20.500.12556/DKUM-99965 Vpliv ultrazvoka na porozno strukturo raft akrilatnih polimerov The effect of ultrasound on the porous structure of raft acrylate polymers V diplomskem delu smo preučevali vpliv ultrazvočne obdelave emulzij z visokim deležem notranje faze (HIPE) na morfologijo visoko poroznih poliHIPE akrilatnih polimerov, pripravljenih s prosto radikalsko polimerizacijo in RAFT polimerizacijo. Namen raziskave je bil ugotoviti, kako polimerizacijski mehanizem, monomerna sestava ter ultrazvočna obdelava vplivajo na stabilnost emulzij in morfološke lastnosti končnih materialov po polimerizaciji. PoliHIPE materiale smo sintetizirali iz trimetilolpropan triakrilata (TMPTA) in 2-etilheksil akrilata (EHA) pri različnih molskih razmerjih, njihove kemijske in morfološke lastnosti pa smo ovrednotili s FTIR spektroskopijo, vrstično elektronsko mikroskopijo (SEM) ter analizo adsorpcije/desorpcije dušika po BET modelu. Rezultati so pokazali, da ultrazvočna obdelava pomembno vpliva na morfologijo poliHIPE materialov. Pri vzorcih, pripravljenih s prosto radikalsko polimerizacijo, je kratkotrajna ultrazvočna obdelava (3 min) povzročila znižanje velikosti por, medtem ko je daljša sonifikacija (5 min) vodila do izrazitega zmanjšanja por oziroma do destabilizacije emulzij. Stabilnost sistema je bila močno odvisna tudi od molskega razmerja TMPTA in EHA. Pri RAFT polimerizaciji so osnovni poliHIPE materiali izkazovali večje primarne pore (do 75 µm) kot materiali, pripravljeni s prosto radikalsko polimerizacijo (do 18 µm). Sonifikacija je pri teh sistemih učinkovito zmanjšala velikost por (do 1 µm) in izboljšala odprtocelično strukturo, vendar je daljši čas obdelave prav tako povzročil destabilizacijo emulzij in njihov razpad. PoliHIPE materiali, pripravljeni z RAFT polimerizacijo, so zaradi prisotnosti mezo por dosegali višje BET specifične površine (do 75 m2/g) kot materiali, pripravljeni s prosto radikalsko polimerizacijo (do 46 m2/g). Čeprav je sonifikacija zmanjšala velikosti primarnih por in povečala odprtost por, se to pri RAFT materialih ni odrazilo v povečanju BET specifične površine, medtem ko je bil ta učinek izrazitejši pri materialih, pripravljenih s prosto radikalsko polimerizacijo. FTIR analiza je potrdila prisotnost značilnih funkcionalnih skupin, pričakovanih v strukturi poli(TMPTA-ko-EHA) materialov, s čimer je bila potrjena uspešna sinteza ciljnega polimera. Raziskava je pokazala, da sonifikacija predstavlja učinkovito metodo za uravnavanje morfologije poliHIPE materialov, pri čemer je ključen čas obdelave in sestave emulzijskega sistema. This thesis investigated the effect of ultrasonic treatment of high internal phase emulsions (HIPEs) on the morphology of highly porous polyHIPE acrylate polymers prepared by free radical polymerization and RAFT polymerization. The aim of the study was to determine how the polymerization mechanism, monomer composition, and ultrasonic treatment affect emulsion stability and the morphological properties of the final materials after polymerization. PolyHIPE materials were synthesized from trimethylolpropane triacrylate (TMPTA) and 2-ethylhexyl acrylate (EHA) at different molar ratios, and their chemical and morphological properties were evaluated using FTIR spectroscopy, scanning electron microscopy (SEM), and nitrogen adsorption/desorption analysis according to the BET method. The results showed that ultrasonic treatment significantly affects the morphology of polyHIPE materials. In samples prepared by free radical polymerization, short term ultrasonic treatment (3 min) resulted in a decrease in pore size, whereas prolonged sonification (5 min) led to a pronounced reduction in porosity or destabilization of the emulsions. The stability of the system was also strongly dependent on the TMPTA-to-EHA molar ratio. In samples prepared by RAFT polymerization, the initial polyHIPE materials exhibited larger primary pores than those prepared by free radical polymerization (up to 72 µm and 18 µm, respectively). Sonification effectively reduced the pore size in these systems (down to 1 µm) and improved the open-cell structure; however, prolonged treatment also resulted in emulsion destabilization and breakdown. PolyHIPE materials prepared by RAFT polymerization exhibited higher BET specific surface areas (up to 75 m²/g) than materials prepared by free radical polymerization (up to 46 m²/g), which can be attributed to the presence of mesopores. Although sonification reduced the size of the primary pores and increased pore openness, this was not reflected in an increase in the BET specific surface area of the RAFT materials, whereas this effect was more pronounced in materials prepared by free radical polymerization. FTIR analysis confirmed the presence of the characteristic functional groups expected in the structure of the poly(TMPTA-co-EHA) materials, confirming the successful synthesis of the target polymer. The study demonstrated that sonification represents an effective method for controlling the morphology of polyHIPE materials, with the treatment time and composition of the emulsion system being key factors. poliHIPE RAFT polimerizacija prosta radikalska polimerizacija ultrazvočna obdelava porozni polimeri akrilatni polimeri polyHIPE RAFT polymerization free radical polymerization ultrasonic treatment porous polymers acrylate polymers true true false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-08-31 23:15:39 2026-09-11 08:06:19 2026-09-12 03:05:08 0000-00-00 00:00:00 2026 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 UN_Dautovic_Ema_2026.pdf UN_Dautovic_Ema_2026.pdf 1 705F7B94D4F9854E30F2A8E84DCC375A 58600f7a73572353ba5887d044baef552cf2d826bed66f423c302231d07a16ea cc81ec46-ad15-11f1-b668-00155d0001be https://dk.um.si/Dokument.php?lang=slv&id=212100 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0