Structural development Of TMMA and SSQXN‐8 as porous chelating resins

Abstract

Superfast kinetics of Nd þ3 , Eu þ3 , and Gd þ3 ions were studied on the surfaces of N, N, N \ , N \ -tetramethylmalonamide (TMMA) and silsesquioxane resins. TMMA and SSQXN-8 were prepared by suspension polymerization and sol-gel routes, respectively. They were identified using elemental analysis, FTIR, H-NMR, 13 C-NMR, MIP, and BET surface area. Kinetic investigations were performed in batch conditions and different models were used to fit the data; Boyd and Helfferich models were found the best. The diffusion of the ions through the resins were very fast and found to be in the order of 10 À16 m 2 /S. Effective diffusions of the studied ions were found to be 10 À15 order of magnitude and directly proportional to the kinetic energy of the transition state. DS* values from À166.044 to À179.297 J mol À1 K À1 were estimated as entropy stability factors of the system.

Recent Developments in the Chemistry of Cubic Polyhedral Oligosilsesquioxanes

“…742,743 The triazole derivative, 69, has also been found to be highly porous having a surface area, as measured using the BET method, variously measured at 1200 121 and 862 m 2 g -1 . 124 Such measurements are prone to variable results, often due to differences in sample preparation, but in either case, a high surface area may lead to applications in gas capture or storage or capture of metal ions. 124 Dielectric relaxation spectroscopy and dynamic mechanical spectroscopy studies of T 8 [OSiMe 2 (CH 2 ) 3 OCH 2 CH(O)CH 2 ] 8 and of compound 16 show that both undergo two relaxation processes, which both increase in frequency as the temperature is increased.…”

“…124 Such measurements are prone to variable results, often due to differences in sample preparation, but in either case, a high surface area may lead to applications in gas capture or storage or capture of metal ions. 124 Dielectric relaxation spectroscopy and dynamic mechanical spectroscopy studies of T 8 [OSiMe 2 (CH 2 ) 3 OCH 2 CH(O)CH 2 ] 8 and of compound 16 show that both undergo two relaxation processes, which both increase in frequency as the temperature is increased. The dielectric strength increases for one of the processes with increasing temperature but decreases for the other process.…”

“…The conductivity, permittivity, and capacitance of poly(propyl methacryl-heptaisobutyl-POSS- co - N -butyl methacrylate) containing 15−25% of POSS cage by weight have been measured in order to assess the suitability of such materials as humidity sensors. Pores within the material that can host water molecules are thought to increase the conductivity. , The triazole derivative, 69 , has also been found to be highly porous having a surface area, as measured using the BET method, variously measured at 1200 and 862 m 2 g −1 . Such measurements are prone to variable results, often due to differences in sample preparation, but in either case, a high surface area may lead to applications in gas capture or storage or capture of metal ions …”

Recent Drifts in pH-Sensitive Reverse Osmosis

“…where Q is the amount of metal ion, K F is the Freundlich equilibrium constant (mg 1Àn g À1 l n ), Y i is the metal free in solution (mg/l), and n is a constant. Freundlich equation gives a linear form [58][59][60][61][62]: Figure 7 displays the linear regression fits of the Langmuir isotherm to the data obtained for particular metal ions in solution with PAm at pH 3 upon PAm-ZTS surface. The Langmuir isotherm fitted the test data very well (R 2 values >0.98).…”

Functionalized polyhedral oligomeric silsesquioxane (POSS) for incorporation of chemically pendant chains = Utilização de silsesquioxanos oligoméricos poliédricos funcionalizados (POSS) no ancoramento de cadeias orgânicas à superfície

“…The results obtained were almost similar to those obtained by the previous reports, where Ibrahim et. al, and other researchers 15,22,[140][141][142][143] reported 31-37 % yield.…”