Since the discovery of organic conducting polymers more than 20 years ago, these materials are finding an increasing use in various branches of technology, such as metallization of dielectrics, primary and secondary batteries, antistatic coatings, electromagnetic shielding, electrochromic systems. One of the most striking properties of conducting polymers is their ability to catalyze some electrode reactions. A thin layer of a conducting polymer, deposited onto the surface of substrate electrode, is able to enhance the kinetics of electrode processes of some solution species. These electrocatalytic processes, proceeding at conducting polymer electrodes, present a fast growing area of investigation, which may yield many unexpected applications in various fields of applied electrochemistry.

<p>U savremenoj restaurativnoj stomatologiji dentalni kompoziti su materijal izbora za rekonstrukciju izgubljenog čvrstog zubnog tkiva. Kako je u kliničkoj praksi primećeno, pozitivna svojstva svetlosno-aktiviranih dentalnih kompozita su ugrožena pojavom polimerizacione kontrakcije kompozitnih ispuna tokom polimerizacije. Naime, tokom svetlosne polimerizacije usled konverzije molekula monomera u dugačke izukr&scaron;tane lance polimera, razvija se napon na adhezivnom spoju kompozitnog ispuna i zida kaviteta. Kada vrednost napona nadma&scaron;i jačinu adhezivne veze kompozita i zida kaviteta, formira se marginalna mikropukotina praćena kliničkim manifestacijama u vidu postoperativne osetljivosti, marginalne diskoloracije ispuna, razvoja sekundarnog karijesa i sledstvenih ireverzibilnih promena pulpe zuba. Cilj istraživanja je bio da se uporedi uticaj primene različitih tehnika postavljanja i svetlosne polimerizacije na marginalnu adaptaciju kompozitnih ispuna. Materijal i metode: Ispitivanje marginalne adaptacije kompozitnih ispuna urađeno je u dentinskim kavitetima, na bukalnim i oralnim povr&scaron;inama humanih trećih molara u laboratorijskim uslovima. Oralni i bukalni deo krunice zuba je bru&scaron;en dijamantskim diskom uz stalno hlađenje radnog polja vodenim mlazom, kako bi se izložila ravna dentinska povr&scaron;ina promera 4x4 mm. Standardizovani cilindrični dentinski kaviteti, dimenzija 3x3 mm, preparisani su dijamantskim cilindričnim svrdlima uz obilno hlađenje radnog polja mlazom vode. Eksperimentalni deo doktorske teze, imajući u vidu postavljeni cilj istraživanja, podeljen je u dva dela. Prvi deo je obuhvatio ukupno 80 dentinskih kaviteta u koje je postavljen isti kompozitni sistem (Adper Single Bond Plus-Filtek Ultimate Flowable), različitim tehnikama postavljanja: u jednom sloju-bulk tehnikom,&nbsp; inkrementalnom tehnikom, prethodno zagrejani kompoziti i eliminisanjem jedinstvene tačke stresa-postavljanjem pin-a. Za svetlosnu polimerizaciju kompozita primenjene su dve tehnike, kontinuirana i diskontinuirana, odnosno polimerizacija sa prekidom od 10 sekundi (dark interval), nakon inicijalnog perioda prosvetljavanja. Drugi deo istraživanja je obuhvatio 20 istovetnih dentinskih kaviteta u kojima su postavljeni bulk-fill kompozitni sistemi (Filtek Bulk Fill Flowable i SDR) uz kontinuiranu svetlosnu polimerizaciju, prema uputstvu proizvođača. Nakon poliranja ispuna, zubi sa postavljenim ispunima svih grupa su čuvani u uslovima 100 % vlažnosti u trajanju od 24 časa u cilju prevencije dehidratacije. Za evaluaciju marginalne adaptacije kori&scaron;ćena je analiza epoksi replika adhezivnog spoja kompozitnog ispuna i dentina skening elektonskom mikroskopijom (SEM). Naime, nakon uzimanja otiska ispuna i okolnog dentina polivinilsiloksanom izrazito niske viskoznosti (Ghenesyl, Super Light Body, Lascod, Florence, Italy), izlivene su replike u epoksi smoli koje su pripremljene za SEM analizu (Jeol, JSM-6460 Low Vacuum, Tokyo, Japan). Dužina marginalne pukotine je izmerena u mikrometrima pomoću ImageJ računarskog programa (National Institute of Health, Bethesda, USA) i prikazana procentualno u odnosu na ukupnu dužinu marginalnog spoja ispun-dentin. Međusobno su upoređeni rezultati marginalne adaptacije različitih tehnika postavljanja i polimerizacije kompozitnih ispuna kao i rezultati marginalne adaptacije različitih kompozita postavljenih bulk