|
Thesis
/ | ROMDOC-THESIS-2017-1016 |
Transportul ionului de plumb prin membrane celulozice şi compozite
Iarca, Ludmila Georgeta
2011-12-23
Abstract: Transportul ionului de plumb prin membrane celulozice şi compozite Avantajele derivaţilor acetilaţi ai celulozei constau în obţinerea unor membrane cu flux şi selectivitate ridicate, tehnologie de fabricare accesibilă, materii prime abundente şi regenerabile. Dezavantajele acestor polimeri sunt rezistenţa termică scăzută; interval optim de pH îngust (2÷8), limitând aplicaţiile la sisteme apoase cu conţinut scăzut de săruri; rezistenţă mică la oxidare cu clor (ceea ce restrânge utilizarea în domeniul apei potabile); membranele trebuie păstrate în stare umedă şi sunt biodegradabile, ceea ce impune utilizarea în medii sterile. Aceste dezavantaje au impus studierea a noi materiale polimerice si compozite pentru confecţionarea membranelor. Prezenta plumbului in solutii de solventi organici reprezinta un impediment in utilizarea acestora in anumite tipuri de aplicatii unde se cer conditii de puritate avansata (industrie alimentara, medicina, electronica, chimia analitica, optica). In vederea indepartarii, prin nanofiltrare, a plumbului sau a urmelor de ioni de plumb, din solutii apoase etanolice, acest articol prezinta sinteza membranelor de celuloza cu eteri coroana imobilizati, pe suprafata. Imobilizarea s-a realizat dupa activarea alcalina a membranei de celuloza si legarea covalenta a derivatilor amino eter coroana (utilizand clorura de cianuril drept molecula de spatiere intre membrana si eterul coroana). Materialele sintetizate au fost caracterizate prin spectroscopie FT-IR si microscopie SEM si testate la indepartarea prin nanofiltare a ionilor de plumb din solutii etanolice apoase, simuland astfel produse spirtoase obtinute prin distilore in vase artizanale ce contin plumb. Lead Ion Transport Through Cellulosic and Composite Membranes The advantages of acetylated derivatives of cellulose membranes consist in obtaining of high flux and selectivity, accessible manufacturing technology, abundant and renewable raw materials . The disadvantages of these polymers are represented by low thermal resistance, pH optimum narrow (2 ÷ 8), limiting the applications to aqueous systems with low-salt containing, low resistance to oxidation by chlorine (which restricts the use in drinking water), membranes must be kept wet and are biodegradable, which requires the use in sterile environments. These disadvantages are required to study new polymeric and composite materials for making membranes. The presence of lead in organic solvents is an impediment to their use in certain types of applications where conditions require advanced purity (electronics, medicine, analytical chemistry, optics). In order to remove the lead or traces of lead ions, by nanofiltration, from aqueous ethanol solutions, this paper shows the synthesis of cellulose membranes with crown ethers immobilized on the membrane surface. Immobilization was achieved after alkaline activation of cellulose membrane and immobilization of amino derivatives of crown ethers (using cyanuric chloride as spacing molecule between the membrane and crown ether). Synthesized materials were characterized by FT-IR spectroscopy and SEM microscopy and were tested to remove the lead ions from aqueous ethanol solutions by nanofiltration, simulating on this was alcoholic products obtained by distillation in vessels with lead contain CONDUCĂTOR ŞTIINŢIFIC DOCTORAND Prof. Dr. Ing. Gheorghe NECHIFR Ing. Ludmila Georgeta IARCA (STRATAN)
Keyword(s): Membrane -- Procese chimice -- Teză de doctorat ; Membrane lichide -- Teză de doctorat ; Membrane compozite -- Teză de doctorat ; Plumb -- Depoluare -- Teză de doctorat
OPAC: See record in BC-UPB Web OPAC
Full Text: see files
Record created 2017-02-27, last modified 2017-02-27
Similar records
| People who viewed this page also viewed: |
|
|
Be the first to review this document.
Start a discussion about any aspect of this document.
guest ::