Nitrogen Containing Organosilicon Bonded an Al2O3-Cellulose Acetate Hybrid Material: Preparation, Characterization and Use for Adsorption of Fe(III), Cu(II) and Zn(II) from Ethanol Solutions

This work describes the preparation and characterization of a cellulose acetate fiber coated with Al2O3, resulting in the organic-inorganic hybrid Cella/Al2O3. Furthermore, it was modified by attaching organofunctional groups, by reaction with the precursor reagents (RO)3Si(CH2)3L (L = -NH2, NH(CH2)2NH2, NH(CH2)2NH(CH2) 2NH2 and NC3H3N), resulting in Cella/Al2O3/Si(CH2 )3NH2 (1), Cella/Al2O3/Si(CH2 )3NH(CH2)2NH2 (2), Cella/Al2O3/Si(CH 2)3NH(CH2)2 NH(CH2)2NH2 (3) and Cella/Al2O3/Si(CH2 )3NC3H3N (imidazole) (4). The amount of attached organofunctional groups were (in mmol per gram of the material): 1 = 1.90, 2 = 1.89, 3 = 1.66 and 4 = 1.35. The adsorption isotherms from ethanol solutions of FeCl3, CuCl2 and ZnCl2 by Cella/Al2O3/Si(CH2 )3L were obtained at 298 K. The results obtained in flow experiments showed a retention and recovery of ca. 100% of the metal ions by Cella/Al2O3/Si(CH2 )3L packed in a column, for a solution containing either one or mixture of the ions.Este trabalho descreve a preparação e a caracterização da fibra acetato de celulose recoberta com Al2O3, resultando no híbrido orgânico-inorgânico Cella/Al2O3. Posteriormente, este híbrido foi modificado, imobilizando-se grupos organofuncionais, através da reação com o precursor (RO)3Si(CH2)3L (L = -NH2, -NH(CH2)2NH2, -NH(CH2)2NH(CH2) 2NH2 e -NC3H3N), o que resultou nos materiais Cella/Al2O3/Si(CH2 )3NH2 (1), Cella/Al2O3/Si(CH2 )3NH(CH2)2NH2 (2), Cella/Al2O3/Si(CH2 )3NH(CH2)2NH(CH 2)2NH2 (3) e Cella/Al2O3/Si(CH2 )3NC3H3N (imidazol) (4). A quantidade de grupos organofuncionais ligados foram (em mmol por grama de material): 1 = 1,90, 2 = 1,89, 3 = 1,66 e 4 = 1,35. As isotermas de adsorção das soluções etanólicas de FeCl3, CuCl2 e ZnCl2 por Cella/Al2O3/Si(CH2 )3L foram obtidas à 298 K. Os resultados obtidos pela análise em fluxo mostraram uma retenção e recuperação de praticamente 100% dos íons metálicos na coluna empacotada com Cella/Al2O3/Si(CH2 )3L, para uma solução contendo apenas um ion ou uma mistura de íons.8894Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

The ion exchange properties and equilibrium constants of Li+, Na+ and K+ on zirconium phosphate highly dispersed on a cellulose acetate fibers surface

Highly dispersed zirconium phosphate was prepared by reacting celullose acetate/ZrO2 (ZrO2 = 11 wt%, 1.0 mmol g-1 of zirconium atom per gram of the material) with phosphoric acid. High power decoupling magic angle spinning (HPDEC-MAS) 31P NMR and X-ray photoelectron spectroscopy data indicated that HPO4(2-) is the species present on the membrane surface. The specific concentration of acidic centers, determined by ammonia gas adsorption, is 0.60 mmol g-1. The ion exchange capacities for Li+, Na+ and K+ ions were determined from ion exchange isotherms at 298 K and showed the following values (in mmol g-1): Li+= 0.05, Na+= 0.38 and K+= 0.57. Due to the strong cooperative effect, the H+/Na+ and H+/K+ ion exchange is of non ideal nature. These ion exchange equilibria were treated with the use of models of fixed tridentate centers, which consider the surface of the sorbent as polyfunctional sorption centers. Both the observed ion exchange capacities with respect to the alkaline metal ions and the equilibrium constants are discussed by taking into consideration the sequence of the ionic hydration radii for Li+, Na+ and K+. The matrix affinity for the ions decreases with increasing the cations hydration radii from K+ to Li+. The high values of the separation factors S Na+/Li+ and S K+/Li+ (up to several hundreds) support the application of this material for the quantitative separation of Na+ and K+ from Li+ from a mixture containing these three ions.Fosfato de zircônio altamente disperso foi preparado reagindo acetato de celulose/ZrO2 (ZrO2 = 11 wt%, 1,0 mmol g-1 de átomo de zircônio por grama de material) com ácido fosfórico. Os dados de RMN 31P (HPDEC-MAS) com rotação de ângulo mágico desacoplado e Espectroscopia de Fotoelétron de raios-X indicam que a espécie HPO4(2-) está presente na superfície da membrana. A concentração específica de centros ácidos, determinada pela adsorção de gás amônia, foi de 0,60 mmol g-1. As capacidades de troca-iônica dos íons Li+, Na+ e K+ foram determinadas das isotermas de troca-iônica à 298 K e mostraram os seguintes valores ( em mmol g-1): Li+ = 0,05, Na+ = 0,38 e K+ = 0,57. Devido ao forte efeito cooperativo a troca-iônica de H+/Na+ e H+/K+ apresentou natureza não ideal. Esse equilíbrio de troca-iônica foi tratado com o uso de modelos de centros bi ou tridentados que considera a superfície do sorvente como centros de sorção polifuncionais. Tanto as capacidades de troca-iônica observadas com os respectivos íons metálicos alcalinos quanto as constantes de equilíbrio foram discutidas considerando a seqüência dos raios de hidratação iônicos para Li+, Na+ e K+. As afinidades para os íons diminuem com o aumento do raio de hidratação dos cátions, por ex. Li+< Na+ < K+ . Os altos valores dos fatores de separação de S Na+/Li+ e S K+/Li+ permitem aplicar este material para a separação quantitativa de Na+ e K+ de Li+ de uma mistura contendo esses três íons.5057Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Nitrogen Containing Organosilicon Bonded an Al2O3-Cellulose Acetate Hybrid Material: Preparation, Characterization and Use for Adsorption of Fe(III), Cu(II) and Zn(II) from Ethanol Solutions

