Zeitschrift für chemische Wissenschaften

In this study, spherical Silica particles with narrow size distribution were prepared by hydrolysis of Tetraethyl OrthoSilicate (TEOS) in Ethanol and the presence of ammonia based on the Stober method. The average particle diameter and monodispersity were controlled by varying the concentration of TEOS. Microscopic analysis showed that a smaller average particle diameter and good degree of monodispersity can be obtained by decreasing the concentration of TEOS.

In this study, we are going to report a simple procedure to prepare and assemble noble metal nanoparticle chains using in situ synthesis of dicarboxylic acid (tartaric acid). The objective of this study is to investigate the effect of tartaric acid on silver and gold Nanoparticles (NPs). To address this issue, the optical properties, the morphology of silver, gold nanoparticles and their assemblies were investigated by Ultraviolet–Visible (UV-Vis) spectroscopy and Transmission Electron Microscopy (TEM). In addition, Fourier-Transform Infrared (FTIR) was also used to assure the formation of metal nanoparticles assemblies by means of esterification reaction. Gold and silver NPs colloids showed the typical local surface Plasmon resonance of isolated NPs with a symmetric absorption curve. This symmetry did not hold after the addition of the cross link. Moreover, two Plasmon modes were observed for both NPs, the one with longer wavelengths is a characteristic of the assembled NPs due to the near field Plasmon coupling. Furthermore, we observed a great correlation between concentration crosslink, reaction time and Surface Plasmon Band Absorption (SPBA).

Reaction of Azido-m-hemipinic acid (IV) with N-hydroxy Succinimide (NHS) and Dicyclohexyl Carbodiimide (DCC) has been investigated. The product (IV) has been identified as a tri-NHS adduct of the elusive O-acylisourea intermediate in DCC catalyzed reactions of carboxylic acids and alcohols/amines. Based on these observations, a question is posed whether ‘azido-m-hemipinic acid’ is to be considered as an “introverted” acid.

Biocomposite materials consisting of Poly-L-Lactic-Co-Glycolic Acid (PLGA) and Hydroxyapatite (HA) were synthesized and mechanical properties have been observed by carrying out the fatigue test, for which accelerated tests have been conducted such that 20%, 30% and 40% of the yield strength have been applied in a repeated mode until a crack occurred on the load-applied points of test specimen. Based on the fatigue test results, the lifetime of test specimen (B10 life) was estimated. It was found that Weibull distribution (shape parameter=8.79) was the most proper one to describe the failure data obtained from the accelerated fatigue tests. B10 life at 5% of yield strength was estimated to be 335,764 cycles (Confidence Level=95%, lower limit) by applying an inverse power model.

The drinking water in University of Education Vehari (UEV) was analyzed to monitor its Chloride hardness. This project was performed in chemistry Lab of UEV. The chemical/analytical test used to analyze the water Chloride hardness was Argentometric Titration or Mohr Method of analysis. In this test, a water sample was tested properly in chemistry lab. From the results, the molarity of Chloride content was calculated. The molarity of resulted Chloride was 0.0133, showing the most hardness of water. It is declared that due to hardness of Chloride amounts in drinking water, the water of university is unfit for drinking. This concentration of Chloride ions in very small water sample is too much. In normal, we daily intake 6-8 glasses of water which means 800-1000 ml or 1 L daily. If we calculate this concentration for 1 L, it will be most dangerous especially for human health. Chloride hardness causes various typical issues, for example, evaporator scaling, washing, spots on sink, sturdiness of hair and skin. It is also said that hard water causes diverse therapeutic problems; for example, urolithiasis, cardiovascular confusion, kidney problems, anencephaly. It can cause most of stomach diseases in humans. So, authors recommended using this water after boiling, filtration or chlorination of water.

In order to circumvent the problem of silanols polymerization in food supplement or cosmetics, the stabilizing power of phenolic molecules such as vanillin and frambinone was evaluated using two different siliceous molecules: orthosilicic acid and monomethylsilanetriol. NMR analyses confirmed the absence of polymeric species in formulations, conferring it a good bioavailability. The Silicon-phenol complexes demonstrated interesting biological properties on skin, collagen and cellular ageing proving that this complex reveals all the power of Silicon.