Odstranjevanje ionov težkih kovin iz vodnih raztopin s pomočjo sintetiziranih amino sol-gel nanodelcev

diplomsko delo

Sara Krajnc (Author), Aleksandra Lobnik (Mentor), Maja Bauman (Co-mentor)

Abstract

Površinsko funkcionalizirani nanodelci silicijevega dioksida (SiO2) so v zadnjem času predmet številnih raziskav, ki obravnavajo odstranjevanje ionov težkih kovin iz različnih vodnih medijev. Nanodelci SiO2 se izkazujejo kot primerni zaradi svoje inertnosti, biokompatibilnosti, specifične površine in poroznosti, možnosti obdelave (funkcionaliziranja) površine ter enostavne in cenovno ugodne priprave. V diplomskem delu smo za pripravo amino-funkcionaliziranih SiO2 nanodelcev (SiO2@NH2) uporabili Stöber-jevo metodo, ki vključuje reakciji hidrolize in kondenzacije alkoksidnih prekurzorjev, kot sta tetraetoksisilan (TEOS) in 3-(trimetoksisililpropil) dietilentriamin (DETA), v alkoholnem mediju ob prisotnosti amoniaka kot katalizatorja. Na funkcionalnost pripravljenih SiO2 nanodelcev so vplivali sintezni pogoji (temperatura, čas, molsko razmerje voda:prekurzor, molsko razmerje med prekurzorji) in izbor prekurzorja, ki s svojimi amino (-NH2) funkcionalnimi skupinami omogoča vezavo in odstranjevanje ionov težkih kovin. Pripravljeni SiO2 in amino-funkcionalizirani SiO2 nanodelci (SiO2@NH2) so bili karakterizirani z uporabo različnih tehnik, kot so FT-IR spektroskopija, specifična površina (BET), presevna elektronska mikroskopija (TEM) in meritve zeta potenciala. S sintetiziranimi nanodelci smo proučevali učinkovitost vezave in odstranjevanja (adsorpcija) ionov težkih kovin, svinca (Pb2+) in kroma (Cr3+), iz modelnih raztopin soli. Učinkovitost odstranjevanja ionov težkih kovin je temeljila na osnovi meritev atomske absorpcijske spektroskopije (AAS). Rezultati so pokazali višjo tendenco vezave sintetiziranih SiO2 nanodelcev do Cr3+ ionov (~60%), v primerjavi z vezavo Pb2+ ionov (~33%), medtem ko je bila tendenca funkcionaliziranih SiO2 nanodelcev do obeh kovin približno enaka (~50%).

Keywords

sol-gel nanodelci;tetraetoksisilan;3-(trimetokisisililpropil)dietilentriamin;učinek adsorpcije;ioni težkih kovin;modelna raztopina soli;cink;svinec;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2015
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	[S. Krajnc]
UDC:	628.161.2:620.3(043.2)
COBISS:	19286806
Views:	1716
Downloads:	201
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Removal of heavy metals ions from aqueous solutions with amino sol-gel synthesized nanoparticles
Secondary abstract:	Recently, surface-functionalized silicon dioxide (SiO2) nanoparticles are the subject of numerous research studies, which discuss the removal of heavy metal ions from different aquatic solutions. SiO2 nanoparticles are proven to be suitable because of their inertness, biocompatibility, specific surface area and porosity, surface treatment options (functionalization), are also simple and affordable. The research work on the preparation of amino-functionalized SiO2 nanoparticles (SiO2@NH2) was based on the Stöber method, which involves the reaction of hydrolysis and condensation of alkoxide precursors, such as tetraethoxysilane (TEOS) and 3- (trimethoxysilylpropyl) diethylenetriamine (DETA) in alcoholic media in the presence of ammonia as a catalyst. The functionality of SiO2 nanoparticles is influenced by synthesis conditions (temperature, time, molecular ratio of water:precursor, molar ration between the precursors) and selection of precursor, which with its amino (-NH2) functional groups allows to bond and remove the heavy metal ions. SiO2 and amino-functionalized SiO2 nanoparticles (SiO2@NH2) were characterized using a variety of techniques, such as FT-IR spectroscopy, specific surface area (BET), transmission electron microscopy (TEM) and zeta potential measurements. We have studied the binding efficiency (adsorption) of heavy metals ions, lead (Pb2 +) and chromium (Cr3+), by nanoparticles, from model salt solutions. Removal efficiency of heavy metal ions was calculated based on the measurements of atomic adsorption spectroscopy (AAS). The results showed a higher tendency towards synthesized SiO2 nanoparticles to Cr3 + ions (~ 60%), compared to the Pb2 + ions (~ 33%), while the tendency of functionalized SiO2 nanoparticles towards both metals was approximately similar (~ 50%).
Secondary keywords:	sol-gel nanoparticles;tetraethoxysilane;3-(trimethoxysilylpropyl)diethylenetriamine;adsorption efficiency;heavy metal ions;model solution;zinc;lead;
URN:	URN:SI:UM:
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za strojništvo
Pages:	XIV, 78 f.
ID:	8888362