tehnikom i polimerizovanih kontinuirano. Statističke razlike su obrađivane primenom ne-parametrijskog Mann-Whitney U-testa. Rezultati: Analizom numeričkih rezultata utvrđen je statistički značajno vi&scaron;i kvalitet marginalne adaptacije kada su kompozitni sistemi postavljeni u kavitete eliminisanjem jedinstvene tačke stresa-postavljanjem pin-a i diskontinuirano polimerizovani, u odnosu na ostale ispitane tehnike postavljanja. Statistčki značajno niži kvalitet marginalne adaptacije utvrđen je u grupi ispuna postavljenih uz prethodno zagrevanje i diskontinuirano polimerizovanih. Nisu dobijene statistički značajne razlike u kvalitetu marginalne adaptacije kompozitnih ispuna postavljenih različitim tehnikama u dentinske kavitete, uz istovetni, kontinuirani režim svetlosne polimerizacije. Nisu dobijene statistički značajne razlike u kvalitetu marginalne adaptacije između kompozitnih ispuna postavljenih istom tehnikom, uz različit režim svetlosne polimerizacije. Nisu dobijene statistički značajne razlike u vrednostima marginalne adaptacije između dva ispitana bulk-fill kompozitna sistema. Takođe, ni njihovim poređenjem sa vrednostima marginalne adaptacije kompozitnih ispuna postavljenih bulk tehnikom i polimerizovanih kontinuirano nisu dobijene statistički značajne razlike. Zaključak: Tehnika postavljanja i polimerizacije značajno utiče na kvalitet marginalne adaptacije kompozitnih ispuna u dentinskim kavitetima. Novi proizvod na trži&scaron;tu ne znači uvek i bolja svojstva materijala u pogledu kvaliteta marginalne adaptacije.</p> / <p>In contemporary restorative dentistry, dental composites become material of choice for reconstruction of lost tooth structure. In clinical practice it is noticed that positive properties of light-activated composites are compromised by polymerization shrinkage appearance during polymerization. The conversion of monomer molecules into polymer network is accompanied by stress transmitting to the adhesive bond what leads to the formation of microgap with clinical symptoms such as postoperative sensitivity, marginal discoloration, secondary caries and pulp pathology. The aim of this study was to compare the influence of different placing and light polymerization techniques on marginal adaptation of composite restorations. Material and Methods Examination of marginal adaptation of composites was done in dentin cavities, prepared on the buccal and oral surfaces of human third molars in laboratory conditions. The buccal and oral enamel was ground using model trimmer under running water to expose a flat dentin surface area dimension 4x4mm. Standardized cylindrical cavities (3 mm diameter, 3 mm deep) with all dentin margins were prepared using diamond cylindrical burs with copious water cooling of the working field. Taking into account the goal of this study, research was consisted of two parts. First part included 80 dentin cavities with composite system (Adper Single Bond Plus-Filtek Ultimate Flowable) placed using different placing techniques: bulk, incremental, preheated composite and by elimination of singular stress point-with pin. There were applied two light-activation techniques: continuous (40 seconds) and discontinuous (2 seconds of activation, followed by 10 seconds of dark interval, and then the polymerization is set continuously). Second part of this study included 20 the same manner prepared dentin cavities with bulk-fill composites (Filtek Bulk Fill Flowable i SDR) placed and continuously polymerized, according to the manufactures instructions. After polishing, the restored teeth were stored in a container with 100% relative humidity for 24 h to prevent dehydration. Evaluation of marginal adaptation was done using SEM analysis of replicas. After making impressions with low viscosity polyvinyl siloxane material (Ghenesyl, Super Light Body, Lascod, Florence, Italy), epoxy resin replicas were prepared for SEM analysis (Jeol, JSM-6460 Low Vacuum, Tokyo, Japan). The length of marginal gap was measured with ImageJ software (National Institute of Health, Bethesda, USA) and shown in percentage relative to total length of the margin composite/dentin. Results of marginal adaptation were compared according to