Papers by Keyword: Glycine

Abstract: Hydrophilic amino acids as a new type hydrate inhibitor is a hot topic for scholars. In this paper, the influence of glycine and L-arginine, and their complexation with polyvinylpyrrolidone (PVP) on hydrate formation were clarified by tetrahydrofuran (THF) hydrate formation simulation experiments, and the intrinsic influence mechanism was revealed by many experimental methods. The results show that glycine has a strong inhibitory effect on water molecules because of its strong disturbance to water molecules, and the inhibitory effect is the best when the addition of glycine is 1.0 wt%. Due to the disturbance and binding of hydrophilic amino acids to water molecules, the effect of PVP on the semi-cage structure of water molecules as well as the adsorption and encapsulation of hydrate crystal particles, the combination of glycine and L-arginine and PVP has synergistic inhibitory effect on the formation of THF hydrate. When the total amount of hydrate inhibitor is 1.0 wt%, the synergistic inhibition ability of glycine and PVP is stronger. The results obtained in this paper provide an experimental and theoretical basis for the research and development of new hydrate inhibitors.

Abstract: In this work, Fe₂O₃ nanooval is successfully synthesized with variation of glycine composition of 9, 12, and 15 mmol at hydrothermal temperature of 160 °C. The Fe₂O₃ nanooval is indexed by XRD as α-Fe₂O₃. SEM and TEM images show that the 12 mmol of glycine has the largest diameter with the perfect nanooval form. Nyquist plot shows that the 12 mmol of glycine sample has the best conductivity value of 8.26x10^-5 S/m. The CV of sample 12 mmol delivers the best intercalate/de-intercalate with ΔV of 0.82 V. The 12 mmol sample shows the largest specific discharge capacity of 631.62 mAh/g. It is attributed to high conductivity and high kinetics reaction of Li ion during charge-discharge process. Therefore, Fe₂O₃ nanooval is a promising candidate as anode for lithium-ion battery.

Abstract: CO₂ solubility in aqueous potassium carbonate promoted with amino acid (glycine) was measured at temperatures (303.15, 313.15, and 333.15) K over the partial pressure range from 200 to 1000 kPa. The solubility of CO₂ is reported as the loading capacity of the CO₂ in the solvent, defined as (moles of CO₂ per mole of solvent). It was found that the loading capacity of the CO₂ increases by increasing the partial pressure of the CO₂, whereas, it reduces with increase in temperature. CO₂ loading capacity in aqueous potassium carbonate (PC) promoted with glycine (GLY) was also compared with different solvents, which shows that the new solvent blend is considerably better than various solvents.

Abstract: The objective of this paper was to optimize the flocculation and biomass productivity of Botryococcus braunii by using an organic carbon source glycine. The effects of culture period and glycine dose with high, medium and low levels on both solid concentration achieved and biomass productivity were conducted. It was found that extracellular polymeric substances (EPS), which promotes flocculation, was produced not only by bacterial but also by microalgae. The productivity of EPS was affected by culture period, glycine dose and mixing time. The maximum EPS of 103.3 mg/L obtained with 11 day culture period and 0.1 g/L glycine, leading to the maximum solid concentration achieved of 51 g/L, the biomass recovery rate 72%.

Abstract: While bio(organic-inorganic) compatibility and absence of cytotoxicity are crucial to create a successful nanocarrier for applications in biosensing and drug delivery, the study of its stability before commercialization is quite important. In the present work, the stability of gold nanoparticles (AuNPs) functionalized with L-Cysteine (Cys) and Cysteine-Glycine (Cys-Gly) was studied. The AuNPs surface modification with Cys and CysGly was performed to improve their biocompatibility and, after that, the stability of capped AuNPs was investigated. The synthetized AuNPs using 10 mM of cysteine and 20 mM of Cys demonstrated stability after 1 month of storage, while all other concentration ratios resulted in the formation of chain-like conglomerates. For AuNP capped with CysGly all modifier concentrations led to stable samples within 1 month of storage.

