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The dissolution properties of 2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (Keto-RDX) in dimethyl sulfoxide (DMSO) were studied by using a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. The heat effects, molar enthalpies (Δ diss H), and differential enthalpies (Δ dif H) of dissolution were determined. Furthermore, the corresponding kinetic equations describing the dissolution processes at the four experimental temperatures are dα/dt = 10−2.43 (1 − α)0.63 (T = 298.15 K), dα/dt = 10−2.41 (1 − α)0.67 (T = 303.15 K), dα/dt = 10−2.40 (1 − α)0.75 (T = 308.15 K), and dα/dt = 10−2.38 (1 − α)0.76 (T = 313.15 K). The determined values of the activation energy E and pre-exponential factor A for the dissolution process are 5.99 kJ mol−1 and 10−1.38 s−1, respectively.

Knowledge of the effect of aluminosilicates in fly ash on slagging is very important for the prevention and control of slagging in coal-fired boilers. To understand hydrochloric acid dissolution of the aluminum element of fly ash aluminosilicates at a chemical coordination level and establish a reliable method to characterize fly ash aluminosilicates that easily cause slagging, we performed hot hydrochloric acid separation for fly ashes with different melting points obtained from four power plants in China and measured the acid-solubility of major elements in the fly ashes. The fly ashes and their acid separation residues were analyzed using X-ray diffraction and 27Al magic-angle spinning nuclear magnetic resonance (27Al MAS NMR). The results show that the 6-fold coordinated aluminum (denoted as Al(VI)) in the fly ashes does not easily dissolve in hot hydrochloric acid. One part of the 4-fold coordinated aluminum (denoted as Al(IV)) easily dissolves in hydrochloric acid. The acid-soluble Al(IV) in ash has...

The molar enthalpies of dissolution for 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) in dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K under atmospheric pressure. Empirical formulae for the calculation of the molar enthalpies of dissolution (Δdiss H), relative partial molar enthalpies (Δdiss H partial) and relative apparent molar enthalpies (Δdiss H apparent) were obtained from the experimental data of the dissolution processes of LLM-105 in DMSO or NMP. Furthermore, the corresponding kinetic equations describing the two dissolution processes were dα/dt = 10−2.37(1 − α)0.47 for the dissolution of LLM-105 in DMSO, and dα/dt = 10−2.38(1 − α)0.42 for the dissolution of LLM-105 in NMP.

The molar enthalpies of dissolution for potassium salt of bis(dinitromethyl)difurazanyl ether [K2(BDFE)] in N-methyl-2-pyrrolidone (NMP) and water were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K under atmospheric pressure. Empirical formulae for the calculation of the molar enthalpies of dissolution (Δdiss H), relative partial molar enthalpies (Δdiss H partial), and relative apparent molar enthalpies (Δdiss H apparent) were obtained from the experimental data of the dissolution processes of K2(BDFE) in NMP or water. Furthermore, the corresponding kinetic equations describing the two dissolution processes were dα/dt = 10−4.11(1 − α)1.12 for the dissolution of K2(BDFE) in NMP and dα/dt = 10−3.76(1 − α)0.88 for the dissolution of K2(BDFE) in water.

The corrosion behaviors of a basic type of RE-containing magnesium alloy Mg-15Y processed by different heat treatment methods were studied in 3.5% NaCl solution at room temperature. The amount of Mg24Y5 phase decreased with the extending of homogenization treatment. The time for achieving dissolving equilibrium of homogenization treatment at 525, 535, and 545 ° was 24, 20, and 8 h, respectively. The corrosion behavior of Mg-15Y alloy was studied using immersion, hydrogen evolution and electrochemical tests. The experimental results revealed that the heat treatment improved the corrosion resistance, and the corrosion resistance became better with increasing the heat treatment time. The corrosion mode of the alloy after heat treatment was microgalvanic corrosion consisting of the cathodic Mg24Y5 phase and anodic α-Mg matrix, and Mg-15Y exhibited favorable uniform corrosion mode in NaCl solution. The volume and increasing tendency of the homogenization treatment samples were both more than those of the as-cast sample.