application of different placing and polymerization techniques and also results of marginal adaptation of different composites bulk placed and continuously polymerized. Statistical differences were calculated using the non-parametric Mann-Whitney U-test. Results: With statistical significance there was better quality of marginal adaptation when composite was placed with pin in order to eliminate singular stress point and discontinuously polymerized, compared to other applied placing and polymerization techniques. Contrary, there was significantly higher percentage of marginal gap obtained when using pre-heated, discontinuous polymerized composites. Marginal adaptation of composite materials placed in dentin cavities using different techniques and same, continuously polymerization technique didn&rsquo;t show statistically different results. Marginal adaptation of composite materials placed in dentin cavities using same technique and different, continuously or discontinuously polymerization technique didn&rsquo;t show statistically different results. Marginal adaptation of two &ldquo;bulk-fill&rdquo; composite materials didn&rsquo;t show statistically different results. Also, compared to composites placed using bulk technique and polymerized continuously, their lower values of marginal adaptation didn&rsquo;t show significant difference. Conclusion: Placing and polymerization techniques have significant influence on the quality of marginal adaptation of composite restorations in dentin cavities. New product on the market doesn&rsquo;t always mean better marginal adaptation properties.</p>

Šiame darbe naudojamas Epsilon potenciastato modelis, sujungtas su Epsilon EC-2000-XP(Ver. 1.40.67_NT) programa ir kompiuteriu. Tyrimo metu naudojama trijų elektrodų celė. Darbiniu ir pagalbiniu elektrodais naudojami platinos elektrodas. Palyginamuoju naudojamas Ag/AgCl/KClsot elektrodas. Visos potencialų vertės nurodomos palyginamojo elektrodo atžvilgiu. POT sluoksnis nusodintas potenciostatiniu ir potenciodinaminiu būdu ant platinos elektrodo, keičiant eksperimento sąlygas. Potenciodinaminiai dengimo matavimai atlikti keičiant elektrodo potencialą nuo -0,1V iki 1,0V ir nuo -0,1V iki 1,2V. Dengiant Pt elektrodą buvo atliekama 10 arba 20 ciklų. Potencialo skleidimo greitis – 10, 20, 50 ir 100 mV/s. Potenciostatiniai dengimo matavimai atlikti esant pastoviam potencialui Econst 0,9V, 1,0V ir 1,2V ir dengimo laikui (tdeng) 1, 3 arba 5 minutės. Poli(o-metilanilinu) modifikuoti elektrodai gali būti naudojami askorbo rūgšties analizei tirpaluose, kurių pH 5,5. Askorbo rūgšties koncentracijų intervale nuo 0,1mM iki 1mM gaunama tiesinė oksidacijos ribinių srovių priklausomybė nuo koncentracijos, jei askorbo rūgšties matavimai atliekami potenciostatinėmis sąlygomis. Žemiausia askorbo rūgšties nustatymo riba – 0,1mM. / The Epsilon potentiometer model combined with a PC running Epsilon EC-2000-XP (Ver. 1.40.67_NT) software was used in these theses. During the research, a three-electrode cell was used. A platinum electrode was utilised as the working and auxiliary electrode. An Ag/AgCl/KClsot electrode was used as reference electrode. All values of the potentials refer to this electrode. An POT layer was deposited under potentiostatic or potentiodynamic conditions on platinum electrode by varying parameters of the experiment. Potentiodynamic polymer formation measurements were performed by alternating the electrode potential from 0.1V to 1.0V and from 0.1V to 1.2V. When modifying Pt electrode, 10 or 20 potential cycles were performed. The potential scan rate was 10, 20, 50, and 100 mV/s. Potentiostatic polymer formation measurements were performed under the constant potential Econst 0.9V, 1.0V, and 1.2V, and the time of coating (tcoating) was 1, 3 or 5 minutes. Poly (o-methylaniline) modified electrodes can be used for the analysis of ascorbic acid in solutions with pH values 5,5. Within the concentration interval of ascorbic acid between 0,1mM and 1mM, a linear dependence between oxidation limit currents and concentration was observed when ascorbic acid measurements were carried out potentiostatic conditions. The lowest sensing limit of ascorbic acid was 0,1mM.

