Dissertations / Theses on the topic 'Organoclay'
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Sontikaew, Somchoke. "PET/organoclay nanocomposites." Thesis, Brunel University, 2008. http://bura.brunel.ac.uk/handle/2438/3280.
Full textLowe, David James. "Natural rubber/organoclay nanocomposites." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/2971.
Full textIsik, Isil. "Impact Modified Polyamide-organoclay Nanocomposites." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608353/index.pdf.
Full text15A, 25A and 30B) on morphology, thermal, mechanical and dynamic mechanical properties of polyamide-6 are investigated. XRD patterns show that the interlayer spacing for Cloisite®
15A remained unchanged
however it increased for the organoclays Cloisite®
25A and Cloisite®
30B in both polyamide-6/organoclay binary nanocomposites and in polyamide-6/organoclay/impact modifier ternary systems. TEM analyses indicate that exfoliated-intercalated nanocomposites are formed. Sizes of elastomeric domains in nanocomposites are larger than the domains in their corresponding blends. The MFI results show that incorporation of elastomer reduces the MFI, due to the formation of graft copolymer. Both storage and loss moduli and complex viscosity of polyamide-6 increase with organoclay addition. In DMA measurements, in rubbery region, all nanocomposites show higher storage modulus than the unfilled counterparts. In general, the organoclays increase tensile and flexural strength, Young&
#8217
s and flexural modulus and elongation at break, but decrease the impact strength, on the contrary, the addition of elastomer has the opposite effect. Generally, Cloisite®
15A containing ternary nanocomposites have higher tensile, flexural and impact strength and Young&
#8217
s and flexural modulus than the ternary nanocomposites prepared with Cloisite®
25A and Cloisite®
30B. In general, nanocomposites processed by adding all the ingredients simultaneously give higher tensile and flexural strength and modulus than the nanocomposites produced by other mixing sequences.
Yao, Kejian. "Higher performance polyurethane-organoclay nanocomposites." Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/7795.
Full textMert, Miray. "Impact Modified Nylon 66-organoclay Nanocomposites." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608112/index.pdf.
Full textAlyamac, Elif. "Impact Modified Poly(ethylene Terephthalate)-organoclay Nanocomposites." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605092/index.pdf.
Full texts modulus and reasonable elongation at break was selected owing to its balanced mechanical properties. Thereafter, by using 5 wt. % terpolymer content, the effects of organically modified clay concentration and addition order of the components on ternary nanocomposites were systematically investigated. Mechanical testing revealed that different addition orders of the materials significantly affected mechanical properties. Among the investigated addition orders, the best sequence of component addition (PI-C) was the one in which poly(ethylene terephthalate) was first compounded with E-MA-GMA. Later, this mixture was compounded with the organoclay in the subsequent run. Young'
s modulus of not extruded pure PET increased by 67% in samples with 5 wt. % E-MA-GMA plus 5 wt. % clay loading. The highest percent elongation at break was obtained as 300%, for the addition order of PI-C, with 1 wt. % clay content, which is nearly 50 fold higher than that obtained for pure PET. In X-ray diffraction analysis, extensive layer separation associated with delamination of the original clay structure occurred in PI-C and CI-P sequences with both 1 and 3 wt. % clay contents. X-ray diffraction patterns showed that, at these conditions exfoliated structures resulted as indicated by the disappearence of any peaks due to the diffraction within the consecutive clay layers.
Yayla, Saniye. "Production And Characterization Of Polypropylene/organoclay Nanocomposites." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12608485/index.pdf.
Full text30B, Cloisite®
15A, and Cloisite®
25A were used as organoclay. iv In order to determine the optimum amount of compatibilizer, PP/compatibilizer blends were produced with different compositions. The content of compatibilizer was determined as 5 wt % based on the mechanical tests. Then, ternary nanocomposites were prepared with 5 wt % compatibilizer and 2 wt % organoclay contents. In addition, neat PP and PP/organoclay composites were prepared in order to make comparison. After that, the samples were characterized. According to the XRD analysis, the highest increase in the interlayer spacings of organoclays were observed in the PP/E-MA-GMA/Cloisite®
15A (23%) and PP/E-MA-GMA/ Cloisite®
25A (88.3%) ternary systems. SEM micrograms revealed that compatibilizer E-MA-GMA is the most compatible elastomer with PP. Thus, it was decided to investigate the effect of mixing order on the properties of these nanocomposites with E-MA-GMA. DSC analysis showed that the melting behavior of the nanocomposites does not change significantly with the presence of organoclay and compatibilizer. In addition, compatibilizers and organoclays have no significant nucleation activity in PP. The systems PP/E-MA-GMA/Cloisite®
15A and PP/E-MA-GMA/Cloisite®
25A have the highest improvements according to the results of mechanical tests. The results of mechanical tests showed that the mixing sequence (PEC), in which PP, organoclay and compatibilizer were compounded simultaneously in the first extrusion run, is the best sequence.
