Uniaxial Tensile Deformation And Fracture Process of Structures Forming By Unsaturated Intercalation of Amine Molecule Into C–S–H Gel

The application of cement based materials in engineering requires the understanding of their characteristics and subsequent deformation and fracture process of C-S-H gel in service. In this work, three types of amine molecules including TEPA, PAM and TEA were intercalated unsaturatedly into C–S–H gel successfully. Systematical analysis was performed on the structures and properties on both C–S–H gel and corresponding amine molecules / C–S–H gel. It was found that unsaturated intercalation of amine molecules into C–S–H gel plays a key role in the geometry and therein density of nanocomposites. Subsequently, radial distribution function (RDF), time correlated function (TCF) and mean square displacement (MSD) were applied to characterize the structure and dynamic information of the as-generated nanocomposites, demonstrating the occurance of interaction between amine molecules with Ca–Si layer and acceleration of water diffusion by unsaturated intercalation of amine molecules into the interlayer region in C–S–H gel. Finally, deformation and fracture process of C–S–H gel and amine molecules / C–S–H gel under uniaxial tensile loads were displayed by molecular dynamics simulation. It was indicated that Young’s modulus of nanocomposites demonstrates a strain softening nature, indicating a visco-elastic behavior. The breakage of Ca–O bonds and hydrogen bonds dominates the fracture of C–S–H gel. Weak interaction for TEPA / C–S–H gel or TEA / C–S–H gel leads to a decreased tensile strength. Local stress concentration in other interlayer region governs the deformation and fracture process in spite of the formation of strong interaction between double bonded polar oxygen atoms in PAM molecules and Ca atoms in C–S–H gel.

Crystal structure of 4-(2-hydroxy-3-methoxybenzylamino)benzoic acid dimethylformamide monosolvate monohydrate

The title compound, C15H15NO4·C3H7NO·H2O, a secondary amine molecule, is accompanied by one equivalent of water and one equivalent of dimethylformamide (DMF) as solvents. The molecule is non-planar, with a Caryl—CH2—NH—Caryl torsion angle of −66.3 (3)°. In the crystal, O—H...O and N—H...O hydrogen-bonding interactions between the amine molecules and the two types of solvent molecule result in the formation of a layered structure extending parallel to (010).

Crystal structure of 4-[(2-hydroxy-3-methoxybenzyl)amino]benzoic acid hemihydrate

In the crystal of the title vanilline derivative, 2C15H15NO4·H2O, the secondary amine molecule is accompanied by half equivalent of water. The molecule is non-planar, with torsion angle Caryl—CH2—NH—Caryl of −83.9 (2)°. In the crystal, the system of O—H...O hydrogen bonds, including bridging water molecules residing on crystallographic twofold axes, results in a two-dimensional layered structure. Within the layers, there are also weak N—H...π interactions involving the vanilline benzene ring.

Properties and Characteristic of Amine-Polymer Blend Membrane

Polymer blend technology has earned a significant position in the field of polymer science. Current membrane technology can easily and simply remove and separates carbon dioxide as pressure, temperature, costs, and energy requirements are low. There is also no corrosion problem from the straightforward process of removing CO2 from natural gas, especially in remote or offshore locations that are easily scaled up. However, glassy polymeric membranes suffer from a lack of permeability causing performance degradation and higher selectivity. Nevertheless, amine solutions are capable of purifying naturally acidic gas. Within this framework, the blending of the polysulfone (PSU) glassy polymer with amines such as diethanolamine (DEA), methyl diethanolamine (MDEA), and monoethanolamine (MEA) in a dimethylacetamide solvent, resulted in the development of flat sheet membranes with the desired properties. The findings showed good miscibility between PSU and amines blends, all the original functional groups were shown by FTIR. The synthesized amine polymer blend membrane were found to have homogenous surfaces and a packed bed sphere structure (PBSS) as shown by FESEM images. Furthermore the addition of different amine solution, have increased the size of PBSS due to incorporation of amine molecule into the sphere.

Defect-mediated electron–hole separation in an inorganic–organic CdSxSe1−x–DETA solid solution under amine molecule-assisted fabrication and microwave-assisted method for promoting photocatalytic H2 evolution

Inorganic–organic CdSxSe1−x–DETA solid solution shows high visible light photocatalytic H2 evolution activity.

Separation of carbon dioxide and nitrogen gases using novel composite membranes

Global warming is the major environmental issue caused by greenhouse gases, especially CO2. This demands urgent action to reduce or offset CO2 emission from power plants, which could be done using facilitated transport membranes (FTMs). In this context, CO2 selective carriers were prepared by blending polyvinyl alcohol (PVA) with three amines: ethylenediamine (EDA), diethylenetriamine (DETA), and triethylenetetramine (TETA). Then, the composite membranes were prepared using PVA–amine blend as the separation layer and ceramic candle filters as the support layer. The fabricated membrane was characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Furthermore, the effect of amine species, effect of TETA concentration, cross-linking agent content, pressure difference, and the thickness of the membrane on the permeance and selectivity of CO2 over N2 were investigated. The permeance and selectivity of CO2 through the membranes were in the following order: TETA > DETA > EDA. This order is related to the number of nitrogen atoms per amine molecule, which can be correlated to loading capacity and, consequently, to amine reactivity with CO2. Under optimized conditions, for a pure gas experiment, the maximum permeance of 6.9 GPU for CO2 gas and selectivity of 50 over N2 was obtained, whereas in the CO2/N2 gas mixture, the maximum permeance of 8.6 GPU and selectivity of 98 was obtained. The membrane was found to be stable for 264 h.