Vienas iš šiuolaikinės polimerų chemijos uždavinių – gauti numatytos molekulinės masės ir architektūros polimerines medžiagas. Neseniai buvo sukurti nauji radikalinės polimerizacijos metodai, kurie priskiriami gyvybingajai (valdomai) polimerizacijai (GRP). Makromonomerų (MM) gyvybingoji radikalinė polimerizacija yra efektyvus būdas gauti šepetinius (cilindrinius) polimerus). Šepetiniai polimerai – tai makromolekulės, kuriose prie pagrindinės polimerinės grandinės prijungta daug šoninių mažesnės molekulinės masės polimerinių (oligomerinių) grandinių. Dėl tarp šoninių grandinių esančių erdvinės stūmos jėgų tokios makromolekulės įgauna neįprastų savybių, pvz., standumą, cilindrinę formą, didelį segmentų tankį. Pagrindinis šio darbo tikslas buvo susintetinti norimos sudėties šepetinius polielektrolitinius polimerus, sudarytus iš krūvį turinčios poli(met)akrilato pagrindinės grandinės ir šoninių polietilenoksido grandinių, ir ištirti jų savybes. Svarbiausieji šio darbo rezultatai, atspindintys jo naujumą, originalumą ir svarbą: Pirmą kartą nuodugniai ištirta metakrilo rūgšties (MAR) ir dviejų skirtingų molekulinių masių polietilenoksido metakrilatų PEOnMEMA (n = 5, 45) kopolimerizacija įprastiniu radikaliniu ir RAFT metodais. Sukurta metodika PEO makromonomerų kopolimerizacijos kinetikai tirti, užrašant 1H BMR spektrus in situ ir įvertinant likutinę monomerų koncentraciją reakcijos mišinyje bei momentinę kopolimero sudėtį iki gilių konversijų. Netiesiniu kintamųjų paklaidų metodu... [toliau žr. visą tekstą] / The main goal of this work was to synthesize polyelectrolyte brushes containing poly(ethylene oxide) side chains by living polymerization. Brush-like macromolecules are unique polymer molecules whose conformation and physical properties are controlled by steric repulsion of densely grafted side chains. Molecules can be either flexible or stiff, depending on the grafting density and the length of the side chains. Polymerization of macromonomers is one of the most useful ways to prepare brush copolymers. However, with the macromonomer method, the distribution of the spacing of the side chains cannot be entirely controlled which along with broad and multimodal molecular weight distribution makes these polymers heterogeneous. These problems were considered to be overcome with the use of controlled/living polymerization. Conventional free-radical and RAFT copolymerization of poly(ethylene oxide) substituent containing methacrylate macromonomers, PEO5MEMA and PEO45MEMA, with methacrylic acid (MAA) was studied by the use of 1H NMR spectroscopy for an analysis of residual monomers. RAFT copolymerization of PEO45MEMA and MAA enabled to synthesize comb copolymers with low composition distribution and more homogeneous distribution of PEO side chains along the mainchain. Amphiphilic non-ionic blockcopolymers poly(lauryl methacrylate) (PLMA) – P(PEOnMEMA) and amphiphilic anionic blockcopolymers PLMA – PMAA were prepared by the RAFT method, and their properties in aqueous and THF... [to full text]

The main goal of this work was to synthesize polyelectrolyte brushes containing poly(ethylene oxide) side chains by living polymerization. Brush-like macromolecules are unique polymer molecules whose conformation and physical properties are controlled by steric repulsion of densely grafted side chains. Molecules can be either flexible or stiff, depending on the grafting density and the length of the side chains. Polymerization of macromonomers is one of the most useful ways to prepare brush copolymers. However, with the macromonomer method, the distribution of the spacing of the side chains cannot be entirely controlled which along with broad and multimodal molecular weight distribution makes these polymers heterogeneous. These problems were considered to be overcome with the use of