Preparation and Spectroscopic Properties of Tris (2, 2′-bipyridine)ruthenium(Ⅱ)Loaded in Siliceous Mesoporous MCM-41

[Ru (bpy)_3]^(2+)/MCM-41 composite material obtained by loading tris(2, 2' - bipyridine)ruthenium(Ⅱ) ([Ru (bpy)_3]^(2+) ) in siliceous mesoporous MCM-41 was characterized by X-ray powder diffraction, UV-Vis absorption and emission spectroscopies. The absorption spectrum of [Ru(bpy)_3]^(2+) /MCM-41 is similar to that of [Ru (bpy)_3]^(2+) aqueous solution, whereas its emission spectrum exhibits hypsochromic shift compared to the solution spectrum. On the other hand, the peak position of the emission spectrum of [Ru(bpy)_3]^(2+)/MCM-41 shifts towards longer wavelength when the loading amount increases.

Hexavalent Chromium Removal and Reduction to Cr (III) by Polystyrene Tris(2-aminoethyl)amine

A commercially available chelating polymer, polystyrene tris(2-aminoethyl)amine, was used for the removal of chromium from aqueous solution. The influence of pH, contact time, adsorbent dosage and initial Cr (VI) concentration on adsorption was studied. The optimum pH for the removal of Cr (VI) was at pH 5, while optimum contact time and adsorbent dosage were 120 minutes and 10 g/L, respectively. Total chromium and Cr (VI) concentrations were analyzed by ICP-MS and UV-Visible. Adsorption isotherms using Langmuir and Freundlich isotherm models revealed that the data fitted Langmuir isotherm model better than Freundlich with a maximum adsorption capacity of 312.27 mg/g. FTIR spectroscopy, Scanning electron microscopy (SEM) and Energy Dispersive Spectrometry (EDS) analyses were performed on the adsorbent before and after binding Cr (VI). All analyses confirmed the complexation of Cr (VI) to the adsorbent. Desorption experiments using KCl solution indicated 89.3% release of chromium, rendering this method of high potential for adsorbent regeneration.

Removal of Lead Ions from Wastewater Using Functionalized Multiwalled Carbon Nanotubes with Tris(2-Aminoethyl)Amine

Recently, many attempts have been made to use carbon nanotubes in analytical chemistry, especially in adsorption of heavy metal ions from water. In this study, multiwalled carbon nanotubes (MWCNTs) were functionalized with tris(2-aminoethyl) amine. The functionalized nanoparticles were characterized using Fourier transform infrared (FTIR), thermal gravimetric analyzer (TGA), elemental analysis, and Raman spectroscopy. The results revealed that the functionalization reaction was successfully accomplished. Lead adsorption from water was carried out using functionalized MWCNTs and measured by flame atomic absorption spectrometry (FAAS). The effects of pH, shaking time, initial metal ion concentration, and adsorbent dosage on the adsorption process were studied via batch method. The results obtained showed that removal of lead ions strongly depended on the pH. Desorption study revealed that lead ions adsorbed on the functionalized MWCNTs could be desorbed at pH 3 due to breakage of complexes formed on the sorbent surface. Maximum adsorption capacity of the sorbent under the optimal conditions was 43 mg/g. This favorable adsorption capacity suggests that functionalized carbon nanotubes can be applied for removal of lead from water solutions. The data obtained were fitted with the Langmuir and Freundlich isotherm adsorption models and Langmuir model showed better agreement with the experimental data.

Polyvinylbenzyl Tris-Aminodicarboxylate Microspheres for the Optical Sensing of Cu²⁺Ions

In this work, a tris(2-aminoethyl)aminodicaboxylate functionality was substituted for the chloride of polyvinyl-benzyl chloride (PVBC) which was lightly cross-linked (2%) with divinyl benzene. The resulting derivatized polymer microspheres were embedded in a hydrogel matrix of poly vinyl alcohol cross-linked with glutaraldehyde to produce a sensing membrane. The latter responded selectively to Cu2+ solutions of different concentration ranges (1 × 10-4 M to 1 × 10-6 M). The response is based on the interaction between the metal cations and the negatively charged deprotonated dicarboxylate functional group, which led to neutralization of the charges. As a result, an increase in the turbidity of the sensing membrane occurred which is attributed to a change in the refractive index of the derivatized polymer microspheres relative to that of the hydrogel. The change in the turbidity of the sensing membrane was measured as absorbance using a conventional spectrophotometer. It was found that Cu2+ ions bind to the aminodicarboxylated-polymer with a formation constant, Kf, of 1 × 105 M-1. SEM, Eds and IR analyses were performed on the aminodicarboxylated microspheres and their Cu2+ complex.

Synthesis and Crystal Structure of[（2 , 4-Me2C5H5）2NdC ＝CC6H5]2

he reaction of (2, 4-C_7H_11)_3Nd with HC=CC_6H_5 in toluene leads to [(2, 4-C_7H_11)_2NdC = CC_6H_5]_2 , which crystallizes in the space group P_cab with unit cell pa-rameters a=1 . 0489 (11), b=1.8033 (12), c=2. 1064 (15)nm and Z=4 , least-squares refinement based on 2323 observed reflections converged to a final R valueof 0. 08. The molecular structure shows that the complex is a dimer, in which two(2,4-C_7H_11)_2Nd units are connected by asymmetrical alkynide bridges with indepen-dent Nd-C(alkynide) bond lengths of 0. 2552(25)and 0. 2560(24)nm, Nd-C=C angles of 124. 1(17)° and 134. 2(17)°.