Whilton, Nicola Tracey. "Routes to novel nano-structured organoclay composites." Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390226.
Full textDelozier, Donavon Mark. "Preparation and characterization of polyimide/organoclay nanocomposites." W&M ScholarWorks, 2002. https://scholarworks.wm.edu/etd/1539623403.
Full textInam, Deniz. "Organoclay Preparation For Anionic Contaminant Removal From Water." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606674/index.pdf.
Full text#8216
organoclay&
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, can be used to remove hydrophobic organic and anionic contaminants from polluted water. Among the anionic contaminants, oxyanions such as nitrate, chromate are detrimental to human life and environment even at µ
g/L- mg/L levels. Application of organoclays for their removal from polluted water appears as one of the practical and rather cheap solution. In this study, a local clay from Ankara-Kalecik (Hanç
ili Bentonite) was modified by hexadecyltrimethylammonium bromide (HDTMA-Br) to a level of twice of its cation exchange capacity. This process alters the negatively charged surface of the clay into a positively charged one, providing sites for the removal of anionic contaminants. In this study, the degree of HDTMA+ uptake by the clay within a period of eight hours is found to be 97% of the initial amount added. In desorption studies it was revealed that only about 1% of the sorbed HTDMA+ was leached in a seven days of water-organoclay interaction revealing a rather stable organoclay structure in aqeous media. Sorption experiments with nitrate, borate, and chromate solutions were performed in order to determine the anion sorption capacity of the organoclays prepared. It turns out that while untreated clay has insignificant capacity, the modified clay can remove considerable amount of nitrate and chromate ions from aqeous solutions. While the nitrate sorption was increased about eleven fold, change in chromate sorption was reached to a level of twenty fold compared to that of the untreated clay. Sorption data for nitrate and chromate are both well described by the Langmuir isotherms. No significant change was observed in case of borate-organoclay interaction. Desorption of nitrate and chromate ions from organoclay surface were also investigated. Sorption of these oxyanions were found to be almost irreversible in aqeous media. The results imply that a properly prepared organoclay can be used for the removal of oxyanions, such as nitrate and chromate from polluted water systems.
Martin, Jessica Elizabeth. "Synthesis and characterization of novel organoclay-based materials." Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546184.
Full textPatil, Avinash J. "Novel organoclay based self-assembled bio-inorganic nanomaterials." Thesis, University of Bristol, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409001.
Full textZha, Weibin. "ORGANOCLAY NANOCOMPOSITES BASED ON VINYLPYRIDINE-CONTAINING BLOCK COPOLYMERS." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1163105468.
Full textHuang, Gang. "CHARACTERIZATION AND PROPERTY STUDIES OF CYANATE ESTER/ORGANOCLAY NOCOMPOSITES." MSSTATE, 2006. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07072006-162122/.
Full textSukhummek, Boonnak. "Polyurethane/poly(ethyl methacrylate) interpenetrating polymer network organoclay nanocomposites." Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/14170.
Full textIslam, Sonia. "Investigation of oil adsorption capacity of granular organoclay media and the kinetics of oil removal from oil-in-water emulsions." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4979.
Full textQin, Wei. "Effect of organoclay reinforcement on pyrolytic-lignin-based carbon fibres." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30310.
Full textMcLauchlin, Andrew R. "Development of a novel organoclay for poly(lactic acid) nanocomposites." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/10298.
Full textMotedayen, Ali Akbar. "Novel stratified self-assembled Polyehtylene-Organoclay films for food packaging." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT156.
