جستجوی مقالات مرتبط با کلیدواژه « Raman Spectroscopy » در نشریات گروه « شیمی »
تکرار جستجوی کلیدواژه « Raman Spectroscopy » در نشریات گروه « علوم پایه »-
In this research study, Raman spectroscopy was utilized as a principal tool to assess the vibrational dynamics of carbon nanostructures (carbon allotropes) and develop a structural description. This work was concerned with carbon allotropes due to their various applications in many fields. Raman spectroscopy as a practical characterization technique of carbon allotropes was investigated. Also, the spectral analysis of FT-IR was presented too. Raman spectral analysis demonstrated the basic bands, including Radial breathing mode (RBM), G, D, and 2D-bands, which are affected due to structural differences of the carbon allotropes. This yields information about the crystal structure and its interesting physical properties.
Keywords: Raman spectroscopy, FTIR, RBM, Nanostructures} -
کانسار مسجدداغی در زون ماگمایی- فلززایی ارسباران و در تقسیم بندی زون های ساختاری ایران در زون البرز- آذربایجان واقع شده. وسیع ترین واحد سنگی منطقه آندزیت تا تراکی آندزیت بوده و آگلومرای آندزیتی، توف سنگی لاتیتی و هورنبلند بازالت پورفیری در ارتفاعات شرقی و فلیش های ایوسن در جنوب منطقه گسترش دارند. توده میزبان کانه زایی دیوریت پورفیری و دگرسانی ها شامل پتاسیک، فیلیک، آرژیلیک و سیلیسی شدن می باشد. بیشترین بافت کانه زایی بافت پراکنده بوده بافت های پرکننده فضای خالی، رگه و رگچه نیز شایع می باشد. علاوه بر زونهای استوک ورک و رگه های ضخیم سیلیسی، وجود دایک های دیوریتی و مافیکی، رگه های سیلیسی خاکستری مینرالیزه، سیلیسی سفید، سیلیسی- باریتی، سولفیدی، ژیپسی و کلسیتی از پدیده های مهم کانسار مسجدداغی می باشد. مطالعات پتروگرافی 26 مقطع دوبر صیقل و سنجش پارامترهای ژیوترمومتری 105میانبار سیال اولیه در چهار گروه رگه سیلیسی خاکستری، سیلیسی سفید، سیلیسی خاکستری- سفید و سیلیسی- باریتی 6 گمانه حفاری صورت گرفت. وجود فازهای جامد ناشناخته، فازهای جامد اپک همراه فازهای نمک و دمای ایوتکتیک (میانگینC86/40-) میانبارهای سیال مسجدداغی، ضرورت شناسایی همه فازهای داخل میانبارهای سیال را تقویت نمود. تعداد10 میانبار سیال براساس مطالعات پتروگرافی انتخاب و با روش طیف سنجی لیزر رامان آنالیز گردید. در طیف سنجی لیزر رامان بر اساس پیک های اصلی شدت رامان کانی هایی با ترکیب شیمیایی مگنتیت، انگلزیت، مالاکیت، سروزیت، کروندوم، اورتوکلاز، انیدریت، فورستریت، رتیل، هماتیت، آمبلی گونیت، اپسومیت، کوارتز، باریت، بلند، آرتینیت، کریزوتیل، سانیدین، پاراگاسیت و سولفور و دی اکسیدکربن در داخل میانبارهای سیال کانسار مسجدداغی شناسایی گردید.کلید واژگان: طیف سنجی رامان, میانبار سیال, دگرسانی, فازهای شیمیایی, مسجدداغی}A Quarterly Publication The Application of Chemistry in Environment, Volume:12 Issue: 46, 2021, PP 39 -53Masjed daghi ore is located within the magmatic-metallogenic zone of Arasbaran and within the division of structural zones in Iran in Alborz-Azerbaijan zone.The vastest rocks in mineralization area are andesite to trachyandesite. There are latite tuff, agglomerate andesite, and hornblende porphyry basalt in eastern hills and Eocene flysch in south of the regionThe host intrusive rocks of the mineralization are diorite porphyry are diorite porphyry and alterations include potassic, phyllic, argillic and silicification.The most prevalent mineralization texture is the dispersive texture and other open-space-filling texture, vein and veinlets, have been common either.In addition to stock work zones and thick silicate veins, the presence of diorite and maffic dikes, mineralized grey silicate veins, white silicate, silicate-barite, sulfide, gypsum and calcity are among important phenomena Masjed daghi ore.Petrography studies in 26 doubly polished thin sections and the measurement of geothermometry parameters of 105 primary fluid inclusions were carried out in 6 boreholes in four groups of grey silicate, white silicate, white-grey silicate, and silicate-barite veins.The presence of unknown solid phases, opaque solid phases along with salt phases and eutectic temperature (average of -40.86 Co) of fluid inclusions in Masjed daghi reinforced the necessity of recognizing all phases within fluid inclusions. 10 fluid inclusions were selected based on petrography studies and analyzed by laser Raman spectroscopy method. Laser Raman Spectroscopy was utilized and based on the main peaks of Raman intensity of the minerals such as magnetite, anglesite, malachite, serussite, corundum, orthoclase, anhydriteparagonite, hematite, within fluid inclusions in Masjed daghi area was investigatedKeywords: Raman spectroscopy, fluid inclusion, Alteration, Chemical Phases, Masjed-daghi}
