A version of thermoporometry dedicated to analyzing the pore network of expanding clays is proposed here. The blurred, wide Differential Scanning Calorimetry (DSC) peak obtained upon the melting of a frozen clay sample is processed by means of a deconvolution analysis based on searching for such a temperature distribution of “pulse-like heat events” which, convolved with the apparatus function, gives a minimal deviation from the observed heat flux function, i.e. the calorimetric signal. As a result, a sharp thermogram was obtained which can be transformed easily into the pore-size distribution curve. Results obtained for samples of two Clay Minerals Society Source Clays (montmorillonites SWy-2 from Wyoming and STx-1b from Texas) at different water contents indicate a greater resolution and sensitivity than that achieved by classical thermoporometry using the unprocessed DSC signal. Phenomena corresponding to the evolution of the pore network as a function of the water content have been detected in samples with large water contents subjected to free drying prior to the experiments.

The serpentine subgroup mineral berthierine was synthesized as a metastable precursor of the chlorite group mineral chamosite in cold seal pressure vessels at 575°C, 0.5 GPa and fO2-conditions of the NNO buffer from a glass of almandine bulk composition. The run products were investigated with X-ray powder diffraction (XRD), Mossbauer spectroscopy and electron microprobe analysis. One run product was also investigated by high-resolution transmission electron microscopy (HRTEM) and its heat capacity measured by heat pulse calorimetry and by differential scanning calorimetry in the temperature range 5–323 K. The XRD and HRTEM investigations clearly showed that the periodicity along the c axis of this sample is 7 Å demonstrating that the serpentine subgroup mineral berthierine of composition (Fe2+1.83Fe3+0.33Al0 67)[Si1.33Al0.67O5](OH)4 has formed in the synthesis experiments.

Integration of our heat capacity data, corrected to the composition (Fe2.5Al0.5)[Si1.5Al0.5O5](OH)4 for end-member berthierine, yields a standard entropy of 284.1±0.3 J mol−1 K−1. The Cp polynomial Cp = 610.72 − 5140.0 × T−0.5 − 5.8848 × 106T−2 + 9.5444 × 108T–3 is recommended for thermodynamic calculations above 298 K involving berthierine.

A commercially available combined X-ray diffraction – differential scanning calorimetry (XRD-DSC) stage was adapted for studies of gas loading in microporous materials, including metal organic frameworks (MOFs). Insertion of a custom-built humid atmosphere swing chamber (HASC) between a humidity generator and the XRD-DSC stage facilitates both humid atmosphere and vacuum swing gas loading. The HASC is necessary to buffer between the humidity generator and the XRD-DSC stage, allowing the gas mixture to homogenize prior to sample exposure, so that both humid atmosphere and vacuum swings could be performed. The changes in XRD can be used to follow structural changes, including collapse, which is indicative of a lack of microporosity upon activation, and the flexibity of frameworks upon gas sorption–desorption cycles. Measurements of the area under the DSC curve allows for calculation of the isosteric heat of adsorption (Qst; kJ molGAS−1). Vacuum-atmosphere swing experiments performed at different pressure steps allow for the reconstruction of the enthalpy of gas adsorption before and after a phase transition. These modes of operation are illustrated in three case studies from a program of exploratory MOF synthesis used to discover novel materials for selective gas sorption from humid gas streams: (1) gas binding in Stony Brook metal organic framework-1, (2) zeolitic imidazolate framework-7 response to variable pressure vacuum-atmosphere swing, and (3) high throughput evaluation of the selectivity of novel MOFs synthesized from customized linkers.

The aim of rational drug design is to develop small molecules using a quantitative approach to optimize affinity. This should enhance the development of chemical compounds that would specifically, selectively, reversibly, and with high affinity interact with a target protein. It is not yet possible to develop such compounds using computational (i.e., in silico) approach and instead the lead molecules are discovered in high-throughput screening searches of large compound libraries. The main reason why in silico methods are not capable to deliver is our poor understanding of the compound structure–thermodynamics and structure–kinetics correlations. There is a need for databases of intrinsic binding parameters (e.g., the change upon binding in standard Gibbs energy (ΔGint), enthalpy (ΔHint), entropy (ΔSint), volume (ΔVintr), heat capacity (ΔCp,int), association rate (ka,int), and dissociation rate (kd,int)) between a series of closely related proteins and a chemically diverse, but pharmacophoric group-guided library of compounds together with the co-crystal structures that could help explain the structure–energetics correlations and rationally design novel compounds. Assembly of these data will facilitate attempts to provide correlations and train data for modeling of compound binding. Here, we report large datasets of the intrinsic thermodynamic and kinetic data including over 400 primary sulfonamide compound binding to a family of 12 catalytically active human carbonic anhydrases (CA). Thermodynamic parameters have been determined by the fluorescent thermal shift assay, isothermal titration calorimetry, and by the stopped-flow assay of the inhibition of enzymatic activity. Kinetic measurements were performed using surface plasmon resonance. Intrinsic thermodynamic and kinetic parameters of binding were determined by dissecting the binding-linked protonation reactions of the protein and sulfonamide. The compound structure–thermodynamics and kinetics correlations reported here helped to discover compounds that exhibited picomolar affinities, hour-long residence times, and million-fold selectivities over non-target CA isoforms. Drug-lead compounds are suggested for anticancer target CA IX and CA XII, antiglaucoma CA IV, antiobesity CA VA and CA VB, and other isoforms. Together with 85 X-ray crystallographic structures of 60 compounds bound to six CA isoforms, the database should be of help to continue developing the principles of rational target-based drug design.