The dissolution properties of 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowutrzitane (TEX) in N-methyl pyrrolidone (NMP) were studied with a RD496-2000 Calvet microcalorimeter at four different temperatures. The heat effects were measured for TEX in NMP. The molar enthalpies and the differential molar enthalpies for TEX in NMP were also obtained at the same time. The corresponding kinetic equations that describe the four dissolution processes are dα/dt = 10−2.64(1−α)1.31 (T = 298.15 K), dα/dt = 10−2.58(1−α)1.31 (T = 303.15 K), dα/dt = 10−2.54(1−α)1.51 (T = 308.15 K), dα/dt = 10−2.49(1−α)1.03 (T = 313.15 K), and respectively. The values of activation energy E a and pre-exponential factor A for TEX in the dissolution process are 16.84 kJ mol−1 and 100.32 s−1.

The enthalpies of dissolution for dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) in dimethyl sulfoxide were measured using a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. Differential enthalpies (Δdif H) and molar enthalpies (Δdiss H) of dissolution were determined. Furthermore, the corresponding kinetic equations describing the dissolution processes at the four experimental temperatures are dα/dt = 10−2.60(1 − α)1.01 (T = 298.15 K), dα/dt = 10−2.59(1 − α)0.93 (T = 303.15 K), dα/dt = 10−2.58(1 − α)1.36 (T = 308.15 K), dα/dt = 10−2.57(1 − α)1.21 (T = 313.15 K). The determined values of the activation energy E and pre-exponential factor A for the dissolution process are 3.24 kJ mol−1 and 10−2.03 s−1, respectively.

The enthalpies of dissolution of dihydrazidinium bis(tetrazolyl)amine (DHBTA) in water and N-methyl pyrrolidone (NMP) were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K under atmospheric pressure, respectively. Empirical formulae for the calculation of the enthalpy of dissolution (Δdiss H), relative partial molar enthalpy (Δdiss H partial) and relative apparent molar enthalpy (Δdiss H apparent) were obtained from the experimental data of the dissolution processes of DHBTA in water and NMP. Furthermore, the corresponding kinetic equations describing the two dissolution processes were dα/dt = 10−2.70(1 − α)0.82 for the dissolution of DHBTA in water, and dα/dt = 10−2.47(1 − α)0.66 for the dissolution of DHBTA in NMP, respectively.

The enthalpy of dissolution of NNHT in N,N-dimethyl formamide (DMF) was measured by means of a DC08 Calvet microcalorimeter at 298.15 K. Empirical formulae for the calculation of the enthalpy of dissolution (ΔdissH), relative partial molar enthalpy (ΔdissHpartial), and relative apparent molar enthalpy (ΔdissHapparent) were obtained from the experimental data of the enthalpies of dissolution of NNHT in DMF. The kinetic equation that describes the dissolution process of NNHT in DMF at 298.15 K is determined as \( \frac{{{{\rm d}}\alpha }}{{{{\rm d}}t}} = 2.86 \times 10^{ - 3} (1 - \alpha )^{0.94} \).

Metal-organic frameworks (MOFs) with light-harvesting building blocks provide an excellent platform to study energy transfer in networks with well-defined structures. Here, we report the synthesis, dissolution-recrystallization structural transformation (DRST) and the Forster resonance energy transfer (FRET) properties of a 2D microporous MOF {[Cd2(L1)3(Hdabco)2]·5DMAc·6H2O}n (Cd-MOF, 1). Complex 1 can be dissolved in water and three other products with different dimensions recrystallized from the aqueous solution under diverse reaction conditions were obtained. Due to the porosity and excellent blue luminescence properties of complex 1, we also studied the FRET process between 1 and guest dyes. Two distinct organic dye molecules viz., acridine orange (AO) and rhodamine B (RhB), are encapsulated in 1 which has honeycomb-type nanochannels, and their influence on fluorescence emission has also been studied. The microporous complex 1 in (AO + RhB)@1 serves as an energy funnel that harvests high energy excitation and channels it onto AO and then onto RhB. The steady-state fluorescence and fluorescence dynamics of emission reveal successfully the process of stepwise vectorial energy transfer. Therefore, MOFs could be a class of promising host materials to be further explored in the field of energy transfer between MOF-host and organic guests.