This work describes the preparation and characterization of a cellulose acetate fiber coated with Al2O3, resulting in the organic-inorganic hybrid Cella/Al2O3. Furthermore, it was modified by attaching organofunctional groups, by reaction with the precursor reagents (RO)3Si(CH2)3L (L = -NH2, NH(CH2)2NH2, NH(CH2)2NH(CH2) 2NH2 and NC3H3N), resulting in Cella/Al2O3/Si(CH2 )3NH2 (1), Cella/Al2O3/Si(CH2 )3NH(CH2)2NH2 (2), Cella/Al2O3/Si(CH 2)3NH(CH2)2 NH(CH2)2NH2 (3) and Cella/Al2O3/Si(CH2 )3NC3H3N (imidazole) (4). The amount of attached organofunctional groups were (in mmol per gram of the material): 1 = 1.90, 2 = 1.89, 3 = 1.66 and 4 = 1.35. The adsorption isotherms from ethanol solutions of FeCl3, CuCl2 and ZnCl2 by Cella/Al2O3/Si(CH2 )3L were obtained at 298 K. The results obtained in flow experiments showed a retention and recovery of ca. 100% of the metal ions by Cella/Al2O3/Si(CH2 )3L packed in a column, for a solution containing either one or mixture of the ions

Nitrogen Containing Organosilicon Bonded an Al2O3-Cellulose Acetate Hybrid Material: Preparation, Characterization and Use for Adsorption of Fe(III), Cu(II) and Zn(II) from Ethanol Solutions

This work describes the preparation and characterization of a cellulose acetate fiber coated with Al2O3, resulting in the organic-inorganic hybrid Cella/Al2O3. Furthermore, it was modified by attaching organofunctional groups, by reaction with the precursor reagents (RO)3Si(CH2)3L (L = -NH2, NH(CH2)2NH2, NH(CH2)2NH(CH2) 2NH2 and NC3H3N), resulting in Cella/Al2O3/Si(CH2 )3NH2 (1), Cella/Al2O3/Si(CH2 )3NH(CH2)2NH2 (2), Cella/Al2O3/Si(CH 2)3NH(CH2)2 NH(CH2)2NH2 (3) and Cella/Al2O3/Si(CH2 )3NC3H3N (imidazole) (4). The amount of attached organofunctional groups were (in mmol per gram of the material): 1 = 1.90, 2 = 1.89, 3 = 1.66 and 4 = 1.35. The adsorption isotherms from ethanol solutions of FeCl3, CuCl2 and ZnCl2 by Cella/Al2O3/Si(CH2 )3L were obtained at 298 K. The results obtained in flow experiments showed a retention and recovery of ca. 100% of the metal ions by Cella/Al2O3/Si(CH2 )3L packed in a column, for a solution containing either one or mixture of the ions

Determination Of The Constants Of Affinity Of Fecl3, Cucl2, And Zncl2 For A Nitrogen-containing Organosilane Bonded On Al2o3-cellulose Acetate Hybrid Material Surface From Ethanol Solution.

This work describes the preparation and characterization of a cellulose acetate fiber coated with Al(2)O(3), resulting in the organic-inorganic hybrid Cel/Al(2)O(3). Furthermore, the hybrid was modified by attaching organofunctional groups by reaction with the precursor reagents (RO)(3)Si(CH(2))(3)L (L=NH(2), NH(CH(2))(2)NH(2), NH(CH(2))(2)NH(CH(2))(2)NH(2), and N(2)C(3)H(3) (imidazole)), resulting in Cel/Al(2)O(3)/Si(CH(2))(3)NH(2) (1), Cel/Al(2)O(3)/Si(CH(2))(3)NH(CH(2))(2)NH(2) (2), Cel/Al(2)O(3)/Si(CH(2))(3)NH(CH(2))(2)NH(CH(2))(2)NH(2) (3), and Cel/Al(2)O(3)/Si(CH(2))(3)N(2)C(3)H(3) (4). The amounts of attached organofunctional groups were (in mmol per gram of the material) 1=1.90, 2=1.89, 3=1.66, and 4=1.35. The isotherms of adsorption of FeCl(3), CuCl(2), and ZnCl(2) by Cel/Al(2)O(3)/Si(CH(2))(3)L from ethanol solutions were obtained at 298 K. Accurate estimates of the specific sorption capacities and the heteregeneous stability constants of the immobilized metal complexes were determined with the aid of several computational procedures. It is shown that the sorptional capacities are much less than the concentrations of the attached organofunctional groups. As all sorption isotherms are fitted properly with the Langmuir isotherm equation, the effects of the energetic heterogeneity and the lateral interactions do not affect the chemisorption equilibria. The heterogeneous stability constants of the immobilized complexes are fairly high, which provides efficient removal of the metal ions from solutions by the hybrid materials.25431-