J-aggregation of 3,3-disulfopropyl-5,5-dichlorothiacyanine dye on colloidal silver particles with different properties

Наночестице сребра коришћене у овој докторској дисертацији синтетисане су у воденој средини помоћу различитих редукционих средстава, као што су натријум-борхидрид, тринатријум-цитрат и цетил-триметил-амонијум-бромид. Употребом ових метода добијене су наночестице сферног и штапићастог облика различитих величина и површинске покривености...Silver nanoparticles in aqueous solution were synthesized by reduction of silver nitrate using various reducting agents such as sodium borohydride, trisodium citrate and cetyl trimethyl ammonium bromide. Silver nanospheres and nanorods with a different size and surface coverage were obtained. Silver colloidal sol was characterized using various experimental methods: transmission electron microscopy, UV-vis spectroscopy, fluorescence and Raman spectroscopy, atomic force microscopy, dynamic light scattering, and zeta potential measurements. The interaction between synthesized silver nanoparticles and anionic cyanine dye (3,3’-disulfopropyl-5,5’-dichlorothiacyanine dye, TC) in aqueous solution was studied..

Synthesis and crystal structure of Ca0.9Er0.1MnO3

Ca0.9Er0.1MnO3 nanopowders with perovskite type crystal structure were synthesized by sucrose-nitrate procedure (SNP). SNP is a combustion method in which sucrose C12H22O11 was used as fuel, while calcium nitrate tetrahydrate Ca(NO3)2×4H2O, manganese(II) nitrate hydrate Mn(NO3)2×H2O, erbium(III) nitrate pentahydrate Er(NO3)3×5H2O were used as oxidants. Obtained powder Ca0,9Er0,1MnO3 were calcinated at a temperature between 800–1000 °C. Powder properties have been studied, such as crystallite and particle size, lattice parameters, structural changes, and specific surface area. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and Brunauer-Emmet-Teller (BET) method were used to characterize the synthesized samples at room temperature. Also, high temperature treatment (up to 1000 °C) was used to follow the stability of solid solutions and the growth of crystallites

Surface enhanced Raman spectroscopy of thiacyanine dye J-aggregates on single silver nanoaggregates

Dye-coated colloidal metal nanoparticles (NPs) exhibit interesting optical properties originating from the interaction between metal core and dye shell. Depending on the interaction mechanism between the two, optical properties of dyes or NPs can be changed separately or jointly within the dye-NP assembly [1]. Many of the recent studies are focused on dyes which are able to self-assemble in highly oriented structures called Jaggregates on the surface of metallic NPs [2,3]. Owing to the variety of mechanisms by which dyes and their J-aggregates can interact with metallic NPs, dye-NP assemblies can lead to applications ranging from nanoscale sensing [4] to advanced composite materials for novel active and nonlinear optical devices [5]. Here we study the influence of TC concentration on its J-aggregation on the surface of AgNPs assemblies using Raman mapping and atomic force microscopy (AFM). Aqueous solutions (colloids) of citrate stabilized AgNPs with an average diameter of ~10 nm are mixed with TC dye solution and then deposited onto freshly cleaved highly oriented pyrolytic graphite and mica surfaces. The spectral signature of citrate ions is identified by (i) the O-H band around 220 cm-1, (ii) the C-H band around 2950 cm-1 and (iii) pronounced blinking in the 1000-1800 cm-1 range. In contrast, dye molecules adsorbed on nanoparticles are recognized by several stable Raman bands between 200 and 1600 cm-1. In situ AFM measurements show that SERS 'hot spots' are formed either on large single nanoparticles (diameter > 100 nm) or within assemblies of small nanoparticles (with diameters in the 10 - 50 nm range). However, only the latter are found to yield a citrate or TC dye SERS signal. We find that the TC dye adsorbed on the surface of AgNP nanoassemblies always forms J-aggregates when the dye concentration in the TC-AgNP solution is varied between 0.5μM and 17μM. Even though, a clear SERS spectra of dye Jaggregates can be acquired for high dye concentration (17μM) the citrate ions always exist on the AgNP surface and so does their SERS signature in form of O-H (220 cm-1) and C-H (2960 cm-1) bands. Assemblies with low TC concentration (0.5μM) do not have a clear dye SERS spectra, but rather spectra similar to the one of citrate ions meaning that either not all AgNPs are dye coated, or rather that the amount of TC molecules adsorbed on the surface of the nanoparticle is small and hence not detectable. We are grateful to the Serbian Ministry of Education, Science and Technological Development for financial support through projects Nos. OI 171005, OI 172023. This work was performed in the context of the European COST Action MP1302 Nanospectroscopy.V International School and Conference on Photonics and COST actions: MP1204, BM1205 and MP1205 and the Second international workshop "Control of light and matter waves propagation and localization in photonic lattices" : PHOTONICA2015 : book of abstracts; August 24-28, 2015; Belgrad

