Sinteza nanokompozitnih hidrogelov v porah PP membrane

doktorska disertacija

Manja Kurečič (Author), Majda Sfiligoj-Smole (Mentor), Karin Stana-Kleinschek (Co-mentor)

Abstract

POVZETEK Cilj naloge »Sinteza nanokompozitnih hidrogelov v porah PP membrane« je bil sintetizirati nanokompozitni hidrogel z vključenimi nanodelci mineralov glin v porah PP membrane s sposobnostjo razbarvanja tekstilnih odpadnih vod. V raziskavi smo uporabili organsko modificirane montmorilonit delce (O-MMT), katerih poglavitna lastnost je velika aktivna površina, ki jo dosežemo ob interkalaciji oz. eksfoliaciji silikatnih plasti delcev v hidrogelni matrici. Raziskava je bila razdeljena v tri sklope; Prvi del je zajemal študij lastnosti hidrofobnih delcev dispergiranih v vodi z namenom doseganja stabilne vodne disperzije. Pri tem smo uporabili neionski polisaharidni površinsko aktivni sistem na bazi inulina, za izboljšanje omakalnih sposobnosti delcev glin in izboljšanje njihove sposobnosti dispergiranja v vodnih sistemih. Disperzijam O-MMT različnih koncentracij površinsko aktivnega sredstva smo določali elektrokinetične lastnosti, velikosti delcev in stabilnost disperzije. O-MMT delcem obdelanim s površinsko aktivnim sredstvom smo določali hidrofilno-hidrofoben značaj in strukturo z medoto malokotnega rentgenskega sipanja. V drugem delu smo UV polimerizirali nanokompozitni hidrogel s vključenimi O-MMT nanodelci, pri čemer smo uporabili N-isopropilakrilamid kot monomer ter N,N-metilenbisakrilamid kot zamreževalec. Pri tem smo spremljali vpliv deleža zamreževalca in vključenih nanodelcev v nanokompozitu na stopnjo zamreženja in na stopnjo nabrekanja nanokompozitnega hidrogela. S pomočjo FT-IR spektroskopije smo določili mehanizem polimerizacije in zamreženja hidrogela in z metodo malokotnega rentgenskega sipanja interkalirano/eksfoliirano strukturo delcev v nanokompozitu. Učinkovitost nanokompozitnega hidrogela smo določili s stopnjo adsorbcije kislega barvila C.I. Acid Orange 33 s pomočjo UV/VIS spektroskopije. Proučili smo vpliv pH barvne raztopine, konc. barvila, časa, in deleža O-MMT delcev v nanokompozitu na stopnjo adsorbcije barvila. V tretjem, zadnjem delu smo in-situ polimerizirali nanokompozitni hidrogel v porah hidrofobne polipropilenske (PP) membrane. Za doseganje popolne prekritosti por PP membrane s polimeriziranim nanokompozitnim hidrogelom smo raziskali vpliv različnih postopkov omakanja na delež gela v membrani in hidrofilno/hidrofobni značaj membrane. Sposobnost sintetizirane nanokompozitne PP membrane za razbarvanje raztopine kislega barvila C.I. Acid Orange 33 smo določali z ultrafiltracijo. Raziskave so pokazale, da ima koncentracija PAS velik vpliv na pripravo stabilne vodne disperzije O-MMT delcev. Z uporabo stabilne disperzije O-MMT delcev dobimo razplasteno strukturo nanokompozitnega hidrogela, ki je sposoben adsorbiranja kislega barvila Acid Orange 33. Z višanjem koncentracije delcev v nanokompozitnem hidrogelu se viša stopnja adsorpcije barvila. Z in-situ polimerizacijo smo uspešno pripravili nanokompozitno membrano s vključenimi O-MMT delci razplastenimi v hidrogelni matrici, kar izboljša filtracijsko sposobnost PP membrane za 80%.