Abstract: Au nanoparticles (NPs) functionalized with L-cysteine (Cys) and cysteine-glycine (Cys-Gly) were synthetized. The AuNPs were prepared using sodium citrate as reducing agent. The influence of the molar concentrations of Cys and Cys-Gly, as well as the sodium citrate is studied on particle size and particle size distribution. TEM measurements revealed the formation of AuNPs with diameter in the range 5-35 nm which corresponds to nontoxic sizes [we should add a reference here, perhaps number one]. The optimal particle size for biomedical application along with narrow particle size distribution was observed for samples prepared with molar ratio of CAu:Ccitrate = 1:10. The results of UV-Vis spectroscopy revealed the interaction of the AuNPs with Cys and Gly-Cys demonstrated by a visible change in the absorption intensities of the plasmon peak located at 520 nm after AuNP functionalization and a slight shifting of this gold nanoparticles plasmon peak. Thus, any dielectric shell on surface of particles with more refraction index (and, correspondingly, dielectric function) can produce the particles with the red shift. Such effect of the surface shell with red-shift in the range of few nanometers observed for the AuNPs functionalized with Cys and Cys-Gly (Fig. 4) can be interpreted as thin or discontinuous layer of aminoacid molecules according to the data of optical spectra simulation.

Abstract: Our goal is to develop methoxy poly (ethylene glycol) (m-PEG) decorated, glycine capped magnetic nanoparticles (MNPs) with proper physicochemical characteristics including particle size and magnetic property. MNP were synthesized by a biocompatible chemical co-precipitation of Mn²⁺ and Fe³⁺ in a sodium hydroxide solution. In order to covalently modify nanoparticles surface by previously prepared m-PEG aldehyde, glycine was used as linker. X-ray diffraction analysis showed successful formation of pure nanocrystalline single phase of Mn-Ferrite and FT-IR spectroscopy approved that m-PEG and glycine were covalently bound to nanoparticles surface. Particle size study showed significant change after modification. In addition, the Vibrating sample magnetometry was done for measuring the magnetic properties (Ms: 52 emu/g) and showing the superparamagnetism behavior.

Abstract: nano Al₂O₃ powders have been synthesized by a solution combustion method (SCS) using glycine as a fuel and ammonium nitrate as an extra oxidizer. The effectiveness and influence of oxidizer/fuel ratio and the water contetnt of the solution on the crystallite size and characteristics of alumina particles was investigated respectively. As-synthesized powders were γ-alumina due to calcination of samples at 900 ^̊C for 2 hours. Also, Results demonstrated that the alumina nanoparticles obtained from φ=1.8 had crystallite sizes around 65 nm which is less than other values of φ, due to evolution of larg amounts of gases which inhibits grain growth and less adiabatic temperature during the process. Also, it was concluded that the more the water content of the solution, the less the crystallinity and crystallite sizes of the products as a result of decreased adiacatic temperature.

Abstract: Nano-particles of (38 nm size) cobalt ferrite (CoFe2O4) were synthesized by sol-gel auto-combustion technique using high purity metal nitrates and glycine as a fuel. The characterization studies were conducted by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The analysis of X-ray diffraction pattern suggests that, the prepared CoFe2O4 spinel ferrite possess single phase cubic spinel structure. The most intense peak (311) of the XRD pattern was used to determine the crystallite size. lattice constant and X-ray density were calculated by using XRD data. The values of lattice constant and X-ray density are found to in the reported range but slightly higher as compared to bulk CoFe2O4 sample. The surface morphology of the CoFe2O4samples was examined through scanning electron microscopy (SEM) technique. The result of SEM analysis shows that grain size is of the order of 62 nm. The CoFe2O4 nano-particle exhibit ferromagnetic behavior having saturation magnetization (Ms) and coercivity (Hc) values in the range of 83 emu/gm and 1381 Oe respectively. The high values of saturation magnetization and coercivity gives the evidence of nanocrystalline nature of the prepared CoFe2O4 spinel ferrite.

Abstract: With the elution curves of glycine and taurine, the ion exchange isotherm parameters of glycine and taurine on D290 anion exchange resin are determined by the inverse method. In this work, with the multi-component competitive ion exchange isotherm and the equilibrium dispersion chromatographic model, the elution curves of glycine and taurine on D290 anionic fixed bed are fitted. The parameters of competitive isotherm are determined, K_tau is 2.55, K_gly is 1.65. The result s showed good agreement between the elute curves fitted by the model and the separation data which confirmed the validity of the model selected.Keywords-taurine; glycine;competitive isotherm;inverse method;