TEM and DFT study of Indocyanine green adsorption on a silver nanoparticle surface

U ovom radu, transmisionom elektronskom mikroskopijom (TEM) i teorijskim proračunom (DFT), izučavana je adsorpcija boje Indocijanin zeleno (ICG) na površini nanočestica srebra (AgNPs). Studija je pokazala da su dobijene hibridne nanočestice sastava Ag-jezgro-ICG-omotač. TEM merenjima potvrđeno je formiranje omotača boje oko AgNPs debljine ~ 3 do 4 nm, dok su HRTEM merenja pokazala mikrostrukturne promene AgNPs usled adsorpcije boje ICG. Teorijskim proračunom utvrđeno je da se molekul ICG boje vezuje kovalentno za atom Ag, na površini AgNPs, preko svoje SO3− grupe.Here we present the TEM and DFT study of hybrid nanoparticles consisting of an Ag core and Indocyanine green (ICG) shell. TEM measurements revealed the formation of a distinctive ~ 3 to 4 nm thick halo around the particles, while HRTEM measurements show microstructural changes in NPs. The DFT calculations were used to investigate the energetics of interaction between ICG molecule and Ag-surface. The obtained data indicate a strong interaction between Ag-atom from NPs surface and SO3− group of ICG molecule.59th Meeting of the Serbian Chemical Society; June 1-2, 2023, Novi Sad, Serbi

Synthesis and characterization of nanostructured Ca0.9Er0.1MnO3

Nanostrukturni Ca0.9Er0.1MnO3 je sintetisan saharoza-nitratnon procedurom (SNP). Tokom ove metode sagorevanja su korišćene sledeće hemikalije: saharoza C12H22O11 koja ima dvostruku ulogu i goriva i kompleksanta, kalcijum-nitrat tetrahidrat, mangan(II)-nitrat hidrat i erbijum(III)-nitrat pentahidrat. Nitrati metala i saharoza su kombinovani u njihovim odgovarajućim stehiometrijskim odnosima da bi se pripremio složeni oksid perovskitske nanostrukture. Dobijeni prah Ca0.9Er0.1MnO3 je kalcinisan u temperaturnom opsegu od 800-1000°C tokom 15 min. Ispitani su veličina čestica, parametri rešetke, strukturne promene i površina. Za karakterizaciju sintetisanih uzoraka korišćena je diferencijalno termijska analiza (DTA), rendgenska difrakciona analiza (XRD), Furijeova transformaciona infracrvena spektroskopija (FTIR) i skenirajuća elektronska mikroskopija (SEM).Nanostructured Ca0.9Er0.1MnO3 was synthesized by the sucrose-nitrate procedure (SNP). During this combustion method, sucrose C12H22O11 which is both fuel and complexant and metal ions in the form of calcium nitrate tetrahydrate, manganese(II) nitrate hydrate, erbium(III) nitrate pentahydrate were used. Metal nitrates and sucrose were combined to prepare this nanostructured in their appropriate stoichiometric ratios. Obtained Ca0,9Er0,1MnO3 powder was calcined in a temperature range of 800-1000 °C for 15min. Particle size, lattice parameters, structural changes, and specific surface area were investigated. DTA, X-ray diffraction (XRD), FTIR, and Field emission scanning electron microscopy (SEM) were used to characterize the synthesized samples at room temperature.59th Meeting of the Serbian Chemical Society; June 1-2, 2023, Novi Sad, Serbi

Preparation of Ca0.9Er0.1MnO3 nanopowders by combustion method

Program and book of abstracts / 2nd International Conference on Innovative Materials in Extreme Conditions i. e. (IMEC2024), 20-22 March 2024 Belgrade, Serbia

Synthesis and characterization of quercetin-conjugated gold nanoparticles

Gold nanoparticles and quercetin-conjugated gold nanoparticles complex were synthesized using trisodium citrate as reducing agent. Both kinds of nanoparticles were characterized using spectrophotometry, dynamic light scattering and zeta potential measurements. Comparison of the results confirmed successful synthesis of quercetin-conjugated gold nanoparticles complex.Physical chemistry 2018 : 14th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 2018

