Feng Sha

Morphology Control in the Synthesis of CaCO3 Microspheres with a Novel CO2-Storage Material

A green and template-free method was applied to control the morphology of CaCO3 microspheres with a layered nanostructure surface and pure crystalline phase of vaterite via the hydrothermal reaction between Ca(OH)2 saturated limpid solution and a novel CO2-storage material (CO2SM). Morphologies of the as-prepared CaCO3 crystals could be tuned with CO2SM concentration, reaction temperature, or crystallization time. After the precipitation of CaCO3 crystals, the filtered solution could not only be used to absorb CO2 but also to produce CaCO3 microspheres repeatedly with the addition of Ca(OH)2 solution. Furthermore, an aggregation and self-assembly mechanism for the formation CaCO3 microspheres had been proposed. As a result, this novel synthesis strategy of CaCO3 microspheres with CO2SM again emphasized that was possible to synthesize inorganic/organic hybrid materials with exquisite morphology and offered an alternative way for comprehensive utilization of CO2.

Control over crystallization of CaCO3 micro-particles by a novel CO2SM

Different morphologies of CaCO3 micro-particles through a hydrothermal reaction between Ca(OH)2 saturated limpid solution and a new CO2-storage material (CO2SM), which was obtained from an equimolar system 1,2-ethylenediamine (EDA) + 1,2-ethylene glycol (EG) uptaking CO2, were presented without any additives. Its worth noting that the morphologies of the CaCO3 precipitates could be controlled as uniform sheaf-like (pure calcite) at the lower CO2SM concentration (0.6 g L−1) and homogeneous spherical-like (pure vaterite) at the higher CO2SM concentration (40 g L−1) for 1 h at 100 °C, in which the released EDA and/or EG from CO2SM had unexpected functions as surfactants. After the precipitation of CaCO3 crystals in 40 g L−1 CO2SM solution, the filtered solution could not only be reused to absorb CO2, but also to prepare the same crystal phase CaCO3 micro-particles repeatedly with the addition of Ca(OH)2. As a result, this novel synthesis process of CaCO3 micro-particles with CO2SM offers an alternative way for the comprehensive utilization of CO2.

A novel CCU approach of CO2 by the system 1,2-ethylenediamine+1,2-ethylene glycol

As a new, effective CO2 fixation system, 1,2-ethylenediamine and 1,2-ethylene glycol (EDA+EG) can efficiently activate CO2 and directly convert it into a novel CO2-storage material (CO2SM) with 46.3% yield. The aqueous CO2SM solution can react with Ca(OH)2-saturated limpid solution to generate morphology-controllable CaCO3 microparticles with additional CO2 bubbling and Ca(OH)2. Additionally, the aqueous EDA+EG solution could be recycled multiple times without significant loss of CO2 capturing and releasing capabilities.

Excess properties and spectroscopic studies of binary system of 1-methoxy-2-propanol + dimethyl sulfoxide at T = (298.15–318.15) K

ABSTRACT Thermophysical property data for the binary system of 1-methoxy-2-propanol (PGME) + dimethyl sulfoxide (DMSO), a potential candidate for use as the scrubbing liquid for the absorption of SO2, are lacking in the literature. This paper presents experimental data at 0.1 MPa on the density and viscosity for this binary system measured over the whole composition range at T = (298.15, 303.15, 308.15, 313.15 and 318.15) K. The extended combined uncertainty Uc with a 0.95 level of confidence for the pycnometer method and Ubbelohde viscometer used in this study is 0.002 g·cm−3 and 0.028 cm2·s−1, respectively. The PGME + DMSO system shows negative values of the excess molar volume at all temperatures and compositions. Based on UV-Vis and FTIR, the intermolecular interaction of PGME with DMSO was confirmed as hydrogen bonding between the hydroxyl hydrogen atom in PGME and the oxygen atom in DMSO.

Excess properties and spectroscopic studies of binary system 1,4-butanediol + water at T = (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K

ABSTRACT Density and dynamic viscosity data were measured over the whole concentration range for the binary system 1,4-butanediol (1) + water (2) at T = (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K as a function of composition under atmospheric pressure. Based on density and dynamic viscosity data, excess molar density (ρE), dynamic viscosity deviation (Δν) and excess molar volume (VmE) were calculated. From the dynamic viscosity data, excess Gibbs energies (ΔG*E), Gibbs free energy of activation of viscous flow (ΔG*), enthalpy of activation for viscous flow (ΔH*) and entropy of activation for viscous flow (ΔS*) were also calculated. The ρE, VmE, Δν and ΔG*E values were correlated by a Redlich−Kister-type function to obtain the coefficients and to estimate the standard deviations between the experimental and calculated quantities. Based on FTIR and UV spectral results, the intermolecular interaction of 1,4-butanediol with H2O was discussed.

