Spectroscopic Characterization of Emulsions Generated with a New Laser-Assisted Device

Abstract

This paper presents a spectroscopic study of emulsions generated with a laser-assisted device. Fourier transform infrared (FTIR), Raman and UV–Vis–NIR reflectance spectra of emulsions, recorded before and after exposure to laser radiation were used to characterize the effect of laser irradiation. The paper also presents a comparison between the calculated IR spectra and the experimental FTIR spectra of an emulsion’s components. FTIR measurements allowed the identification of absorption bands specific to each of the emulsions’ components. Moreover, it enabled the observation of destabilization of the emulsion in real-time. Raman spectroscopy allowed the observation of the modifications at a molecular level, by identifying the vibrations of the representative functional groups and the polymerization of sodium tetradecyl sulfate (STS) molecules by analyzing the evolution of the carbonyl band. UV–Vis–NIR reflectance spectra of emulsions before and after exposure to laser radiation showed that the physical characteristics of the emulsions changed during irradiation—the dimensions of the droplets decreased, leading to an emulsion with a better time stability. These results proved that the employed spectroscopy techniques were powerful tools in emulsion analysis.

Targeted Hybrid Nanocarriers as a System Enhancing the Skin Structure

“…The IR analysis shows that there are no spectral differences between empty formulations and formulations enriched with levan nanoparticles or nanoemulsion ( Figure 1 ). This observation proves that there are not any side processes after adding ingredients to the matrix and the matrix remains stable [ 25 ]. For all three types of formulation, the most intensive signals are connected with water molecule oscillation (~3000–3700 cm −1 ) and the presence of alcohols like glycerol, propylene glycol (hydroxyl group oscillations ~1500 cm −1 ).…”

Spectral Properties of Foams and Emulsions

“…UV-Vis-NIR reflectance spectra of sodium tetradecyl sulfate (STS) in water and oily vitamin A emulsions showed an increase in reflectance after the sample was exposed to laser radiation, suggesting a decrease in size of the droplets (Figure 6). This finding was supported by surface tension analyses, optical spectroscopy analyses and dynamic light scattering measurements of the emulsions before and after laser irradiation [150,159]. UV-Vis absorbances recorded at two wavelengths (450 nm and 850 nm) were employed to evaluate the stability of W/O emulsions, using the turbidity ratio method.…”

Dihydroartemisinin-Loaded Chitosan Nanoparticles Inhibit the Rifampicin-Resistant Mycobacterium tuberculosis by Disrupting the Cell Wall

“…DHA, CS NPs, and DHA-CS NPs were aqueous solutions, so the results of FTIR were significantly affected by the characteristic peaks of water. In Figure 2, the bands near 3354.0 cm −1 and 1639.0 cm −1 are ascribed to the characteristic hydroxyl peaks of adsorbed water (Dinache et al, 2020). The absorption peak intensity of CS NPs and DHA-CS NPs near 1639.0 cm −1 was significantly stronger than that of DHA and presented the stretching vibration of C = O in amide bond, indicating the successful crosslinking interaction between TPP and the amino groups of CS within CS NPs (Ye et al, 2015).…”