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We examine the application of an oscillating cell in combination with right-angle Raman scattered light collection geometry for quantitative Surface Enhanced (Resonance) Raman Scattering (SER(R)S) measurements from nano-colloidal noble metal solutions. This excitation/collection Raman configuration allows specific SERS and SERRS signatures of aqueous solutions of mitoxantrone, an antitumor drug, to be easily resolved at (sub)-ng/mL and (sub)-pg/mL concentration levels. A partial least-squares (PLS) chemometric algorithm was applied to predict the concentration of 25 microL of aqueous solutions of mitoxantrone added in 0.5 mL of a silver colloidal solution in a test tube attached to the oscillating cell. For SERS (514.5 nm) measurements, this was performed over the range from 0 to 13 ng/mL with a correlation coefficient R(2) of 98.5% and RMS error of prediction equal to 0.5 ng/mL. SERRS (632.8 nm) measurements performed over a range of 0 to 7 pg/mL gave R(2) = 98.92% and RMSE = 0.2 pg/mL.

Quantitative analysis of methylene blue (MB) has been performed with Surface Enhanced Raman Scattering, SERS, using citrate reduced silver colloid activated with NaCl. In this study, the combination of SERS occurring at the proximity of the plasmon surface and of resonance Raman with excitation wavelength matched to the maximum absorbance of the molecule being analyzed, was successfully applied to maximize the Raman scattering intensity. The surface‐enhanced resonance Raman scattering (SERRS) spectra of aqueous solutions of the dye at various concentrations were collected in right‐angle scattering geometry configuration which results favorable when nanocolloidal dispersions are used. The MB concentration was correlated with the intensity of the peak centered at 1,625 cm−1 in the SERRS spectrum and this correlation resulted in an extremely sensitive quantitative investigation of the MB with limit of detection in pM level. Among others, this method can be easily applied for the examination of both the selectivity of waste water purification membranes for relevant small molecular weight contaminants or/and the solar photocatalytic effectiveness of such membranes for the degradation of pertinent pollutants by their quantitative assessment in the permeate at very low concentration range.

The goal of this work is to model the nature of the chemical species [CdCl2(extractant)2] that are formed during the solvent (or liquid-liquid) extraction of the toxic cadmium(II) from chloride-containing aqueous media using hydrophobic 2-pyridyl ketoximes as extractants. Our coordination chemistry approach involves the study of the reactions between cadmium(II) chloride dihydrate and phenyl 2-pyridyl ketoxime (phpaoH) in water-containing acetone. The reactions have provided access to complexes [CdCl2(phpaoH)2]∙H2O (1∙H2O) and {[CdCl2(phpaoH)]}n (2); the solid-state structures of which have been determined by single-crystal X-ray crystallography. In both complexes, phpaoH behaves as an N,N’-bidentate chelating ligand. The complexes have been characterized by solid-state IR and Raman spectra, and by solution 1H NMR spectra. The preparation and characterization of 1∙H2O provide strong evidence for the existence of the species [CdCl2(extractant)2] that have been proposed to be formed during the liquid-liquid extraction process of Cd(II), allowing the efficient transfer of the toxic metal ion from the aqueous phase into the organic phase.

Electrical relaxation and conductivity processes in amorphous and semicrystalline poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) homopolymers and certain PET/PEN copolymers have been studied by means of dielectric spectroscopy. Homopolymers and copolymers able to crystallize were subjected to successive thermal runs to investigate the influence of the thermal history upon the morphology and the electrical behavior of the polymeric systems. The morphology of the untreated as well as the heat‐treated specimens was determined by means of Differential Scanning Calorimetry (DSC). All samples exhibit β‐relaxation process, due to local motions of the CO polar side groups, and α‐relaxation process associated to the glass/rubber transition. In the PEN spectrum an additional, subglass, mode was recorded, most probably attributed to cooperative motions of the naphthalene groups. Finally, the dynamic nature of the crystallization process is expressed via the over glass transition mode and the temperature dependence of dc conductivity recorded in amorphous PET, PEN, and PET/PEN (85/15) (wt/wt) samples. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3078–3092, 2006

The surface enhanced Raman scattering spectroscopy (SERS) is introduced as a new method to probe the initial release of active agents from controlled delivery systems. As a model system, mitoxantrone‐loaded polypropylene specimens immersed in water have been utilized. Surface enhanced resonance Raman scattering (SERRS) measurements allowed the quantitative delineation of the initial drug release profile. SERRS was also compared in early stage release processes with UV–vis absorption often used in traditional quantitative analysis via HPLC, a common technique for controlled release evaluation. More and above the high selectivity of the Raman Effect, SERS has been proved as a highly sensitive method to quantitatively monitor the initial release of the medicine even at the very early stage of the delivery process; UV–vis absorbance was unable to respond accordingly. Copyright © 2012 John Wiley & Sons, Ltd.

Our results suggest crosslinking reaction in ICRS material. This should be taken into consideration prior to any CXL treatment of post ICRS-implanted cornea.

The modification of cotton fabrics with water-soluble cationic copolymers for salt-free dyeing applications with reactive dyes is explored in the present work. To this end, a family of bifunctional water-soluble cationic copolymers was designed through the chemical modification of poly(4-vinyl benzyl triethylammonium chloride), PVBC, with triethylamine, TEAM. These copolymers were applied onto cotton fabrics in aqueous alkaline solutions at moderate temperature (60oC). The successful cotton modification was verified through the characterization of the modified samples with Raman and XPS spectroscopy. Moreover, a polymer coverage of the fabric of the order of 0.1% (w/w) was estimated following the polymer exhaustion through UV-vis spectroscopy of the aqueous solutions used for the modification. The modification kinetics were followed through the evolution of the Raman spectra of the modified fabrics, the polymer exhaustion of the aqueous modification solutions and, indirectly, the dye exhaustion of the dyebaths using a reactive dye, namely Novacron Ruby NRS-3B. All techniques claim that fabric modification is practically accomplished within the first 1-2h. The double functionality of the copolymers was explored through the XPS study of the modified fabrics, revealing that both electrostatic binding and covalent bonding of the cationic copolymers with the anionic surface of the fabric are expected to take place. As an important consequence, the polymer-modified fabrics are strongly dyed under eco-friendlier conditions, namely in salt-free alkaline solutions at room temperature, in contrast to the barely dyed unmodified fabric. Graphical Abstract