The thermochemical properties of 2,4-dinitroanisole (DNAN) in N-methy pyrrolidone (NMP) and dimethyl sulfoxide(DMSO) were studied using a RD496-2000 Calvet microcalorimeter at four different temperatures. The heat effects were measured for DNAN dissolved in NMP and DMSO and the relationships between the heat effects and the amounts of the substance were determined. The molar enthalpies and the differential molar enthalpies of dissolution processes were also obtained from the experimental data. The corresponding kinetic equations describing the two dissolution processes at different temperatures were discussed.

The dissolution properties of ammonium dinitramide (ADN) in N-methyl pyrrolidone (NMP) were studied with a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. The heat effects were determined for ADN in NMP. The molar enthalpies and the differential molar enthalpies for ADN in NMP were also obtained at the same time. The corresponding kinetic equations that describe the four dissolution processes are discussed.

Abatract. The enthalpies of dissolution for nitroguanidine (NQ) in dimethyl sulfoxide (DMSO) andN,N-dimethylformamide (DMF) were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K. Empirical formula for the calculation of the enthalpies of dissolution (ΔdissH) was obtained from the experimental data of the dissolution processes of NQ in DMSO and DMF. The corresponding kinetic equations describing the dissolution processes were dα/dt=10-1.49(1-α)0.94for the dissolution of NQ in DMSO and dα/dt=10-1.59(1-α)0.90for the dissolution of NQ in DMF.

In order to fabricate micron-scale and submicron-scale porous morphologies on titanium implants more facilely, a one-step anodization treatment was developed. Through anodic oxidation in 1 M CH 3 COONa electrolyte in the step-galvanostatic mode, a crystalline titania layer with multi-level porous morphology was prepared on titanium substrate. The multi-level porous morphology consisted of micron-sized craters (2–20 μm) overlaid with densely distributed submicron pores (50–500 nm). The formation process of the multi-level porous structure was investigated and the possible mechanism was discussed. It can be concluded that both the CH 3 COONa electrolyte and the step-galvanostatic mode contributed to its formation. In addition, the development of craters was ascribed to gradual field-assisted dissolution by CH 3 COO − anions and submicron pores were generated by spark discharges.

Synthetic nanoparticles are always terminated with coating molecules, which are often cytotoxic and not desired in biomedicine. Here we propose a novel reaction-dissolution approach to remove the cytotoxic coating molecules. A two-component solution is added to the nanoparticle solution; one component reacts with the coating molecules to form a salt whereas another is a solvent for dissolving and thus removing the salt. As a proof of concept, this work uses a NaOH-ethanol solution to remove the cytotoxic linoleic acid molecules coated on the hydroxyapatite nanorods (HAP-NRs). The removal of the coating molecules not only significantly improves the biocompatibility of HAP-NRs but also enables their oriented attachment into tightly-bound superstructures, which mimic the organized HAP crystals in bone and enamel and can promote the osteogenic differentiation of mesenchymal stem cells. Our reaction-dissolution approach can be extended to the surface "cleaning" of other nanomaterials.

The properties of dissolution in different solvents, the specific heat capacity and thermal decomposition process under the non-isothermal conditions for energetic triazole ionic salts 1,2,4-triazolium nitrate (1a), 1,2,3-triazolium nitrate (1b), 3,4,5-triamino-1,2,4-triazolium nitrate (2a), 3,4,5-triamino-1,2,4-triazolium dinitramide (2b) were precisely measured using a Calvet Microcalorimeter. The thermochemical equation, differential enthalpies of dissolution (Δdif H m Θ ), standard molar enthalpies of dissolution (Δdif H m Θ ), apparent activation energy (E), pre-exponential constant (A), kinetic equation, linear relationship of specific heat capacity with temperature over the temperature range from 283 to 353 K, standard molar heat capacity (C p,m Θ ) and enthalpy, entropy and Gibbs free energy at 283–353 K, taking 298.15 K as the benchmark for 1a, 1b, 2a and 2b were obtained with treating experimental data and theoretical calculation method. The kinetic and thermodynamic parameters of thermal decomposition reaction, critical temperature of thermal explosion (T b), self-accelerating decomposition temperature (T SADT) and adiabatic time-to-explosion (t) of 1a, 1b, 2a and 2b were calculated. Their heat-resistance abilities were evaluated. Information was obtained on the relation between molecular structures and properties of 1a, 1b, 2a and 2b.

