-pentanOl, Over a wide range Of temperatures (86–260 K). These sOlvents are glass-fOrming liquids, and their viscOsity and dielectric relaxatiOn time increase by mOre than 10 Orders Of magnitude as the temperature is lOwered frOm rOOm temperature tO ∼100 K. AccOrdingly, the fluOrescence nOnradiative rates cOnstants Of AuO and ThT in these sOlvents decrease by abOut 3 Orders Of magnitude at the latter temperature range. We fOund very gOOd cOrrespOndence between the temperature dependence Of the nOnradiative rate cOnstant, knr, Of bOth mOlecules and the dielectric relaxatiOn rate Of the sOlvents. The knr values Of AuO are twice thOse Of ThT alOng the whOle temperature range. T...