Full textInspired by the traditional Layer-by-Layer (LbL) assembly technique, this PhD study demonstrates the first effort to develop a novel methodology for multilayer self-assembly on the basis of hydrophobic interactions and further physical adsorption to fabricate stratified Polyethylene(LLDPE)-organoclay(OMMT) nano-enabled composite film. In contrary to the electrostatic LbL technique, here, the multilayer films were synthesized by starting from an uncharged apolar polymer substrate and successively depositing apolar organoclay and uncharged apolar PE layers with subsequent repeating depositions. The alternate variation of contact angle (85° average for organoclay and 107° for PE layers) confirmed the profilometry and the scanning electron microscopy results as well as the linear growth pattern, i.e. the successful highly stratified assembly of repetitive bilayers comprised of 450 nm organoclays and 2.25 µm PE layers. Further characterization tests were performed to evaluate the effect of the main identified process parameters (concentration, temperature, rinsing and drying steps, and solvent type) variation on the formation and thickness growth of the films. As a consequence, the high dependence of the self-assembly’s growth to the tested process parameters was showed by the obtained experimental results. The barrier properties of the multilayer films were also evaluated by characterizing the Water vapour, Oxygen (O2), and Carbon dioxide (CO2) permeability as well as the water vapour sorption. A 5-bilayer (OMMT/PE) coating (∼14 µm thick) reduced the O2 permeability of a 160 µm-thick PE film by 84.4% and the CO2 permeability by 70%, while the WVP was reduced by 45%. These permeability reductions obtained by only 2.4 v/v % of nanoclay addition level were found to be significantly greater compared to the reduction values reported in the literature for prepared blend PE/organoclay nanocomposites. This knowledge can be used in the establishment of an approach to produce stratified micro/nanostructures with tailored barrier properties for food packaging application
Alipour, A. "Characterization of Elastomer Nanocomposite Blends Based on NR/EPDM/Organoclay." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35610.
Full textTuna, Basak. "Chain Extension of Polyamide-6 & Polyamide-6/Organoclay Nanocomposites. Control of thermal degradation of polyamide-6/organoclay nanocomposites during extrusion using a novel chain extender." Thesis, University of Bradford, 2016. http://hdl.handle.net/10454/14583.
Full textBrown, Loren C. "Immobilization of Heavy Metals in Contaminated Soils and Sludge Using Organoclay." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/etd/1178.
Full textAddy, Mary Akuyea. "Modified Organoclay Containing Chelating Ligand for Adsorption of Heavy Metals in Solution." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1372.
Full textAkhtar, Mohamed U. "Towards controlled release of a natural mosquito repellent from polymer matrices." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/46236.
Full textDissertation (MSc)--University of Pretoria, 2014.
tm2015
Chemical Engineering
MSc
Unrestricted
Yilmaz, Sule Seda. "Preparation And Characterization Of Organoclay-polypropylene Nanocomposites With Maleic Anhydride Grafted Polypropylene Compatibilizer." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613291/index.pdf.
Full textMoplen&rdquo
EP300L which is a heterophase copolymer. Polymer blends and nanocomposites were prepared by melt compounding method in a twin screw extruder. Nanofil®
5 (N5) and Nanofil®
8(N8) were used as the organoclays, and maleic anhydride grafted polypropylene (M) was used as the compatibilizer. The effects of additive concentrations and types of organoclays on the morphology, mechanical and thermal properties were investigated. Organoclay loading over 2 wt% prevented the intercalation mechanism resulting in large aggregates of clay, thus the material properties became poor even in the presence of compatibilizer. Compatibilizer addition improved the intercalation ability of the polymer, however a substantial increase in mechanical properties was not obtained up to 6 wt % loading of the compatibilizer. XRD analysis revealed that intercalated structures were formed with the addition of compatibilizer and organoclay. The nanocomposites that were prepared with N5 type organoclay showed delaminated structures at 6 wt % compatibilizer loading. v Nanofill ®
5 exhibited the highest improvements in mechanical properties, since the degree of organoclay dispersion was better in Nanofill ®
5 containing nanocomposites in comparison to Nanofill ®
8 containing ones. The DSC analysis indicated a insignificant reduction in the melting temperature of the ternary nanocomposites.
Wingert, Maxwell. "Carbon dioxide foaming and High-pressure rheology of polystyrene and polystyrene/organoclay nanocomposites." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1167770881.