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It was shown that the structure and particle size of zirconia nanoparticles has been controlled through the homogeneous precipitation process by using templates. Hexamine as the template led to ZrO2 nanoparticles with tetragonal structure, whereas coffee extract favored monoclinic structures. Field Emission Scanning electron microscopy (FeSEM), Transmission electron microscopy (TEM) measurements, Infrared and Raman analysis were used to view how the structure may possibly affect their spectrum characteristic. Using these pure m- and t-ZrO2 phases as catalyst, were studied photocatalytic degradation of ciprofloxacin (CIP). Higher degradation efficiency (50%) of the drug was observed at pH5.5 after 15 min using t-ZrO2 phase.Keywords: FT-IR, Monoclinic, Raman spectroscopy, TEM, Tetragonal, ZrO2}
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The current ongoing scientific debate deals with accumulation of hydronium ions (H3O+) on water surface. Elevated interfacial concentration measured by using Raman spectroscopy. A strong surface affinity of H3O+ indicated by Raman spectroscopy under similar conditions. Ion adsorption phenomena, H3O+ formation and its structural activity emphasized in our study. Asymmetric water ion adsorption clearly observed in our research.
Keywords: Raman spectroscopy, Hydronium, Water, Infrared spectroscopy} -
Functionalized Multi-walled carbon nanotubes (f-MWCNTs) which are modified using nitric acid and sulfuric acid were evaluated to synthesize a uniform nanocomposite via application of TiO2. The f-MWCNTs-TiO2 nanocomposites have been produced via using the chemical simple two-step method. To characterize the structural analysis, scanning electron microscopy (SEM) imaging, ultraviolet-visible (UV-Vis) spectroscopy, and Raman spectroscopy were utilized. The maximum shift of D, G, and 2G-bands of f-MWCNTs were related to 20 wt. % f-MWCNTs in TiO2 nanoparticles. Moreover, an up-shift of 40 cm-1 was recorded for the MWCNTs (G’-band) for 5 wt. % f-MWCNTs. For 20 wt. % f-MWCNTs/TiO2 (G-band) nanocomposites, was determined by 4.7%. By increasing the amount of f-MWCNTs in f-MWCNs/TiO2 nanocomposite, the compressive strain was increased. Among the four bonds, the G’-band behaved differently against increasing f-MWCNTs. The shifting frequency of G-band indicates the strong interaction between f-MWCNTs and TiO2 nanoparticles. The interaction between f-MWCNTs and TiO2 nanoparticles identified by the Gruneisen parameter. Therefore, a mechanism generated for stress transfer at the interface between f-MWCNTs and TiO2 nanoparticles which is indicated in many significant increases obtained in the mechanical and acoustical properties.Keywords: Compressive Strain, Multiwalled carbon nanotubes, nanocomposites, Raman spectroscopy, Titanium dioxide}
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زیرلایه های SERS با روش خودساماندهی نانوذرات نقره بر بستر شیشه های عامل دار شده و با استفاده از APTES تهیه شدند. بدین منظور نانوذرات نقره به روش شیمیایی تر ساخته شد و توزیع اندازه آن با استفاده از پراکندگی پویای نوری، 35 نانومتر تعیین شد. از طیف سنجی مرئی-فرابنفش برای مشخصه یابی اپتیکی کلوئید نانوذرات و زیرلایه های تهیه شده استفاده گردید. نتایج نشانگر جابه جایی پیک پلاسمونی به سمت طول موج های بلندتر بعد از خودساماندهی نانوذرات می باشد. تصویر میکروسکوپ الکترونی روبشی توزیع یکنواخت نانوذرات نقره بر سطح شیشه را نشان می دهد. رنگدانه Rhodamine B به عنوان آنالیت برای مطالعه عملکرد زیرلایه در SERS بکار گرفته شد. هرچند در طیف های رامان ثبت شده از پودر و محلول های مولکول ردامین بی RB به دلیل فلورسانس زمینه هیچ سیگنال چشمگیری مشاهده نشد اما با استفاده از زیرلایه تهیه شده و اثرات خاموش کنندگی فلورسانس آن، مدهای رامان این مولکول در محلول 5-10 مولار به وضوح آشکارسازی شدند. با کاهش غلظت محلول به 6-10 مولار، شدت مدهای رامان بسیار کاهش یافت به نحوی که تنها برخی قله ها مشخص می باشند.