The dehydration of hexadecyltrimethylammonium (HDTMA)-exchanged smectites has been studied using X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The basal spacing of hydrated HDTMA-smectites changed with temperature. The 2.5 HDTMA-smectite (i.e. smectite treated with HDTMA equivalent to 2.5 times the CEC) showed a continuous increase in its basal spacing during dehydration up to 200ºC, while the 1.2 HDTMA-smectite showed a significant decrease in basal spacing. It is assumed that the less ordered alkyl chains in the wet state in the interlayer region may be rearranged to ordered chains (e.g. all-trans conformation) during sequential dehydration. This results in a decrease in interlayer spacing in the phase with low organic packing density and a flat-lying array (i.e. 1.2 HDTMA-smectite), and a gradual increase in the basal spacing when the chains have a vertical configuration (2.5 HDTMA-smectite).

The dolomite-ferroan-dolomite-ankerite series of carbonate minerals has been investigated in flowing carbon dioxide using high-temperature DSC. Decomposition products were analysed by X-ray diffraction. The minerals studied included dolomite containing no iron, and members substituted by iron in the molar ratio range of 0.082 to 0.49. Complete resolution of the three main endothermic features was observed and enthalpy values ΔH, determined from each. The individual and total enthalpy values showed a linear dependence upon the Fe and Mg content of the members across the series. A decrease in the enthalpy of decomposition occurs with increasing Fe content. The effect of Fe substitution was readily observed and the estimated limit of detection is less than 1% FeO. Accuracy of the measurements was limited by the purity of the minerals themselves.

Phase relations along the join bornite (Cu5FeS4)-digenite (Cu8.52Fe0.12S4.88) have been redefined using a combination of in situ high-resolution neutron diffraction and differential scanning calorimetry (DSC). Time-of-flight neutron diffraction patterns were collected on a synthetic sample of bn90 at 16 temperatures between 35 and 350°C. This data is compared with data from a natural end-member bornite sample obtained in an earlier study under identical conditions. Phase relations along the bornite-digenite join are inferred from the temperature evolution of the lattice parameters and the intensity of subcell and supercell reflections of coexisting phases.

The DSC scans over the temperature range 50–300°C were performed on a natural digenite sample and samples synthesized at 5 mol.% intervals along the join Cu5FeS4-Cu9S5. The thermal anomalies are correlated with structural phase transitions in componen phases and the solvus temperature for each bulk composition. A phase diagram topology is defined, which was consistent with both diffraction and calorimetric data, but in marked contrast to previous diagrams, shows a consolute point at X = Cu5FeS4 and T = 265°C. This temperature corresponds to that of the tricritical intermediate-high transition in bornite. Isothermal annealing experiments carried out on synthetic starting materials for up to 7 months showed coarsening behaviour consistent with the revised phase diagram topology.

In this work, differential scanning calorimetry (DSC) was used to characterize and analyze the precipitation/dissolution kinetics of second phase particles during the cooling/reheating process in a vanadium microalloyed steel. The results indicated that three obvious exothermic peaks were detected on the cooling DSC curve. Furthermore, three corresponding endothermic peaks were also detected on the heating DSC curve. Combined with thermodynamic calculation and transmission electron microscopy analysis, these three exothermic peaks along cooling DSC curve were defined as the precipitation reaction of V(CN), the reaction of austenite transformation into ferrite and the precipitation reaction of VC, respectively. Meanwhile, three corresponding reverse reactions for cooling were also defined along the reheating DSC curve. The linear regression result revealed that the precipitation activation energies for V(CN) and VC were identified as 311.2 kJ/mol and 167.6 kJ/mol, respectively. The dissolution activation energies for VC and V(CN) were identified as 255.4 kJ/mol and 592.6 kJ/mol, respectively.