Full textFurrow, Brendan Eugene. "Analysis of hydrocarbon removal methods for the management of oilfield brines and produced waters." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2611.
Full textPeng, Shirley. "Synthesis and Characterization of Crosslinked Polyurethane-Clay Nanocomposites." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427813762.
Full textKeyfoglu, Ali Emrah. "Effects Of Chain Extension And Branching On The Properties Of Recycled Poly(ethylene Terephthalate)-organoclay Nanocomposites." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605020/index.pdf.
Full text#506
to about 28-34 &
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after processing with polymer indicating an intercalated structure. PMDA, MA and organoclay content as well as the screw speed did not have a recognizable effect on interlayer distance. In the first extrusion step, nanocomposites containing 3% organoclay content gave significant increase in Young&rsquo
s modulus and decrease in elongation to break values indicating good interfacial adhesion. After the addition of chain extenders, it was observed that both MA and PMDA gave rise to improved mechanical properties of the nanocomposite owing to the branching and chain extending effects that increase the molecular weight. However, PMDA gave better mechanical properties at lower content which makes it a more effective chain extender. DSC analysis showed that MA was more effective in increasing the glass transition temperature and melting temperature in comparison to PMDA.
Ozkoc, Guralp. "Abs/polyamide-6 Blends, Their Short Glass Fiber Composites And Organoclay Based Nanocomposites: Processing And Characterization." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608266/index.pdf.
Full textNeitsch, Susan Lynn. "Adsorption and desorption of atrazine on a melamine-based soil amendment." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/567.
Full textBedin, Sidmara 1988. "Preparação e caracterização de argila oganofílica para adsorção de BTX." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266118.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-24T22:59:54Z (GMT). No. of bitstreams: 1 Bedin_Sidmara_M.pdf: 4205652 bytes, checksum: d622e46268c9acb2352410201461233c (MD5) Previous issue date: 2014
Resumo: Diariamente, uma grande quantidade de fluxos de água sofre contaminação por compostos orgânicos como, por exemplo, o benzeno, tolueno e xileno (BTX), os quais são compostos tóxicos e nocivos ao meio ambiente e aos seres humanos. Sendo assim, o estudo de técnicas de remoção e tratamento desses poluentes vem se tornando tema de muitas pesquisas. A adsorção tem se mostrado uma técnica bastante eficiente, pois atende aos limites da legislação, apresenta baixo consumo energético e custo de processo, ainda mais quando se faz uso de um adsorvente alternativo, como é o caso da argila organofílica. Nesse trabalho foi proposto avaliar a argila esmectítica sódica nacional Fluidgel, na forma natural e organofilizada, como materiais adsorventes alternativos na remoção dos compostos orgânicos BTX de soluções aquosas, em ensaios em sistema batelada e em sistema dinâmico. A argila organofílica foi preparada a partir da argila comercial e do sal quaternário de amônia HDTMA e se verificou a capacidade de troca catiônicas dos adsorventes. Foram realizadas técnicas de caracterização com a finalidade de determinar a área superficial do material, estrutura de poros, estrutura cristalina, morfologia de superfície, composição química, perda de massa e água e identificação de grupos funcionais de superfície. Testes preliminares comprovaram o caráter hidrofóbico da argila organofílica e sua afinidade por compostos orgânicos, bem como o caráter hidrofílico da argila comercial. Ensaios cinéticos de pH mostraram que o mesmo não afeta de maneira significativa o processo de adsorção. Os ensaios cinéticos de adsorção realizados em sistema batelada alcançaram o equilíbrio em 3h e apresentaram porcentagens de remoção de poluente superiores a 90%, com concentração inicial de 1,09 mmol/L. Os modelos cinéticos analisados foram o de pseudoprimeira ordem, pseudossegunda ordem e o de difusão intrapartícula, sendo que o modelo de pseudossegunda ordem melhor descreveu os dados experimentais. Para as isotermas de equilíbrios, testou-se as temperaturas de 35, 25 e 15 oC, sendo a maior capacidade de remoção com a maior temperatura, indicando que a adsorção nesse caso é de natureza endotérmica. Os modelos de isotermas avaliados foram Langmuir, Freundlich, Sips, DSL, MSAM e D-R, porém apenas o modelo de D-R descreveu de maneira satisfatória os dados experimentais. Pela análise dos parâmetros termodinâmicos, verificou-se que o processo de adsorção em estudo é espontâneo, favorecido a altas temperaturas e que possivelmente ocorre fisissorção. Devido à alta volatilidade dos compostos BTX, foi feita uma adaptação na adsorção em sistema dinâmico através de coluna de leito fixo e se realizou um ensaio cinético em leito de adsorção. A ordem de remoção dos compostos orgânicos, para ambas as argilas, foi xileno > tolueno > benzeno