کلید واژگان: خودساماندهی, ردامین بی, رنگدانه, زیرلایه, طیف سنجی رامان}SERS Investigation of Rhodamine B molecule using self-assembly of nanoparticles on silanized surfaceNano scale, Volume:6 Issue: 2, 2019, PP 46 -52Self-assembly of silver nanoparticles on functionalized glasses via APTES was used to fabricate SERS substrates. For this purpose, silver nanoparticles were synthesized by the wet chemical method and the size distribution of 35 nm was determined, using dynamic light scattering DLS. UV-Vis spectroscopy was used to characterize the optical properties of the colloidal nanoparticles and also the prepared substrate. The results show that the surface plasmon resonance SPR peaks indicate a slight red shift after the self-assembly of nanoparticles. The SEM images showed a uniform distribution of silver nanoparticles on the surface of the glass. Rhodamine B RB dye was used as the analyte for studying substrate performances in SERS. However, no significant signals were observed in the Raman spectra of powder and solutions of the RB molecule due to a fluorescence background but using the prepared substrate and its fluorescence quenching effect, the Raman modes were clearly detected in a 10-5 M solution. By decreasing the concentration of the solution to 10-6 M, the Raman peak intensities were greatly reduced in a way that only some of them were detected.Keywords: Self-assembly, Rhodamine B, Dye, Substrate, Raman spectroscopy}
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International Journal Of Nanoscience and Nanotechnology, Volume:13 Issue: 4, Autumn 2017, PP 359 -366A simple low-cost solvothermal method was applied to synthesize hexagonal wurtzite Cu2ZnSnS4 (CZTS) nanoparticles with different morphologies using Polyvinylpyrrolidone (PVP) as a capping ligand and copper and zinc acetate salts at 180 and 220 ℃. The resulting sphere-like and flower-like nanoparticles synthesized at 180 and 220℃, respectively, indicated thecalculated optical band gaps of 1.45 and 1.28 eV, respectively. Where both samples indicated the metastable wurtzite phase. The main Raman peaks were observed at 333 and 371 cm-1, was indicating the wurtzite phase of CZTS nanocrystals. The phase of the wurtzite CZTS nanoparticles was successfully controlled by using zinc acetate salt, which affected the reaction rate between Zn and S sources. In addition, reaction temperature was found as an effective factor on the morphology, elemental ratio, reaction kinetic, crystallinity, and size of the CZTS nanoparticles. Photoresponse of the CZTS thin films were confirmed by I-V measurements under dark and light illumination. All these results imply the potential of these nanoparticles for solar cell applications.Keywords: Semiconductors, Wurtzite CZTS nanoparticles, Solvothermal method, Raman spectroscopy}
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Multi-walled carbon nanotubes (CNTs) are synthesized with the assistance of water vapor in a horizontal reactor using methane over Co-Mo/MgO catalyst through chemical vapor deposition method. The application of Adaptive Neuro-Fuzzy Inference System (ANFIS) technique for modeling the effect of important parameters (i.e. temperature, reaction time and amount of H2O vapor) on the quality of the CNT process is investigated. Using experimental data, qualities of CNTs are determined for training, testing and validation of developed ANFIS model. From the analysis carried out by the ANFIS-based model, the mean square deviation and a regression coefficient are found to be 4.4% and 99%, respectively. The validation results confirm that the ability of the proposed ANFIS model for predicting the quality of the CNT process over a wide range of operational conditions. In addition, sensitivity analysis indicates that the temperature has the significant effect (i.e. 94%) on the quality of the CNT process.Keywords: ANFIS Modeling, Carbon nanotube, Co-Mo, MgO catalyst, Nanomaterials, Raman spectroscopy}