Keywords

plasteni silikati;montmorilonit;nanokompozitni hidrogeli;adsorbcija barvil;lastnosti koloidnih sistemov;ultrafiltracija;

Data

Language:	Slovenian
Year of publishing:	2011
Source:	[Maribor
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	M. Kurečič]
UDC:	677.1:544.773.432(043.3)
COBISS:	257400832
Views:	2594
Downloads:	320
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Synthesis of nanocomposite hydrogels in PP membrane pores
Secondary abstract:	ABSTRACT Aim of the presented thesis is to synthesize nanocomposite hydrogel with incorporated nanoparticles of layered silicates inside of the PP membrane pores, with the ability to decolorate textile wastewaters. In our research we have used organically modified monmorillonite particles (O-MMT), which were exfoliated inside the hydrogel matrix in order to achive larger specific surface area. Research work was divided into three parts; first part was focused on the study of properties of hydrophobic clay particles dispersed in water in order to ensure stable aqueous dispersions. We have used a non-ionic polysaccharide-based surfactant system – Inutec SP1 for the improvement of wettability of clay particles, enhancement of their dispersion ability in water-based systems. Properties of the surfactant-stabilized aqueous colloidal system were determined by electrokinetical properties and dynamic light scattering measurements. By modifying surface properties of clay particles with non-ionic surfactant, we have managed to reduce their size. Water contact angles of the particles were determined and particles structure was investigated by small-angle X-ray scattering. Knowledge about electrokinetic properties and scattering data, hydrophobic/hydrophilic character and particles sedimentation behaviour is very important for preparation of functional nanocomposites with exfoliated and intercalated MMT nanoparticles. In second part of the thesis we have UV polymerized nanocomposite hydrogels with incorporated montmorillonite nanoparticles; N-isopropylacrylamide as monomer and N,N.metilenbisacrylamide as crosslinker were used. We have studied the effect of different concentrations of crosslinker and incorporated nanoparticles on the degree of crosslinking and sweeling of nanocomposite hydrogel. Exfoliated and intercalated structure of nanocomposite hydrogels was determined with SAXS. We have also determined nanocomposite hydrogels´ degree of adsorption for C.I. Acid Orange 33 using UV/VIS spectroscopy. We have studied the effect of pH, time, conc. of dye and conc. of incorporated nanoclay particles inside nanocomposite. In the last, third part, we have in-situ polymerized nanocomposite hydrogels inside the hydrophobic polypropylene membrane pores. In order to achive full coverage of PP membrane pores with nanocomposite hydrogels, we have studied the effect of different wetting methods on the amount of gel in the membrane and hydrophilic/hydrophobic character of the membrane. The ability of PP membrane with incorporated nanocomposite hydrogel to decolorate the solution of acid dye C.I. Acid Orange 33 was determined with ultrafiltration. Results show, that concentration of PAS plays important role in preparation of stabile water dispersion of O-MMT particles. In polymerization process of hydrogels, with the use of stabile dispersion of O-MMT particles, we obtain exfoliated structure of nanocomposite hydrogel, with the ability to adsorb acid dye Acid Orange 33. With increasing the concentration of O-MMT particles incorporated in nanocomposite hydrogel the degree of acid dye adsorption is also increasing. In-situ polymerization of nanocomposite hydrogels in side the PP membrane pores represents a useful method, which yields nanocomposite membrane with exceedingly improved filtration properties (80%).
Secondary keywords:	layered silicates;montmorillonite;nanocomposite hydrogels;pp membranes;dye adsorption;ultrafiltration;properties of colloid systems;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. Maribor, Fak. za strojništvo
Pages:	[X], 145 f., [7] f. pril.
Keywords (UDC):	applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;various industries;trades and crafts;razne industrije;obrti in rokodelstva;textile industry;tekstilna industrija;bast fibres (fibres from dicotyledon stems);hard fibres (fibres from monocotyledon leaves and fruit);vlakna iz ličja;stebelna vlakna dvokaličnic;trda listna in plodovna vlakna enokaličnic;mathematics;natural sciences;naravoslovne vede;matematika;chemistry;crystallography;mineralogy;kemija;physical chemistry;fizikalna kemija;chemistry of surface phenomena and colloids;kemija površinskih pojavov in koloidov;
ID:	1015245