Abstract: Daily a large amount of water flows suffers contamination by organic compounds as, for example, benzene, toluene and xylene (BTX), which are toxic compounds and harmful to the environment and to humans. Thus, the study of techniques for removal and treatment of these pollutants has become the subject of much research. The adsorption has proven to be a very effective technique because it meets the limits of the law, has low energy consumption and process cost, further when it makes use of an alternative adsorbent, as is the case with organoclay. In this study, it was proposed evaluate the national sodium smectite clay Fluidgel , in the natural and organophilizated form, as an alternative adsorbent material to the removal of organic compounds BTX from aqueous solutions in batch and dynamic system essays. The organoclay was prepared from the commercial clay and the quaternary ammonium salt HDTMA and it was verified the cationic exchange capacity of the adsorbents. Were performed characterization techniques in order to determine the surface area of the material, pore structure, crystal structure, surface morphology, chemical composition, mass and water loss and identification of surface functional groups. Preliminary tests confirmed the hydrophobic character of the organoclay and their affinity for organic compounds and the hydrophilic character of the commercial clay. pH kinetic experiments showed that the same does not affect significantly the adsorption process. Kinetic assays of adsorption performed in batch system reached equilibrium in 3 hours and showed pollutant removal percentages greater than 90%, with an initial concentration of 1.09 mmol/L. The kinetic models analyzed were the pseudo first order, pseudo second order and the intraparticle diffusion, being that the pseudo second order model best described the experimental data. For the equilibrium isotherm, was tested at temperatures of 35, 25 and 15 °C, being the largest removal capacity with the greatest temperature, indicating that the adsorption of this case is endothermic in nature. The isotherm models evaluated were Langmuir, Freundlich, Sips, DSL, MSAM and D-R, but only the D-R model described satisfactorily the experimental data. By the analysis of the thermodynamic parameters, it was found that the adsorption in study is spontaneous and favorable at high temperatures and that possibly occurs physisorption. Due to the high volatility of BTX compounds, it was made an adaptation to dynamic adsorption system through fixed bed column and a kinetic assay was carried out in adsorption bed. The order of removal of organic compounds for both clays was xylene > toluene > benzene
Mestrado
Engenharia Química
Mestra em Engenharia Química
Battirola, Liliane Cristina. "Estruturas grafitizadas e nanocompósitos a base de Poli(imida)/argila organomodificada: síntese, caracterizações e aplicações." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-09042013-090507/.
Full textIn this work, Poli(imide)/clay (PI/clay) nanocomposite membranes were synthesized by employing a two-steps method using organically modified montmorillonite clay (O-MMT) with different amounts of O-MMT loading (3.3, 5.3 and 8.3 wt.%). Fourier transform infrared spectroscopy (FTIR), X-ray power diffraction (XRD), thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS), optical microscopy (OM), scanning electron microscope (SEM) and transmission electron microscopy (TEM) measurements, confirmed the formation of pure PI and intercalated-nanocomposite structures. The results revealed parallel clay layers with interlamellar PI and some organoclay partially exfoliated. In addition, the polyelectrolyte membranes of PI and PI/O-MMT (3.3 wt.%) showed that the ionic conductivity were 2- and 1-fold, respectively, higher than that of commercial membrane (Tokuyama®, 0.014 S cm-1), in alkaline fuel cells (AFC) at 60 °C. Despite the fact that the membranes of pure PI and PI/O-MMT demonstrated a good degree of ionic conductivity, rapid fuel cell performance deactivation occurred for the temperature higher than 75 °C. Furthermore, the lack of prepared polyelectrolyte ionic groups, led us to consider alternative synthesis of PI/clay nanocomposite membranes. Thus, the performance for second polyelectrolyte was superior when compared to pure PI, PI/O-MMT and commercial Tokuyama® membranes at same conditions. Moreover, the samples were also surface carbonized by thermal treatment. Combining FTIR, XRD, TG, XPS and electron paramagnetic resonance (ESR) analysis, the results suggested that graphitized nanostructures formation occurred mainly on the surface, maintaining the PI bulk structure. Therefore, graphitized PI/clay membranes may act as one promising way for enhancing both membrane electrode assembly in alkaline fuel cells and gas separation or catalysis.
