Adsorption of Metal Ions on Gallium(III)-Templated Oxine Type of Chemically Modified Chitosan

Inoue, Katsutoshi; Hirakawa, Hiroyuki; Ishikawa, Yoshihiro; Yamaguchi, Tomoo; Nagata, Junji; Ohto, Keisuke; Yoshizuka, Kazuharu

doi:10.1080/01496399608001046

Cited by 32 publications

(12 citation statements)

References 10 publications

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“…The alkali picrates were prepared as described elsewhere [35] by stepwise ad- The percent extraction (E%) has been calculated as:…”

Section: Liquid-liquid Extraction Proceduresmentioning

confidence: 99%

Synthesis and Extraction Studies of Calix[4]-Crown-4 Oxime Derivatives

Akkuş¹,

Aslan²

2017

IJOC

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The article comprises synthesis of calyx[4]-oxa-crown, and calix[4]-thia-crown compounds containing nitrile groups (3a, 3b) and amino groups (4a, 4b) and their corresponding oxime derivatives (5a, 5b) and liquid-liquid extraction studies of these compounds. The oxime derivatives of compounds (5a, 5b) have been synthesized by reacting of di-n-butylamino derivatives of calix[4]-oxa-crown, and calix[4]-thia-crown compounds (4a, 4b) with amphi-chloroglyoxime in methanol-THF. Their cation and anion transfer studies were performed by using liquid-liquid extraction procedure. It has been concluded from the observations that the compound 3a shows a good extraction behavior toward Na + ion in the presence of other metal cations. Whereas, its oxime derivatives transfers all of the metal cations used in the liquid-liquid extraction studies.

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“…The alkali picrates were prepared as described elsewhere [35] by stepwise ad- The percent extraction (E%) has been calculated as:…”

Section: Liquid-liquid Extraction Proceduresmentioning

confidence: 99%

Synthesis and Extraction Studies of Calix[4]-Crown-4 Oxime Derivatives

Akkuş¹,

Aslan²

2017

IJOC

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“…The metal templates are removed from the chitosan structure by rinsing with diluted acid solution, leaving specific cavities that are only accessible to the intended metal ions. For example, Ga(III) (Inoue et al 1996), Cu(II) (Cao et al 2004) and Pb(II) (Sun et al 2006;Wang et al 2010a) …”

Section: Chitosan Modificationmentioning

confidence: 99%

Environmental Applications of Chitosan and Its Derivatives

Yong

Shrivastava

Srivastava

et al. 2014

Reviews of Environmental Contamination and Toxicology

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Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity, hydraulic conductivity, permeability, surface area and sorption capacity. Crosslinked chitosan is an excellent sorbent for trace metals especially because of the high flexibility of its structural stability. Sorption of trace metals by chitosan is selective and independent of the size and hardness of metal ions, or the physical form of chitosan (e.g., film, powder and solution). Both -OH and -NH2 groups in chitosan provide vital binding sites for complexing metal cations. At low pH, -NH3 + groups attract and coagulate negatively charged contaminants such as metal oxyanions, humic acids and dye molecules. Grafting certain functional molecules into the chitin structure improves sorption capacity and selectivity for remediating specific metal ions. For example, introducing sulfur and nitrogen donor ligands to chitosan alters the sorption preference for metals. Low molecular weight chitosan derivatives have been used to remediate metal contaminated soil and sediments. They have also been applied in permeable reactive barriers to remediate metals in soil and groun...

