Thermodynamic Analysis on Interaction between Molten Ti Alloys and Oxide Molding Materials

A thermodynamic model has been built up for the interactions between molten Ti alloys and oxide molding materials in the way of decomposition and solution of molding materials, then the influences on the reaction free energy changes have been calculated and discussed.

Microwave Synthesis of CdTe/TGA Quantum Dots and Their Thermodynamic Interaction with Bovine Serum Albumin

The thioglycollic acid（TGA） as a capping agent, CdTe/TGA quantum dots（QDs） with excellent properties were synthesized under microwave irradiation. The TGA/Cd/Te molar ratios, reaction time, temperature and p H are the crucial factors for properties of QDs. The QDs were characterized by UVvis absorption and fluorescence spectra, transmission electron microscopy and Fourier transform infrared spectroscopy. The experimental results show that when the p H value is 11.5 and molar ratio of TGA：Cd：Te is 1.2：1：0.4 at 100 ℃ heating for 15 min, the resulted QDs exhibit a high fluorescence quantum yield of 78%. The fluorescence full width at half maximum（FHMW） of QDs is around 23 nm. The products are spherical with average size of 3-5 nm. There is a strong coordination effect between TGA and Cd2＋. Moreover, the results of interaction between as-made QDs and bovine serum albumin（BSA） suggest that the QDs-BSA binding reaction is a static quenching. The negative values of free energy（△G〈0） suggest that the binding process is spontaneous, △H〈0 and △S〈0 show that hydrogen bonds and van der Waals interactions play a major role in the binding reaction between QDs and BSA.

Complexation of As(Ⅲ)by phosphonate ligands in aqueous fluids:Thermodynamic behavior,chemical binding forms and sequestering abilities

In recent years,the contamination of water by arsenic reached alarming levels in many countries of the world,attracting the interest of many researchers engaged in testing methodologies able to remove this harmful pollutant.An important aspect that must be taken into consideration is the possibility to find arsenic in different chemical forms which could require different approaches for its removal.At this aim,a speciation analysis appears to be crucial for better understanding the behavior of arsenic species in aqueous solutions,especially in presence of compounds with marked chelating properties.Phosphonates can be identified as good sequestering agents and,at this purpose,this manuscript intends to investigate the interaction of As(Ⅲ)with three phosphonic acids derived from nitrilotriacetic acid(NTA)by replacements of one(N-(Phosphonomethyl)iminodiacetic acid,NTAP),two(N,N-Bis-(phosphonomethyl)glycine,NTA2P)and three(Nitrilotri(methylphosphonic acid),NTA3P)carboxylic groups with the same number of phosphonate groups.An in-depth potentiometric and calorimetric investigation allowed to determine speciation models featured by simple ML,MLH i and ML(OH)species.A complete thermodynamic characterization of the systems is reported together with the definition of coordination mode by mass spectrometry measurements.On the light of the speciation models,the possibility of using these ligands in arsenic removal techniques was assessed by determining the pL 0.5(the concentration of ligand able to remove the 50%of metal ion present in trace).All ligands show a good sequestering ability,in particular under the conditions of fresh water,following the trend NTA3P>NTA2P>NTAP.