Hybrid material based on halloysite nanotubes (HNTs) and sodium perfluorooctanoate (NaPF8) was used as a consolidant for paper treatment. The consolidation efficiency was determined by thermogravimetry as well as by paper grammage determination. Morphological analysis of the treated paper was performed by means of scanning electron microscopy while the effect of modified HNTs on the thermal behaviour of the cellulose fibres was investigated by differential scanning calorimetry which determined the combustion enthalpy of the paper.Water contact angle measurements were performed to study the paper wettability. The physico-chemical properties investigated (mesoscopic structure, thermal stability and wettability) of the treated paper were correlated successfully with the consolidation loading and, consequently, to the affinity between the fluorinated modified HNTs and the fibrous cellulose structure. This study proposes a new green protocol for paper consolidation based on natural tubular nanoparticles with a flame retardant effect.

The nature of glass transitions in chalcogenides and modified oxides depends on the network mean coordination number $\langle r\rangle$. These display systematic trends when spanning across the three topological phases: flexible, intermediate, and stressed-rigid. Trends in the glass-transition temperature Tg($\langle r\rangle$) show a monotonic increase with $\langle r\rangle$, but the nonreversing enthalpy of relaxation at Tg, ΔHnr($\langle r\rangle$), shows a deep- and square-well-like minimum with the walls representing the rigidity and stress transitions with increasing $\langle r\rangle$, respectively. In the well, the ΔHnr($\langle r\rangle$) term remains minuscule (∼0) corresponding to the isostatically rigid intermediate phase (IP). The melt fragility index (m) shows rather low values, m($\langle r\rangle$) < 20 for IP compositions, but increases outside the IP. Glass compositions in the IP show absence of network stress, form compacted networks, possess thermally reversing glass transitions, and display high glass-forming tendency—functionalities that have attracted widespread interest in understanding the physics of glasses and applications of the new IP formed.

The effectiveness of different routes of equal channel angular pressing (A, Bc, and C) is studied for commercially pure copper. The stored energy and the activation energy of recrystallization for the deformed samples were quantified using differential scanning calorimetry and X-ray diffraction line profile analysis. Results of the study revealed that the dislocation density and the stored energy are higher in the case of route Bc deformed sample. The activation energy for recrystallization is lower for route Bc.

The stability of camel α-lactalbumin (α-la) against heat denaturation was measured, using circular dichroism (CD) and fluorescence spectroscopy, as well as differential scanning calorimetry (DSC). The experiments were performed in the presence of saturating concentrations of calcium as well as in the presence of EDTA, yielding to the apo form of α-la. The change in heat capacity (ΔCp) suggests a greater contribution of hydrophobic interactions to the stability of holo camel α-la than in its bovine counterpart. Overall the results obtained in this study suggest a greater stability of camel α-la than the bovine protein in both holo and apo states. Also CD experiments showed similar secondary structure for camel and bovine α-la and secondary structure of camel α-la was better preserved than that of bovine α-la during heat denaturation. The differences in thermal stability between the proteins from two species can be primarily ascribed to the difference in the quantity of hydrophobic interactions involved in their folding.

The premise of this paper is that the chemical potential of water strongly influences aging reactions in seeds, and that there will be an optimal chemical potential of water for seed longevity. If this is true, the optimum moisture content for storage and the optimal drying protocols should vary with the storage temperature, but should be predictable from water sorption isotherms. Isotherms for pea, soybean and peanut are given for temperatures between 65° and −150°C. Relative humidity/moisture content relationships were determined directly for temperatures between 5° and 50°C using saturated salt solutions. At extreme temperatures, isotherms were calculated from heat capacity measurements using differential scanning calorimetry or extrapolations of van't Hoff analyses. The family of isotherms was used to predict optimum moisture contents at storage temperatures between 65°C and −150°C. The optimal moisture contents for these three species are consistently shown to increase as the storage temperature is lowered.

Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to monitor changes in the secondary structure and thermal stability of β-lactoglobulin A and B in the presence of sodium dodecyl sulphate (SDS), N-ethylmaleimide (NEM), urea and cysteine. An increase in the thermal stabilities of both proteins was noted in the presence of 10 mM-SDS. In the presence of 50 mM-SDS, there was extensive denaturation of both variants. In general, the β-strand/β-sheet regions in the secondary structure of both variants were very susceptible to denaturation by SDS and cysteine, suggesting that these regions may be held by hydrophobic and disulphide bonds. At ambient temperature and physiological pH, a notable difference was observed in the 1636 and 1627 cm−1 regions of the FTIR spectra of the two β-lg variants. The results suggest possible differences in the nature of the β-sheet/β-strand distribution/content of the two proteins. Urea and NEM at a concentration of 50 mM, had little effect on the secondary structure and denaturation of both variants. New findings are presented which further indicate that although the β-lg B variant showed greater thermal stability than the A variant in all the cases studied, its denaturation temperature and secondary structure were affected to a greater extent by the protein perturbants than β-lg A.