SYNTHESIS AND POLYMERIZATION OF TRI(2-PYRIDYL)METHYL METHACRYLATE

A novel methacrylate monomer with bulky side group, tri(2-pyridyl)methyl methacrylate (Tr2PyMA), was synthesized and polymerized. The polymer obtained by radical polymerization exhibits high isotactic tacticity.

Comparative Efficacy of Polyamine-Based Scavenger Resins

Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes) from solutions has been studied. As expected, the scavenging efficiency is directly proportional to the number of nucleophic nitrogens present on the resin. The results have been compared with the performance of the popular scavenger resin, namely, tris(2-aminoethyl)amine resin, to conclude that the low-cost polyamine resins now prepared can be conveniently used as effectively as the expensive commercial product.

Stable Diarylamine-Substituted Tris(2,4,6-trichlorophenyl)methyl Radicals: One-Step Synthesis, Near-Infrared Emission, and Redox Chemistry

A mild one-step radical-to-radical synthetic strategy has been developed to directly produce a new family of diarylamine-substituted tris(2,4,6-trichlorophenyl)methyl(TTM)radicals TTM-DPA,TTM-DBPA,and TTM-DFA.The obtained TTM radical derivatives are extremely stable during chromatography purification and long-term storage in the solid state.

The Influence of Aziridine on the Aging of Composite Solid Rocket Propellant

Aging of a solid composite propellant containing HTPB/AP/AL was performed in order to validate the conformance of the accelerated aging data to the Arrhenius law. The main objective of the work was to examine the influence of the aziridine bonding agents family on the propellant aging. Aging of the prepared propellant samples was conducted as follows: 1. Four samples, one free of bonding agents, and three containing aziridine based bonding agents MAPO,HX-752, MAT4 were aged at 65°C. 2. Another four samples based on HX-752, MAT4 with different curing agents were aged at 65°C. The measured mechanical properties of the free bonding agent propellant samples were very far from the specifications and this illustrates the importance of the bonding agents in both the preparation and the aging phases.The prepared bonding agent 'MAT4' gave remarkable improvements of the mechanical properties comparing with HX-752 and MAPO. The aziridine bonding agents family inhibited the rate of decomposition of the propellant during the aging periods and supported the propellant matrix against decomposition at the elevate temperatures. Using of HMDI as curing agent gave slight better mechanical properties to the IPDI.

UV/H2O2 oxidation of tri(2-chloroethyl) phosphate: Intermediate products, degradation pathway and toxicity evaluation

Tri(2-chloroethyl) phosphate(TCEP) with the initial concentration of 5 mg/L was degraded by UV/H2O2 oxidation process. The removal rate of TCEP in the UV/H2O2 system was 89.1% with the production of Cl-and PO4^3- of 0.23 and 0.64 mg/L. The removal rate of total organic carbon of the reaction was 48.8% and the pH reached 3.3 after the reaction. The oxidative degradation process of TCEP in the UV/H2O2 system obeyed the first order kinetic reaction with the apparent rate constant of 0.0025 min^-1( R^2 = 0.9788). The intermediate products were isolated and identified by gas chromatography-mass spectrometer. The addition reaction of HO · and H2O and the oxidation reaction with H2O2 were found during the degradation pathway of 5 mg/L TCEP in the UV/H2O2 system. For the first time, environment risk was estimated via the "ecological structure activity relationships" program and acute and chronic toxicity changes of intermediate products were pointed out. The luminescence inhibition rate of photobacterium was used to evaluate the acute toxicity of intermediate products. The results showed that the toxicity of the intermediate products increased with the increase of reaction time, which may be due to the production of chlorine compounds. Some measures should be introduced to the UV/H2O2 system to remove the highly toxic Cl-containing compounds, such as a nanofiltration or reverse osmosis unit.

Chlorinated organophosphate and“legacy”brominated flame retardants in UK waste soft furnishings:A preliminary study

The Furniture and Furnishings(Fire Safety)Regulations 1988 is the major driver for the use of chemical flame retardants(FRs)in soft furnishings marketed in the UK.While these regulations specify the level of flame retardancy required,they do not specify how such levels should be achieved.Consequently,it remains unclear which FRs are present in UK soft furnishings.This is important not only to help assess what FRs we may be exposed to currently,but which FRs are currently entering the waste stream with concomitant potential for release into the environment.To address this data gap,concentrations of polybrominated diphenyl ethers(PBDEs),hexabromocyclododecane(HBCDD)and a range of chlorinated organophosphate flame retardants(OPFRs)were measured in samples of domestic and office waste soft furnishings products entering the UK waste stream in 2011 and 2012.This preliminary study measured the FR content of:carpets(n?4),curtains(n?7),mattress fabrics(n?2),furniture foam(n?9),and furniture upholstery textiles(n?10).Polybrominated diphenyl ethers(PBDEs)and hexabromocyclododecane(HBCDD)were not found at significant concentrations(below detection limits in most samples)in any of the twenty two analysed products.In contrast,7 of the 9 furniture foam samples were treated with tris(2-chloroisopropyl)phosphate(TCIPP)at a mean concentration of 1.9%w/w,with another single foam sample containing tris(1,3-dichloroisopropyl)phosphate(TDCIPP)and tris(2-chloroethyl)phosphate(TCEP)at 1.1 and 0.5%respectively.By comparison,PBDE concentrations are within the range reported previously for UK indoor dust[18],rather than the percent by weight levels required to impart flame retardancy.