Silva, Wagner Claudio da. "Argila organofílica como agente microbiano para tintas." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-04072012-171310/.
Full textQuaternary ammonium compounds are widely used as antiseptic agents, disinfectants, detergents and preservatives. In addition, quaternary ammonium compounds are often used as algaecides, and dodecyl dimethyl benzyl ammonium chloride (benzalkonium chloride) is the most effective against these microorganisms. However benzalkonium chloride is not used as surface algaecide compound due its high hydrophilic, bring on high leaching of this compound when the surface is exposed to high humidity and severe weather from tropical climate. Currently, compounds such as diuron and s-triazine are used as microbial agent, considered low leaching. However diuron and s-triazine were detected in coastal regions in high levels concentration showing the leaching of these biocides when used in antifouling paints in ships. Considering these, it can be observed the necessity to develop a new algaecide to overcome the failings of leaching of the compounds used nowadays. Material as organoclay is an excellent alternative because they are highly hydrophobic. Therefore in this work was synthesized a new nanomaterial using benzalkonium chloride, which was applied in a house paint formulation. The material was characterized by the techniques of X-ray diffraction and thermogravimetric analysis. A film coating was placed in a leaching chamber, simulating the action of rain. After leaching the coating film was applied to microbiological tests to check if the surface still had microbial protection against the following algae species: Phormidium cebenense, Trentepohlia odorata, Chlorella sp and Scenedesmus quadricauda; placed in a pool of algae. It was possible to determine the structure and quantify the amount of benzalkonium chloride in the material through X-ray Diffraction and Thermogravimetric analysis, respectively. The biocide capabilities as well as the resistance to weathering of coating with the material were analyzed by microbiological and leaching test, respectively. The new compound developed in this study has a high potential to be used as microbial agent in paints.
Lins, Pedro Garcia. "Obtenção e caracterização de nanocompósitos de PS / argila esmectítica." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-08122011-094430/.
Full textIn this work, the obtention of organoclays and nanocomposites of polystyrene (PS) using these modified clays was studied. In a first part Brazilian smectites clays were modified to be used in clay containing polymer nanocomposites. Several quaternary ammonium salts and experimental methods to modify the clays were used. In particular four parameters were evaluated: the type of ammonium salt, the particle clay size, the temperature and time used during the process of modification. The samples obtained were characterized by X-ray diffraction (XRD), Foster swelling test and differential thermal analysis (DTG). The results indicated that the most two important parameters in the process of modification are the time and the temperature used. In a second part nanocomposites of PS with organoclays (one obtained in the first part, and commercial clay, named cloisite 20A) were obtained by melt intercalation method using a twin screw extruder and an internal mixer. The clays were incorporated to the polymer as a fine dried powder and as a suspension of ethanol. Nanocomposites were molded by compression and injection. The injection conditions were modified to evaluate their influence on the morphology of the samples. The nanocomposites samples were characterized by XRD, transmission electronic microscopy (TEM), DTG and mechanical tests. Small amplitude oscillatory shear (SAOS) and time sweep tests were carried out. Nanocomposites of intercalated structure were obtained. The ones obtained using the internal mixer were shown to present a finer microstructure. The experimental results revealed that the residence time was showed the most important parameter in obtention of nanocomposites.
Wiles, Melinda Christine. "Chemical and biological methods for the analysis and remediation of environmental contaminants frequently identified at Superfund sites." Texas A&M University, 2004. http://hdl.handle.net/1969.1/1244.
Full textZhang, Wenchao. "Processing and Permeability of Polyimide-Clay Nanocomposite Membranes." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1237222011.
Full textDe, Oliveira Tiago. "Absorption de produits pharmaceutiques par les organoclays : des matériaux polyvalents pour des applications environnementales." Thesis, Orléans, 2019. http://www.theses.fr/2019ORLE3001.