The room-temperature liquid salt, ethylammonium nitrate (EAN), has been used to enhance the recovery of denatured-reduced hen egg white lysozyme (HEWL). Our results show that EAN has the ability to prevent aggregation of the denatured protein. The use of EAN as a refolding additive is advantageous because the renaturation is a one-step process. When HEWL was denatured reduced using routine procedures and renatured using EAN as an additive, HEWL was found to regain 75% of its activity. When HEWL was denatured and reduced in neat EAN, dilution resulted in over 90% recovery of active protein. An important aspect of this process is that renaturation of HEWL occurs at concentrations of 1.6 mg/mL, whereas other renaturation processes occur at significantly lower protein concentrations. Additionally, the refolded-active protein can be separated from the molten salt by simple desalting methods. Although the use of a low-temperature molten salt in protein renaturation is unconventional, the power of this approach lies in its simplicity and utility.

The amino terminal domain of enzyme I (residues 1–258 + Arg; EIN) and full length enzyme I (575 residues; EI) harboring active-site mutations (H189E, expected to have properties of phosphorylated forms, and H189A) have been produced by protein bioengineering. Differential scanning calorimetry (DSC) and temperature-induced changes in ellipticity at 222 nm for monomeric wild-type and mutant EIN proteins indicate two-state unfolding. For EIN proteins in 10 mM K-phosphate (and 100 mM KCl) at pH 7.5, ΔH ≅ 140 ± 10 (160) kcal mol−1 and ΔCp ≅ 2.7 (3.3) kcal K−1 mol−1. Transition temperatures (Tm) are 57 (59), 55 (58), and 53 (56) °C for wild-type, H189A, and H189E forms of EIN, respectively. The order of conformational stability for dephospho-His189, phospho-His189, and H189 substitutions of EIN at pH 7.5 is: His > Ala > Glu > His-PO32− due to differences in conformational entropy. Although H189E mutants have decreased Tm values for overall unfolding the amino terminal domain, a small segment of structure (3 to 12%) is stabilized (Tm ∼ 66–68 °C). This possibly arises from an ion pair interaction between the γ-carboxyl of Glu189 and the ε-amino group of Lys69 in the docking region for the histidine-containing phosphocarrier protein HPr. However, the binding of HPr to wild-type and active-site mutants of EIN and EI is temperature-independent (entropically controlled) with about the same affinity constant at pH 7.5: K′A = 3 ± 1 × 105 M−1 for EIN and ∼1.2 × 105 M−1 for EI.

The change in heat capacity ΔCp for the folding of ribonuclease A was determined using differential scanning calorimetry and thermal denaturation curves. The methods gave equivalent results, ΔCp = 1.15 ± 0.08 kcal mol−1 K−1. Estimates of the conformational stability of ribonuclease A based on these results from thermal unfolding are in good agreement with estimates from urea unfolding analyzed using the linear extrapolation method.

The effect of methylurea, N,N′-dimethylurea, ethylurea, and butylurea as well as guanidine hydrochloride (GuHCl), urea and pH on the thermal stability, structural properties, and preferential solvation changes accompanying the thermal unfolding of ribonuclease A (RNase A) has been investigated by differential scanning calorimetry (DSC), UV, and circular dichroism (CD) spectroscopy. The results show that the thermal stability of RNase A decreases with increasing concentration of denaturants and the size of the hydrophobic group substituted on the urea molecule. From CD measurements in the near- and far-UV range, it has been observed that the tertiary structure of RNase A melts at about 3 °C lower temperature than its secondary structure, which means that the hierarchy in structural building blocks exists for RNase A even at conditions at which according to DSC and UV measurements the RNase A unfolding can be interpreted in terms of a two-state approximation. The far-UV CD spectra also show that the final denatured states of RNase A at high temperatures in the presence of different denaturants including 4.5 M GuHCl are similar to each other but different from the one obtained in 4.5 M GuHCl at 25 °C. The concentration dependence of the preferential solvation change ΔΓ23, expressed as the number of cosolvent molecules entering or leaving the solvation shell of the protein upon denaturation and calculated from DSC data, shows the same relative denaturation efficiency of alkylureas as other methods.