Search results for "Rhodamine B"
showing 10 items of 30 documents
Rhodamine (B) photocatalysis under solar light on high crystalline ZnO films grown by home-made DC sputtering
2018
Abstract ZnO thin films were deposited by home-made DC sputtering of zinc target under mixed gases (Argon, Oxygen) plasma on glass substrates. Films were deposited by varying oxygen partial pressure (PO2) from 0.09 to 1.3 mbar in the deposition chamber, at a fixed substrate temperature of 100 °C. The samples were characterized by photoluminescence (PL), X-ray diffraction (XRD), optical transmissions (UV–vis), scanning electron microscopy (SEM) and electrical (Hall effect) measurements. The results indicate that by varying the oxygen pressure in the deposition chamber, the films show a precise and well defined photoluminescence emissions for each range of pressure covering almost the entire …
Applications of confocal laser scanning microscopy to dental bonding.
1998
The introduction of confocal laser scanning microscopy (CLSM) has provided a valuable new technique for the visualization of bonding structures such as a hybrid layer in dentin (Watson, 1989, 1991), In the case of seven commercially-available dentin bonding systems, it could be demonstrated that the CLSM renders considerably more detailed information than the SEM because of its nondestructive nature and because of the possibility of a distinction between components of bonding agents. With most of the bonding systems, measurements of the thickness of the hybrid layer could be carried out when the primer component was labeled with rhodamine B. It was found that this thickness is significantl…
Visible light photocatalytic activity of macro-mesoporous TiO2-CeO2inverse opals
2018
Macro-mesoporous TiO2 inverse opal materials were synthesized and they were tested as photocatalysts under visible light irradiation. The influence of cerium oxide addition towards the Rhodamine B (RhB) photodegradation activity was evaluated. Structural, textural, spectral and surface properties of the TiO2-CeO2 inverse opal nanocomposites were studied by XRD, XPS, SEM, TEM, N2 adsorption-desorption, Diffuse Reflectance UV–vis and Photoluminescence spectroscopies. Compared to commercial TiO2 anatase, the macro-mesoporous TiO2 inverse opal exhibited six times higher kinetic rate constant in the RhB degradation under visible light irradiation. The good photocatalytic activity was related to …
Effect of the addition of different doping agents on visible light activity of porous TiO2 photocatalysts
2018
Abstract The influence of the addition of different doping agents (N, W and Hf) on the macroporous TiO2 photoactivity toward the Rhodamine B degradation and ethanol photo-oxidation was evaluated. The samples were characterized by XRD, XPS, SEM, TEM, N2 adsorption-desorption, UV–vis Diffuse Reflectance and Photoluminescence spectroscopies to study also the changes in the physico-chemical properties due to the presence of dopants. The photonic effect and the high ordered porous structure of the macroporous TiO2 that lead to increase the path length of the light, were the key factors that allow to enhance the catalytic activity towards the dye and VOC degradation under visible and solar light …
On Pathways for Small Molecules Into and Out of Human Hair Fibers
1996
This paper represents an experimental approach of histology of the human hair fiber in dyeing and diffusion phenomena and its contribution to the interpretation of hair analysis results for drug abuse. Rhodamine B was applied to human hair fibers from either aqueous solution or methanol/ethanol solvent. The experiments were performed on natural hair of different ethnic groups as well as on extensively bleached hair strands. The microscopical study of the pathway of diffusion of rhodamine B into the hair fibers indicated that the reagent had entered the unmodified fibers at the scale edges between the cuticle cells. At the beginning of the diffusion process intercellular diffusion was the pr…
Dye-Labeled Poly(organosiloxane) Microgels with Core−Shell Architecture
1999
Poly(organosiloxane) microgels are highly cross-linked rather monodisperse spherical particles of radius about 10 nm. Using a functionalized silane comonomer, i.e., (chlorobenzyl)trimethoxysilane, model particles suitable for studies in colloid physics are available: photoreactive and fluorescent dyes can be covalently bound within the microgels to prepare tracers for diffusion studies using forced Rayleigh scattering (FRS) and fluorescence correlation spectroscopy (FCS). For the application as tracer particles, it is important not to influence the diffusion behavior by the coupled chromophores. Therefore, functionalized precursors with a core−shell architecture are used to minimize labeli…
Amphiphilic poly(hydroxyethylaspartamide) derivative-based micelles as drug delivery systems for ferulic acid
2008
Self-assembling micelles, potentially useful as drug delivery systems for ferulic acid (FA), were obtained in aqueous media from amphiphilic alpha,beta-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) copolymers bearing at the polyamino acidic backbone both poly(ethyleneglycol) (2000 or 5000 Da) and hexadecylamine (C(16)) moieties, at a concentration of 7 x 10(- 3) and 4 x 10(- 3) g/l, respectively, with nanometre size and negative zeta potential. These micelles were able to entrap FA and to release it in a prolonged way in phosphate buffer solution at pH 7.4 and human plasma. These systems were also stable in storage conditions and have no cytotoxic effects on Caco-2, 16 HBE, HuDe and K562 cel…
Environmentally Friendly Eutectogels Comprising l-amino Acids and Deep Eutectic Solvents: Efficient Materials for Wastewater Treatment.
2020
Current concerns for sustainability and the environment make low-impact materials desirable for environmental remediation and, in particular wastewater treatment. We obtained supramolecular gels of l-amino acids in the deep eutectic solvent formed by choline chloride and phenylacetic acid. After gel characterization, and investigating gel-sol transition temperatures, gelation kinetics, rheological properties, and morphology, the gels were applied as sorbents to remove cationic dyes from aqueous solutions. The effects of the pH, dye nature, volume, and concentration of wastewater were analyzed, and the best result was obtained with a l-phenylalanine-based eutectogel. It can be reused for at …
Antibody-Capped Mesoporous Nanoscopic Materials: Design of a Probe for the Selective Chromo-Fluorogenic Detection of Finasteride
2012
[EN] The synthesis of capped mesoporous silica nanoparticles (MSN) conjugated with an antibody (AB) as a gatekeeper has been carried out in order to obtain a delivery system able to release an entrapped cargo (dye) in the presence of a target molecule (antigen) to which the conjugated antibody binds selectively. In particular, MSN loaded with rhodamine B and functionalized on the external surface with a suitable derivative of N-(t-butyl)- 3-oxo-(5a,17b)-4-aza-androst-1-ene-17-carboxamide (finasteride) have been prepared (S1). The addition of polyclonal antibodies against finasteride induced capping of the pores due to the interaction with the anchored hapten-like finasteride derivative to g…
POLYASPARTAMIDE-POLYLACTIDE GRAFT COPOLYMERS WITH TUNABLE PROPERTIES FOR THE REALIZATION OF FLUORESCENT NANOPARTICLES FOR IMAGING
2015
Here, the synthesis and the characterization of novel amphiphilic graft copolymers with tunable properties, useful in obtaining polymeric fluorescent nanoparticles for application in imaging, are described. These copolymers are obtained by chemical conjugation of rhodamine B (RhB) moieties, polylactic acid (PLA), and O-(2-aminoethyl)-O'-methyl poly(ethylene glycol) (PEG) on α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). In particular, PHEA is first functionalized with RhB to obtain PHEA-RhB with a derivatization degree in RhB (DDRhB ) equal to 0.55 mol%. By varying the reaction conditions, different amounts of PLA are grafted on PHEA-RhB to obtain PHEA-RhB-PLA with DDPLA equal to 1.9, 4…