The interactions of water with the polar headgroups in the reversed micelles of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium bis(2-ethylhexyl) phosphate (NaDEHP) have been studied by means of Fourier transform infrared spectroscopy (FT-IR). O−H stretching bands of water in both systems varied with water content (W 0, the molar ratio of water to surfactant). When W 0 increased from 1 to 20, the O−H stretching frequency shifted from 3493 to 3416 cm-1 in AOT formed reverse micellar system and from 3385 to 3417 cm-1 in NaDEHP system, approaching the frequency of the bulk water. As a response to water solubilization, frequency decreases of sulfonate and phosphate stretching mode in AOT and NaDEHP reverse micellar solutions have also been observed, indicating hydrations of the two surfactants. Results showed that the water molecules encapsulated in reversed micelles are similar to that in the bulk form when W 0 > 16 in AOT system and W 0 > 12 in NaDEHP system. In addition, the splitted peaks of the asymmetric sulfonate stretching band were found shifting to lower frequencies upon hydration, due to the weakening of the sodium−sulfonate interaction after hydration and an associated increase in their spatial separation.

FT-IR spectroscopy has been utilized to study nylon 66/lithium salt systems. The results show that coordination between nylon 66 and lithium ions brings about significant variation in the FT-IR spectra: (1) a stronger hydrogen bond is formed in the systems; (2) the interaction induces obvious conformational changes of the nylon 66 chains. A coordination model has been proposed to rationalize the observed spectral phenomena. The interaction between amide groups and lithium ions is a feasible approach to modify the performance of nylon 66.

The study of the sugar-metal ion interactions remains one of the main objectives of carbohydrate coordination chemistry because the interactions between metal ions and carbohydrates are involved in many biochemical processes. This paper presents a comparison of coordination structures of erythritol with alkaline-earth-metal and lanthanide chloride and nitrate in the solid state using FT-IR and X-ray diffraction. Neutral, nondeprotonated erythritol (E) reacts with CaCl(2) to give three CaCl(2)(-)erythritol (CaE(I), CaE(II), CaE(III)) complexes, showing that three of the five general features of calcium-carbohydrate complexes deduced in the reference encounter contrary examples. Different coordination structures have been observed for calcium and lanthanide chloride and nitrates. The coordination of carbohydrates to metal ions is complicated, and erythritol, chloride ions, nitrates, water molecules, and ethanol (crystallization medium and reaction solvents) have the chance to coordinate to metal ions. IR spectral results show that different lanthanide ions, from LaCl(3) to TbCl(3), have similar coordination structures with erythritol. The results show that erythritol can act as two bidentate neutral ligands (CaE(I), CaE(II), CaE(III), CaEN, PrE, NdE) or as a three-hydroxyl donor (NdEN). The IR results are consistent with the crystal structures.

Background: Fourier transform infrared (FT-IR) spectroscopy is an effective tool for investigation of chemical changes at the molecular level. We previously demonstrated that FT-IR spectroscopy can reliably distinguish multiple types of carcinoma from healthy tissue. Because various stomach diseases are common, it is important to explore a noninvasive and rapid method to detect malignancy and gastritis in endoscopic biopsies. Our aim was to classify endoscopic biopsies into healthy, gastritis, and malignancy through the use of FT-IR spectroscopy. Methods: A total of 103 endoscopic samples, including 19 cases of cancer, 35 cases of chronic atrophic gastritis, 29 cases of chronic superficial gastritis, and 20 healthy tissue samples, were obtained at the First Hospital of Xi'an Jiaotong University, China. A modified attenuated total reflectance accessory was linked to a WQD-500 FT-IR spectrometer for biopsy measurement. The spectral characteristics for different types of tissues were correlated with the corresponding pathology results. The gastric biopsies were classified by FT-IR spectroscopy and a discriminant analysis method. Results: There were significant differences in the FT-IR spectra of four types of gastric biopsies. The discriminant analysis results demonstrated that the sensitivity of FT-IR detection for healthy, superficial gastritis, atrophic gastritis, and gastric cancer was 90%, 90%, 66%,

The results indicate that FTIR may be used in clinical diagnosis.