controlled/living polymerization. Conventional free-radical and RAFT copolymerization of poly(ethylene oxide) substituent containing methacrylate macromonomers, PEO5MEMA and PEO45MEMA, with methacrylic acid (MAA) was studied by the use of 1H NMR spectroscopy for an analysis of residual monomers. RAFT copolymerization of PEO45MEMA and MAA enabled to synthesize comb copolymers with low composition distribution and more homogeneous distribution of PEO side chains along the mainchain. Amphiphilic non-ionic blockcopolymers poly(lauryl methacrylate) (PLMA) – P(PEOnMEMA) and amphiphilic anionic blockcopolymers PLMA – PMAA were prepared by the RAFT method, and their properties in aqueous and THF... [to full text] / Vienas iš šiuolaikinės polimerų chemijos uždavinių – gauti numatytos molekulinės masės ir architektūros polimerines medžiagas. Neseniai buvo sukurti nauji radikalinės polimerizacijos metodai, kurie priskiriami gyvybingajai (valdomai) polimerizacijai (GRP). Makromonomerų (MM) gyvybingoji radikalinė polimerizacija yra efektyvus būdas gauti šepetinius (cilindrinius) polimerus). Šepetiniai polimerai – tai makromolekulės, kuriose prie pagrindinės polimerinės grandinės prijungta daug šoninių mažesnės molekulinės masės polimerinių (oligomerinių) grandinių. Dėl tarp šoninių grandinių esančių erdvinės stūmos jėgų tokios makromolekulės įgauna neįprastų savybių, pvz., standumą, cilindrinę formą, didelį segmentų tankį. Pagrindinis šio darbo tikslas buvo susintetinti norimos sudėties šepetinius polielektrolitinius polimerus, sudarytus iš krūvį turinčios poli(met)akrilato pagrindinės grandinės ir šoninių polietilenoksido grandinių, ir ištirti jų savybes. Svarbiausieji šio darbo rezultatai, atspindintys jo naujumą, originalumą ir svarbą: Pirmą kartą nuodugniai ištirta metakrilo rūgšties (MAR) ir dviejų skirtingų molekulinių masių polietilenoksido metakrilatų PEOnMEMA (n = 5, 45) kopolimerizacija įprastiniu radikaliniu ir RAFT metodais. Sukurta metodika PEO makromonomerų kopolimerizacijos kinetikai tirti, užrašant 1H BMR spektrus in situ ir įvertinant likutinę monomerų koncentraciją reakcijos mišinyje bei momentinę kopolimero sudėtį iki gilių konversijų. Netiesiniu kintamųjų paklaidų metodu... [toliau žr. visą tekstą]

<p>Uvođenje nanočestica u stomatolo&scaron;ke kompozitne materijale predstavlja poku&scaron;aj da se odgovori univerzalnim zahtevima za kvalitetom direktnog zubnog ispuna, i da se stvori materijal koji kombinuje visoku mehaničku otpornost sa dobrim estetskim karakteristikama i zadovoljavajućim kvalitetom poliranja. Cilj sprovedene studije je bio da se ispita uticaj nanočestica, i soft-start metode svetlosne indukcije polimerizacije na mehanička i povr&scaron;inska svojstva savremenih stomatolo&scaron;kih nanokompozita, dostupnih na trži&scaron;tu. Ispitana su četiri stomatolo&scaron;ka nanostrukturisana kompozitna materijala na bazi smola i jedan univerzalni mikrohibridni kompozit, kao referentni materijal (Filtek Z250, 3M ESPE). Kori&scaron;ćena su po dva reprezentativna materijala iz dve podgrupe nanokompozita: nanopunjenih (Filtek Ultimate Body, 3M ESPE i Filtek Ultimate Translucent, 3M ESPE) i nanohibridnih kompozita (Filtek Z550, 3M ESPE i Tetric EvoCeram, Ivoclar Vivadent - TEC). Uzorci su polimerizovani nakon svetlosne aktivacije polimerizacije, uz kori&scaron;ćenje dva svetlosna režima: konvencionalnog i soft start režima. Pritisna i zatezna čvrstoća (dobijena poprečnim sabijanjem valjka, engl. diametral tensile strength) testirane su na Univerzalnoj ma&scaron;ini, kidalici. Tvrdoća uzoraka merena je testom za određivanje tvrdoće po Vickersu. Povr&scaron;inska tekstura i parametri hrapavosti određeni su skeniranjem povr&scaron;ine mikroskopom atomskih sila. Uop&scaron;teno, TEC je pokazao najniže vrednosti pritisne i zatezne čvrstoće, i tvrdoće, i statistićki