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در این مقاله، نانوذرات طلا به روش شیمیایی تهیه شده است. خواص اپتیکی این نانوذرات توسط طیف جذب مرئی- فرابنفش، روش روبش-z و طیف سنجی رامان مطالعه شده است. همچنین با استفاده از روش طیف نگاری، ضریب تضعیف جرمی گاما در انرژی های مختلف برای نانوذرات تهیه شده، محاسبه شده اند. طیف جذب مرئی- فرابنفش این مواد، پیک جذبی در محدود 530 نانومتر را نشان می دهد. ضریب شکست غیرخطی و ضریب جذب غیرخطی در شدت 40 میلی وات توسط لیزر نئودیم یگ پیوسته با طول موج nm 532 به کمک چیدمان دریچه بسته و باز روبش-z به ترتیب از مرتبه cm2/W 10-8وcm/W 10-4به دست آمده-اند. به کمک طیف سنجی رامان ارتعاشات شبکه بررسی شده است. اندازه گیری های انجام شده، نشان دهنده تاثیر پرتودهی گاما بر ضریب تضعیف جرمی گاما و خواص اپتیکی نانو ذرات طلا می باشد.کلید واژگان: نانوذرات طلا, خواص اپتیکی, طیف سنجی رامان, روش روبش, z, ضریب تضعیف جرمی, پرتودهی گاما}Au nanoparticles have been synthesis by chemical method. Optical properties of Au nanoparticles have been studied by using UV-Vis and z-scan method and Raman spectroscopy. In addition, the mass attenuation coefficients of the synthesized nanoparticles at different energies were measured by the gamma spectroscopy method. The UV-Vis spectrum of these nanoparticles exhibit an absorption peak at 530 nm region. Nonlinear reflection and nonlinear absorption indexes obtain from close aperture and open aperture z-scan in order of 10-8 cm2/W and 10-4 cm/W were studied with using continue wave Ne: YAG laser λ532 nm by use of closed aperture and open aperture z-scan setup, respectively. The performed measurements show that gamma irradiation affects the mass attenuation coefficient and optical properties of Au nanoparticles.Keywords: Au nanoparticles, Optical properties, Raman spectroscopy, z, scan method, attenuation coefficient, gamma irradiation}
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International Journal Of Nanoscience and Nanotechnology, Volume:11 Issue: 3, Summer 2015, PP 185 -192In this research the composition of polyurethane closed cell (PUCC) with two different concentrations of SiO2 nanoparticles (1.0 and 2.0 wt%) have been prepared. Optical microscopy and SEM imaging, watering uptake, FTIR and Raman spectroscopy of the synthesized samples were carried out. The optical microscopy imaging of samples showed differences in the appearance of matrix produced by applying different concentrations of SiO2 nanoparticles (NPs). The mean cell size of the foams decreased with the addition of SiO2 NPs from 0.0 wt% up to 2.0wt%.Variation in the water uptake of specimens is related to the function of SiO2NPs concentrations. The degree of phase separation and the hydrogen bonding index in samples were evaluated in terms of their FTIR spectroscopy data. The apparent and real densities of foams were measured and then total, open and closed porosity of samples were calculated. With elevating the amount of nanoparticles the open porosity of samples almost increased, while the closed and total porosity decreased. The Raman spectra of the synthesized samples were used for evaluating possible interaction between SiO2 NPs and PUCC foams.Keywords: FTIR, Polyurethane, Raman Spectroscopy, Silica}
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کلوئید نقره سیتراتی با اندازه ی نانوذرات nm 17 به روش لی و میسل فراهم گردید. سپس با استفاده از روش محلولی-ژله ای نانوکامپوزیت نانولوله های کربنی چنددیواره/تیتانیای آلائیده به نانوذرات نقره TiO2 Ag/MWCNTs تهیه شد. با استفاده از دستگاه پتانسیل سنج زتا، اندازه ی نانوذرات نقره زیر nm20 تخمین زده شد. با استفاده از طیف سنجی رامان، درصدهای متفاوتی از نانولوله های کربنی چنددیواره ی عامل دار شده درون بستر تیتانیای آلائیده به نانوذرات نقره ردیابی شد که یکی از عوامل تاثیرگذار بر جابجایی فرکانس نوارهای رامان است. نوار G cm-1 1583 یکی از نوارهای اصلی نانولوله های کربنی در بستر فوق مورد بررسی قرار گرفت و جابجایی آن که تابعی از غلظت نانولوله های کربنی بود بدست آمد. با توجه به میزان جابجایی قله این نوار، کرنش تراکمی نانولوله های کربنی درون این بستر محاسبه گردید که به میزان قابل توجهی بیشتر از مقدار گزارش شده در کارهای مشابه می باشد.