Density, viscosity and excess properties for the binary system 2-butoxy ethanol + water at T = (298.15–318.15) K and mixture’s spectroscopic studies

ABSTRACT This report presents the density and viscosity data of binary system 2-butoxy ethanol (BOE) + water (H2O) over the entire composition range at T = (298.15, 303.15, 308.15, 313.15 and 318.15) K. On the basis of density and viscosity values, the excess molar volumes (), viscosity deviations (∆ν) and excess Gibbs free energies of activation (ΔG*E) were calculated. The computed results were fitted with the Redlich–Kister equation to derive the coefficients and estimate the standard deviations between the experimental and calculated values. The values of were negative, whereas the values of ∆ν were positive over the entire composition range. On the basis of the kinematic viscosity data, enthalpies, entropies and Gibbs energies of activation for the viscous flow were also calculated. Moreover, the intermolecular interaction of BOE with H2O was discussed on the basis of UV-Vis and FTIR spectral data.

Controllable synthesis of two CaO crystal generations: precursors' synthesis and formation mechanisms

In this study, novel rod-like and block-like CaO crystals were prepared after calcinating three types of CaCO3 precursors containing dumbbell-like, wheat spike-like and microsphere-like morphologies at 1000 °C for 3 h. The CaCO3 precursors were synthesized via the hydrothermal reaction of a CO2 storage-material (CO2SM) with Ca(OH)2 without additional additives. In the preparation process, CO2SM was not only used as a raw material but it also played the role of a directing agent. Moreover, as the major influence factors, CO2SM dosage, reaction temperature, reaction time and Ca2+ concentration were systemically investigated. Subsequently, the possible formation mechanism of the CaCO3 precursors was proposed. Finally, the as-obtained CaO crystals exhibit the adsorption amounts of 14.67, 16.32 and 7.50 mg g−1 for an 8% CO2/N2 mixture at 25 °C.

Liquid density, viscosity and spectroscopic studies of binary mixture of tetraethylene glycol + 1,2-ethanediamine for CO2 capture

ABSTRACT Thermophysical properties for binary mixture of tetraethylene glycol (T4EG) (1) + 1,2-ethanediamine (EDA) (2), a potential scrubbing solution for the absorption of CO2, are very important as well as lacking in the literatures. This work reports densities and viscosities over the entire concentration range for the binary mixture at T = (293.15-318.15) K under atmospheric pressure. According to the experimental density and viscosity values, the mixtures’ excess molar volume (VmE), absolute viscosity deviation (∆η), excess free energies of activation (∆G*E), apparent molar volumes, partial molar volumes and isobaric thermal expansion coefficient were calculated, respectively. Meanwhile, the VmE, ∆η and ∆G*E values were fitted by a Redlich–Kister equation to obtain coefficients. To further study, the Fourier transform infrared, UV-Vis and fluorescence spectra of T4EG + EDA mixtures with various concentrations were measured, and the intermolecular interaction of T4EG with EDA was also discussed as the formation of –OCH2CH2O–H···N(H2)CH2CH2(H2)N···.

Physicochemical properties and spectral studies of the 1,3-butanediol + dimethyl sulfoxide binary system at T = (293.15–318.15) K

ABSTRACT This work reports experimental dynamic viscosity (η) and density (ρ) for 1,3-butanediol (BTD) (1) and dimethyl sulfoxide (DMSO) (2) binary systems at T = (273.15–318.15) K and p = 0.1 MPa. From the experimental ρ and η data, the excess molar volumes () values, viscosity deviation (∆η) values, partial molar volumes ( and ) values, apparent molar volume (Vφ,1 and Vφ,2) values, excess free energies of activation () values and isobaric thermal expansion coefficient (αp) values were, respectively, obtained. After that, a Redlich–Kister equation was used to fit , ∆η and values. The mixtures exhibited positive with a maximum at x1 = 0.55, which became more pronounced after temperature increased. The obtained standard deviations (σ) values were compared with literature data and conclusion about application modus was drawn. From FTIR, UV–vis, FTIR and NMR spectral information, intermolecular interaction between BTD and DMSO was systemically explored.

Controllable synthesis of nanostructured BaSO4 and BaSO3 crystals on the basis of DMSO oxidation chemistry

A simple and novel SO2 release method for the synthesis of controllable nanostructured BaSO4 and BaSO3 crystals was developed based on the oxidation of HSO3− to SO42− by dimethyl sulfoxide (DMSO) in a binary system of triethylene glycol (TEG) + DMSO. The binary system was successfully re-used for SO2 absorption and production of BaSO3 crystals at least three times. Aggregation and self-assembly mechanisms for the preparation of BaSO4 and BaSO3 crystals were proposed. This controllable synthesis strategy for BaSO4 and BaSO3 crystals has offered an alternative way for the comprehensive utilization of SO2, and provided a scientific foundation for the development of DMSO oxidation chemistry.