The enthalpies of dissolution of 1,2,4-triazole nitrate in N-methyl pyrrolidone (NMP) were measured using a RD496−2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. Differential enthalpies (ΔdifH) and molar enthalpies (ΔdissH) were determined for 1,2,4-triazole nitrate in NMP. The corresponding kinetic equations that describe the four dissolution processes are discussed.

The dissolution properties of 3,4,5-triamino-1,2,4-triazole dinitramide in N-methyl pyrrolidone (NMP) was measured using a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. Differential enthalpies (Δ dif H) and molar enthalpies (Δ sol H) were determined for 3,4,5-triamino-1,2,4-triazole dinitramide in NMP. The corresponding kinetic equations that describe the four dissolution processes are dα dt = 1.78 × 10 -4 (1 - α) 1.01 (T = 298. 15 K ), dα /dt = 1 . 9 6x 10 -4 (1-α) 1.06 ( T = 303 . 15 K ), dα/ dt = 215 × 10 -4 (1-α) 0.96 (T=308.15 K), dα/ dt = 234 × 10 -4 (1-α) 1.06 (T = 313.15 K) for the dissolution of 3,4,5-triamino-1,2,4-triazole dinitramide in NMP, respectively. The values of activation energy E and pre-exponential factor A for the dissolution process are obtained as 14.13 kJ·mol -1 and 5.34 x 10 -2 s -1 .

The enthalpies of dissolution in ethyl acetate and acetone of hexanitrohexaazaisowurtzitane (CL-20) were measured by means of a RD496-2000 Calvet microcalorimeter at 298.15 K, respectively. Empirical formulae for the calculation of the enthalpy of dissolution (ΔdissH), relative partial molar enthalpy (ΔdissHpartial), relative apparent molar enthalpy (ΔdissHapparent), and the enthalpy of dilution (ΔdilH1,2) of each process were obtained from the experimental data of the enthalpy of dissolution of CL-20. The corresponding kinetic equations describing the two dissolution processes were \( {\frac{{{\text{d}}\alpha }}{{{\text{d}}t}}} = 1.60 \times 10^{ - 2} (1 - \alpha )^{0.84} \) for dissolution process of CL-20 in ethyl acetate, and \( {\frac{{{\text{d}}\alpha }}{{{\text{d}}t}}} = 2.15 \times 10^{ - 2} (1 - \alpha )^{0.89} \) for dissolution process of CL-20 in acetone.

The enthalpy of dissolution of 1,1-diamino-2,2-dinitroethylene (FOX-7) in DMSO was measured by means of a RD496-2000 Calvet microcalorimeter at 298.15 K. Empirical formulae for the calculation of the enthalpy of dissolution (ΔdissH), relative partial molar enthalpy (ΔdissHpartial) and relative apparent molar enthalpy (ΔdissHapparent) were obtained from the experimental data of the enthalpies of dissolution of FOX-7 in dimethyl sulfoxide (DMSO). The dilution/crystallization kinetic behavior of FOX-7 in DMSO/water system was investigated and the kinetic equation describing the dilution/crystallization process was presented.

The chalcopyrite anode dissolution behavior in the presence or absence of bacteria in 9 K media using bacteria modified powder microelectrode at 30 °C was studied. It is found that during the anode dissolution, many intermediate transient reactions occur accompanying with the production of chalcocite and covellite at potential between −0.075 V and −0.025 V (vs SCE). At low scanning potential between −0.1 and −0.250 V, the iron ion is released in ferrous form, but at the relative high potential up to 0.7 V, it is the ferric one. The presence of Thiobacillus ferrooxidans makes peak current increase and the initial peak potential negatively move, hinting the decomposed oxidation reaction easily occurred and especially the iron ion released and ferrous oxidation reaction enhanced. The characteristic at potential between −0.75 and −0.5 V demonstrates the Thiobacillus ferrooxidans also contributes to the element sulfur formed on the oxidation surface and removed during anode process. The added ferric in the cell could enhance the dissolution reaction, while the increased acid under pH=2 might slightly hamper the process. The anode dissolution kinetics studies show that the presence of bacteria could decease corrosion potential from 0.238 V to 0.184 V and increase the corrosion current density from 1.632 14×10−8 A/cm2 to 2.374 11×10−7A/cm2.