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“…No entanto, torna-se muito mais atrativo o uso de quitosana quando acontece a modificação química no grupo amino, condições em que podem ser adicionadas outras moléculas, as quais trazem grupos básicos, para dispor de cadeias pendentes com maior potencialidade em remover cátions de soluções. Desta forma, tornase atrativa a quitosana modificada com acetilacetona 108 , hidroxibenzil 109 , ácido oxo-glutárico 110 , oxina 111,112 , derivados do ácido tetraacético 113 , piridilmetilideno 114 e derivado de formil-fenol 115 . Como se nota, várias são as aplicações que podem ser incre- mentadas com a quitosana, que tem sua aplicação tanto em forma de pó, como esferas ou filmes, dependendo das especificações desejadas.…”

Section: Interações Metal/centros Básicosunclassified

A relevante potencialidade dos centros básicos nitrogenados disponíveis em polímeros inorgânicos e biopolímeros na remoção catiônica

Airoldi¹

2008

Quím. Nova

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cation removal by using nitrogenated basic centers. The data demonstrate the importance of the desired groups when free or immobilized on natural or synthesized inorganic polymers through silanol groups. Thus, the most studied silica gel is followed by natural crysotile and talc polymers, and the synthesized mesopore silicas, talc-like, silicic acids, phosphates and phyllosilicates. The organic natural biopolymeric chitin and cellulose were chemically modified to improve the availability of the amine groups or the reactivity with desirable molecules to enlarge the content of basic centers. The cation removal takes place at the solid/liquid interface and some interactive effects have their thermodynamic data determined.Keywords: inorganic polymer; biopolymer; cation removal. INTRODUÇÃONos dias de hoje, quando se veicula assuntos relacionados com superfícies, principalmente na área de Química Inorgânica, os interessados se voltam mais diretamente à rotulação dos profissionais atuantes como químicos de materiais. Porém, muitas vezes são esquecidos os aspectos envolvendo as ligações efetuadas entre os átomos, que estão em quantidade maiores ou menores na formação do esqueleto polimérico. Mesmo sem o conhecimento de tais detalhes e ainda sobre a estrutura é possível empregar o material em atividades tanto acadêmicas como tecnológicas, sendo comumente destacada a propriedade da adsorção. Curiosamente, o material derivado da queima ou extraído de minas naturais, após tratamento, deriva o chamado carvão ativado, o qual foi o primeiro material usado para a remoção de metais pesados contidos em efluentes industriais. No entanto, em qualquer processo operacional, o custo envolvido precisa ser examinado para que seja viável o uso, pois o preço cresce em função das especificidades requeridas e, de fato, a purificação é bastante relevante, o que chega a inviabilizá-lo na adsorção, mas que possibilita o emprego mais amplo somente em pequenas escalas laboratoriais 1 . Diante dos aspectos econômicos limitantes na obtenção do carvão de alta pureza, as pesquisas foram paulatinamente direcionadas para outras fontes alternativas. Um ponto marcante neste estudo foi buscar materiais naturais de baixo custo, que pudessem ter alta capacidade de adsorção, o que implicava na existência de centros quimicamente ativos na superfície, para que pudessem atuar com alta eficiência na retenção de cátions indesejáveis existentes em um leito aquoso contaminado. Nesta direção, o progresso do campo passou a ser mais eficaz após o conhecimento das funções quí-micas disponíveis nas superfícies dos materiais e possíveis tipos de ligações que poderiam formar frente a um determinado soluto, no decorrer do processo de adsorção na interface sólido/líquido 2 . Uma maneira de se obter o material com baixo custo é explorar fontes amplamente encontradas na natureza, que exijam operações simples para chegar a um composto final de composição definida e de alta pureza, fato que nem sempre é alcançado. Dentre uma série de materiais, os zeólitos se ajustam com essas...

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Adsorption of Metal Ions on Gallium(III)-Templated Oxine Type of Chemically Modified Chitosan

Cited by 32 publications

References 10 publications

Synthesis and Extraction Studies of Calix[4]-Crown-4 Oxime Derivatives

Synthesis and Extraction Studies of Calix[4]-Crown-4 Oxime Derivatives

Environmental Applications of Chitosan and Its Derivatives

A relevante potencialidade dos centros básicos nitrogenados disponíveis em polímeros inorgânicos e biopolímeros na remoção catiônica

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