je značajno bio slabiji od drugih testiranih materijala kroz sve mehaničke testove. Suprotno, TEC je imao najniže vrednosti parametara hrapavosti među testiranim materijalima. Spoj prepolimerizovanog punioca i polimerne baze u ovom materijalu pokazao se kao njegova slaba tačka. Navedeni materijal je iz tog razloga pokazao značajno slabiju otpornost od ostalih na razvijene napone izazvane dejstvom mehaničkih sila. Čestice nanodimenzija u sastavu stomatolo&scaron;kih polimernih kompozita, samostalno, nisu imale značajan uticaj na pobolj&scaron;anje mehaničkih i povr&scaron;inskih svojstava testiranih kompozita. Zaključeno je i da se procentualna zastupljenost neorganskih čestica u polimernoj bazi ne može smatrati apsolutnim kriterijumom kvaliteta kompozita, u pogledu njihovih mehaničkih svojstava. Samo srodni materijali, izrađeni istim tehnolo&scaron;kim postupkom, koji imaju veoma sličan ili isti hemijski sastav, pokazali su se kao mehanički superiorniji ukoliko su sadržali veći procenat neorganske komponente u svom sastavu. Nano prefiks u nazivu klase materijala ne garantuje sigurnu prednost stomatolo&scaron;kih nanokompozita nad univerzalnim mikrohibridnim kompozitima.</p> / <p>The introduction of nanoparticles in dental composite materials was an attempt to respond to the universal quality requirements for a direct dental restoration, and to create a material that meets the needs of high mechanical resistance, good aesthetic characteristics and surface properties of tooth restoratives. The aim of this study was to investigate the effect of nanoparticles in materials composition, and the soft start photoactivation method on the mechanical and surface properties of contemporary dental nanocomposites, available in the market. Four dental resin based nanostructured composites were tested along with a universal microhybrid one, as reference material (Filtek Z250, 3M ESPE). Two representative materials from the two classification subgroups were tested, nanofilled (Filtek Ultimate Body, 3M ESPE and Filtek Ultimate Translucent, 3M ESPE) and nanohybrid composites (Filtek Z550, 3M ESPE and Tetric EvoCeram, Ivoclar Vivadent, TEC). Polymerization of the samples was light activated using two light modes: conventional and soft start. Compressive and diametral tensile strength were tested on the Universal testing machine. The Vickers hardness was also determined. Surface texture and roughness parameters were examined by atomic force microscopy. Generally, TEC showed the lowest values of compression, tensile strength and hardness, and was statistically different from the other tested materials throughout all mechanical tests. In contrast, TEC had the lowest values of roughness parameters among the tested materials. In this material, contact zone of prepolimeryzed filler and polymer matrix appeared to be a weak point. For this reason, this material showed significantly lower resistance than the others on mechanically developed stresses. Nanosized particles within the dental polymer composites, individually, did not have a significant influence on improving the mechanical and surface properties of tested composites. It is concluded that the inorganic volume fraction in composites cannot be considered as an absolute criterion of their quality, regarding their mechanical properties. Only similar materials, made using the same technological process, which have very similar or the same chemical composition, and similar technological method of synthesis and optimization of organic and inorganic components, showed improved mechanical strength, if they contained a higher percentage of inorganic components in their composition. Nano prefix in the name of material&rsquo;s class does not guarantee the pure advantage of dental nanocomposites in comparison with the universal microhybrid composites.</p>