Investigation of nanostructured Ca0.9Er0.1MnO3 obtained by sucrose nitrate procedure

Nano-crystalline Ca0.9Er0.1MnO3 oxide with a perovskite structure was synthesized by the sucrose nitrate procedure (SNP), with the help of sucrose, which plays the role of fuel and complexant. Other chemicals used are calcium nitrate tetrahydrate Ca(NO3)2×4H2O, manganese nitrate hydrate Mn(NO3)2×H2O, erbium nitrate pentahydrate Er(NO3)3×5H2O. Metal nitrates and sucrose were mixed in stoichiometric ratios, in order to obtain a perovskite with a crystalline structure. The resulting Ca0.9Er0.1MnO3 is calcined for 15 minutes in the temperature range from 800°C to 1000°C. Diffraction thermal analysis (DTA), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and inductively coupled plasma ICP were used to characterize the obtained powder

Preparation, synthesis and characterization of nanometric Ca0.9Er0.1MnO3

The present research demonstrates the synthesis and characterization of Ca0.9Er0.1MnO3 perovskite powder using the sucrose nitrate procedure (SNP) technique. The following substances were used to obtain this complex perovskite: sucrose C12H22O11, which has a dual role (complexant and fuel), and metal nitrates were used as oxidants - calcium nitrate tetrahydrate Ca(NO3)2×4H2O, manganese(II) nitrate hydrate Mn(NO3)2×H2O, erbium(III) nitrate pentahydrate Er(NO3)3×5H2O. Nanopowder was prepared by combining metal nitrates in their respective stoichiometric ratios. The synthesized Ca0.9Er0.1MnO3 powder was calcined in a temperature range of 800–1000 °C for a period of 15 min. The effects of calcination were characterized through different experimental techniques (differential thermal analysis (DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), and inductively coupled plasma (ICP))

Effect of Thermal Treatment on Spectroscopic and Morphological Properties of Co0.9Ho0.1MoO4 Nanopowders

Najlakši i najefikasniji metod prihvatljiv za kontrolu sastava i morfologije Co0.9Ho0.1MoO4 je metoda glicin nitrata (GNP), koja je korišćena za sintezu nanostrukturiranog praha. To je obećavajući metod za kontrolu stehiometrije, homogenosti i čistoće postignute procesom sagorevanja. Metalni nitrati i glicin su pomešani u odgovarajućim stehiometrijskim odnosima da bi se pripremio tehnološki važan nanostrukturirani Co0.9Ho0.1MoO4. Uzorci dobijeni pomenutom metodom dalje su podvrgnuti različitim metodama karakterizacije kao što su DTA, rendgenska difrakcija (XRD), infracrveni spektar Furijeove transformacije (FT-IR), spektroskopija i emisiona skenirajuća elektronska mikroskopija (FESEM). Dobijeni nanoprah je pokazao visok nivo anizotropije oblika i veličine čestica u obliku aglomerata. Takođe, primetne su razlike u mikrostrukturi i pločastim kristalima. Boja sintetizovanog uzorka se posle termičkih tretmana menja iz tamnijih u svetlije nijanse. Zbog koncentracije Co dolazi do izraženih promena dominantne talasne dužine (nm) i čistoće boje između početnog uzorka i uzorka nakon zagrevanja (1100 oC).The easiest and most effective method acceptable for controlling the composition and morphol- ogy of Co0.9Ho0.1MoO4 is the glycine nitrate method (GNP) by which the nanostructured powder was synthesized. It is a promising method for controlling the stoichiometry, homogeneity, and purity achieved by the combustion process. Metal nitrates and glycine were mixed in appropriate stoichio- metric ratios to prepare technologically important nanostructured Co0.9Ho0.1MoO4. The samples ob- tained by the mentioned method were further subjected to different characterization methods such as DTA, X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), spectroscopy, and emis- sion scanning electron microscopy (FESEM). The resulting nanopowder showed a high level of ani- sotropy of the shape and size of particles in the form of agglomerates. Also, differences in microstruc- ture and plate-like crystals are noticeable. The color of the synthesized sample changes from darker to lighter shades after thermal treatments. Due to the concentration of Co, there are pronounced changes in the dominant wavelength (nm) and color purity between the initial sample and the sample after heating (1100 oC).Procesing '24 : 37. Međunarodni kongres o procesnoj industriji : zbornik radova - Proceedings, 29-31. maj 2024, Beogra