A new method for rapid determination of carbohydrate and total carbon concentrations using UV spectrophotometry.

Fluorescence and Phosphorescence Spectroscopy: Physicochemical Principles and Practice

Removal of beta-blockers from aqueous media by adsorption onto graphene oxide.

Aragonite–calcite–vaterite: A temperature influenced sequential polymorphic transformation of CaCO3 in the presence of DTPA

Removal of Safranin dye from aqueous solution using magnetic mesoporous clay: Optimization study

Polymorphism in CaCO3 — Effect of temperature under the influence of EDTA (di sodium salt)

Excimer formation in inclusion complexes of β-cyclodextrin with salbutamol, sotalol and atenolol: Spectral and molecular modeling studies

The absorption and fluorescence spectra of sulphadiazine (SDA), sulphisomidine (SFM) and sulphanilamide (SAM) have been analysed in different solvents, pH and β-cyclodextin. The inclusion complexes of the above sulphonamides with β-CD were investigated by UV–Vis, fluorometry, DFT, FT–IR and 1H-NMR. The solvent study shows that the absorption and emission maxima of the SDA and SFM are more red-shifted than SAM molecule. In non-aqueous solvents, a single fluorescence band (340 nm) is observed, whereas in water and β-CD solutions, dual emission (at 340 and 430 nm) is noticed for SDA and SFM molecules. The dual emission is due to twisted intramolecular charge transfer band (TICT). Studies on β-CD solutions reveal that (1) sulphonamides form 1 : 1 inclusion complex with β-CD; and (2) the red-shift and the presence of TICT in the β-CD medium confirm that the heterocyclic ring is encapsulated in the hydrophobic part and aniline ring is present in the hydrophilic part of the β-CD cavity.

Spectral characteristics of sulphadiazine, sulphisomidine: effect of solvents, pH and β-cyclodextrin

Polymorphic compositions of CaCO3 synthesized under the influence of a blended system of EDTA and HEDP between 60 and 230 °C using a controlled precipitation technique from CaCl2 solution using Na2CO3 has been investigated. The phases and structures of the samples were characterized by Raman, FTIR, and powder XRD techniques. The morphological studies were carried out using SEM, field emission scanning electron microscope (FESEM), and TEM. Usually, at higher temperatures vaterite and aragonite are transformed into stable calcite. Here, we report the stabilization of metastable aragonite and vaterite in the presence of a blended system of EDTA and HEDP at 200 and 230 °C. We also report a novel morphology, roselike structure for vaterite at 230 °C, which is not reported earlier.

V.K. Subramanian

Papers

Aragonite–calcite–vaterite: A temperature influenced sequential polymorphic transformation of CaCO3 in the presence of DTPA

Polymorphism in CaCO3 — Effect of temperature under the influence of EDTA (di sodium salt)

Excimer formation in inclusion complexes of β-cyclodextrin with salbutamol, sotalol and atenolol: Spectral and molecular modeling studies

Spectral characteristics of sulphadiazine, sulphisomidine: effect of solvents, pH and β-cyclodextrin

Synergistic Effect of EDTA and HEDP on the Crystal Growth, Polymorphism, and Morphology of CaCO3