<p style="text-align: justify;">U ovom radu sintetisani su hidrogelovi na osnovu akrilamida i akrilne kiseline, radikalnom polimerizacijom, primenom konvencionalne i mikrotalasne metode sinteze. Varirani su početni odnosi monomera i udeo umreživača, u cilju ispitivanja uticaja sastava reakcione sme&scaron;e na svojstva dobijenih hidrogelova. Optimizovani su uslovi sinteze u mikrotalasnom polju kao brže, jednostavnije i ekonomičnije metode. U cilju uspostavljanja korelacije između mehanizma sinteze, strukture i svojstava dobijenih hidrogelova, primenom relevantnih metoda karakterizacije, upoređena su apsorpciona, reolo&scaron;ka, toplotna i strukturna svojstva hidrogelova dobijenih dvema metodama.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Ustanovljeno je da se mikrotalasnom metodom sinteze na brži i jednostavniji način uz smanjen utro&scaron;ak vremena i energije dobijaju hidrogelovi konkurentni onima koji se dobijaju konvencionalnim zagrevanjem u vodenom rastvoru. Drugi deo doktorata obuhvata sintezu hidrofilnih polimernih mreža na osnovu natrijum karboksimetilceluloze (NaCMC) i karboksilnih kiselina, od kojih je jedna serija sintetisana prožimanjem linearnim kopolimerima akrilamida i akrilne kiseline u cilju povećanja potencijala primene u floku-lacione svrhe. Rezultati ispitivanja svojstava bubrenja, strukturnih toplotnih i flokulacionih svojstava pokazali su međusobno slaganje. Dobijeni rezultati pokazali su da od primenjenih karboksilnih kiselina, linunska kiselina u udelu od 15% u odnosu na masu NaCMC daje hidrogelove najboljih svojstava. Kombinacijom ove mreže sa kopolimerom akrilamida i akrilne kiseline u masenom odnosu 10/90, stvara se teorijska platforma za dobijanja flokulanta koji bi mogao da pokaže visoku efikasnost u preči&scaron;ćavanju vode u kojoj dominiraju pozitivno naelektrisane čestice, pravilnim izborom parametara flokulacije.</p> / <p>In this paper, hydrogels based on acrylamide and acrylic acid were synthesized using conventional and microwave synthetic methods via free-radical polymerization. The initial monomers ratio and amount of crosslinking agent were varied in order to investigate the effect of the composition of the reaction mixture on the properties of the obtained hydrogels. The conditions of synthesis in the microwave field as faster simpler and more economical method have been optimized. In order to establish a correlation between the mechanism of synthesis, structure and properties of the obtained hydrogels using the relevant methods of characterization, the absorption, rheological, thermal and structural properties of the hydrogels obtained by the two methods were compared. It has been found that the microwave synthesis is a faster and simpler method, which enables reduced consumption of time and energy and produces hydrogels competitive to those ones obtained by conventional heating in aqueous solution. The second part of the thesis includes the synthesis of hydrophilic polymer networks based on sodium carboxymethylcellulose (NaCMC) and carboxylic acids, whereby one series is synthesized by interpenetration of the network using the linear acrylamide and acrylic acid copolymers in order to increase the potential application of hydrogels for flocculation purposes. The results of measurements of swelling, structural, thermal and flocculation properites have shown mutual agreement. The obtained results have shown that among applied carboxylic acids, citric acid in the amount of 15% per mass of NaCMC, has given the hydrogels with the best properties. The Combination of this network with a copolymer of acrylamide and acrylic acid in a mass ratio of 10/90 has created a theoretical platform for the production of flocculant which could show high efficacy in purifying of water dominated by positively charged particles.</p>