کلید واژگان: تیتانیا, طیف سنجی رامان, کرنش تراکمی, نانوذرات نقره, نانولوله های کربنی چنددیواره}Citrate colloidal silver nanoparticles were synthesized with 17 nm by Lee and Meisel technique. TiO2-Ag/MWCNTs nanocomposites were synthesized by sol-gel method. The size of colloidal silver nanoparticles were estimated under 20 nm by Dynamic Light Scattering DLS and Zeta analyzer. By Raman spectroscopic methodology different loading of MWCNTs into TiO2-Ag matrix were scanned in which it is an effective factor in shifting Raman frequencies bands. G band 1583 cm-1 that is one of the main bands of MWCNTs in above matrix, was analyzed and evaluated according to the shift of this band as a function of different loading percentages of MWCNTs. According to the amount of shifting of this band, the compressive strain of MWCNTs in the matrix was calculated that is more remarkable than the amount of the reported values in similar works.Keywords: Ag nanoparticles, MWCNTs, Raman spectroscopy, Compressive strain, Titania}
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Poly (vinylidene chloride) (PVDC) is a barrier polymer which has a wide scope in food packaging industries. A comprehensive study of the normal modes and their dispersion in PVDC using Wilson:s GF matrix method as modified by Higgs is reported. It provides a detailed interpretation of IR and Raman spectra. Characteristic feature of dispersion curves, such as regions of high density-of-states, repulsion, and character mixing of dispersion modes, are discussed. Heat capacity has been calculated in the range 50–500 K via density-of-states using Debye relation. It is in fairly good agreement with the experimental data. Heat capacity behavior of PVDC with temperature was observed nearly linear in nature. Heat capacity provides a relationship between microscopic behavior and a macroscopic property. The thermal stability of a polymeric system and its interactive nature with other properties, such as phonon-phonon coupling is also related to thermodynamic behavior. The present study provides a theoretical framework to understand experimental measurements.
Keywords: Poly (vinylidene chloride), Vibrational dynamics, IR, Raman Spectroscopy, HeatCapacity} -
Nanocrystalline particles of Cerium Oxide (CeO2) have been prepared by the chemical precipitation method using Cerium nitrate and Urea with a molar ratio of 1:2. The results revealed that the formation of CeO2 fine particles is influenced by molar ratio of metal nitrates to fuel. Well faceted CeO2 nanoparticles, were synthesized by thermal-assisted dissociation method at reflux temperature in a short period of time. A possible mechanism for synthesis of such highly pure and stable nanoparticles is tentatively proposed by thermogravimetry-differential thermal analysis (TG –DTA) study. The powders were investigated by X-ray diffraction (XRD), Transmission electron microscopy (TEM), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM). In addition, uniform particles, size distribution and purity of samples are highly dependent on the applied chemical precipitation method. Raman spectroscopy and Electron Diffraction Analysis confirmed the fluorite structure of bulk CeO2.Keywords: Cerium Oxide, Chemical synthesis, Characterization methods, Raman spectroscopy, Transmission electron microscopy (TEM), Optical Properties}
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In this research, tellurium (Te) film with thicknesses of 100- 250 nm were deposited on ceramic substrates by thermal evaporation at 373 K. The thickness of the film was determined by Rutherford backscattering spectroscopy. The influence of the thickness on the structural, morphological and molecular bonds was characterized using XRD, scanning electron microscope, and Raman spectroscopy. The XRD results confirmed that increasing the thickness, increased the intensity of the peaks, indicating increased crystallinity. SEM images indicated that the density of the film and holes in the film decreased as thickness increased. The Raman spectrum revealed that the TeO2 molecular bond formed on the surface only at room temperature up to 100 nm in thickness; as thickness increased, this bond was observed at 323 K.Keywords: Tellurium, Thermal evaporation, Raman spectroscopy, RBS}
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