Full textAdsorption represents an easy, simple and low-cost way to remove both organic and inorganic pollutants in water. Clay minerals are well known for their outstanding adsorption properties for numerous products. The chemical modification of its surface through the intercalation of surfactants for the preparation of organoclays considerably improves the adsorption properties, in particular for hydrophobic organic compounds such as pharmaceutical products (PPs) which are more and more commonly found in sewage and surface water. In the present contribution, the adsorption PPs with different therapeutic actions and varied physicochemical properties onto clay mineral and organoclay derivatives prepared with different surfactants (cationic and nonionic) has been studied with a particular understanding of the interactional mechanisms of PP with the adsorbents in order to (i) evaluate the stability of materials for an application in purifying context and (ii) to apprehend the role of the mineral phases in the fate of organic micropollutants in the natural environment. The experimental data obtained by a set of complementary techniques reveal that organoclays prepared with nonionic surfactants show a versatility for numerous PPs while the hydrophobic environment generated by the grafting of surfactants with alkyl-chains particularly enhances the adsorption of the organic compounds. The study confirmed the efficiency and the promising remediation behavior of organoclays for wastewater treatment
Acosta, Otero Erick J. "Synthesis and application of dendrimers on solid supports." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/1576.
Full textCengiz, Filiz. "Preparation And Characterization Of Recycled Polypropylene Based Nanocomposites." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609873/index.pdf.
Full text15A, Cloisite®
25A and Cloisite®
30B were used as organoclays, and ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) and maleic anhydride grafted polypropylene (PP-MAH) were used as compatibilizers. The effects of additive concentrations, types of organoclays and compatibilizers, processing conditions, and the compatibilizer to organoclay ratio on the morphology and mechanical, thermal and flow properties were investigated. Organoclay loading over 2 wt% prevented the intercalation mechanism and material properties, even in the presence of compatibilizer, as a consequence of large clay agglomerate formation. E-MA-GMA compatibilizer improved the intercalation ability of the polymer
however a substantial increase in mechanical properties was not obtained. PP-MAH is found to be a better compatibilizer. Processing conditions significantly affected both mechanical properties and morphology. When the processing temperature was decreased and screw speed was increased simultaneously, tensile and impact properties were improved owing to enhanced shear and dispersive forces. TEM analysis revealed that intercalated and delaminated structures were formed with the addition of PP-MAH compatibilizer. In addition to that, as the ratio of PP-MAH to organoclay was increased, more effective dispersion of organoclay was observed and hence resultant improvements in both tensile and impact properties were greater at compatibilizer to organoclay ratio of three. Cloisite®
15A exhibited the highest improvements in mechanical properties, although the degree of organoclay dispersion was better for Cloisite®
25A and particularly for Cloisite®
30B. Melt flow index values were lower compared to pure recycled polypropylene in the presence of organoclay and compatibilizers. DSC analysis indicated no significant change in the melting behavior of the matrix materials.
Yeniova, Canan Esma. "Impact Modified Polystyrene Based Nanocomposites." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610306/index.pdf.
Full text30B, 25A and 15A) were used as fillers. Nanocomposite preparation was performed in a co-rotating twin screw extruder. Initially elastomer and organoclay contents were kept at 5wt% and 1-2wt% respectively. Well dispersed silicate layers were obtained for the nanocomposite containing SEBS-g-MA and Cloisite®
25A owing to the high viscosity of SEBS-g-MA and the solubility of polystyrene end block of SEBS with PS matrix. Owing to higher hydrophobicity of Cloisite®
15A a better dispersion was expected compared to Cloisite®
25A, but, it was concluded that two long aliphatic tails of Cloisite®
15A limited the access of polymer chains to the clay surface. The desired impact strength values could not be achieved by using 5wt% elastomeric materials
therefore, it was decided to increase the SEBS-g-MA content up to 15, 20, 30 and 40wt%. With increasing elastomer content, increasing average elastomer domain size was obtained. Also, it was observed that with the addition of organoclay, the elastomeric domain size increases since the clay particles reside in the elastomer phase and at the interphase between elastomer and PS. The mechanical test results showed that the nanocomposites containing 15 and 20wt% SEBS-g-MA have the optimum average domain size that results in better impact strength values without deteriorating tensile properties.
Dike, Ali Sinan. "Nanocomposites Based On Blends Of Polystyrene." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613296/index.pdf.
Full textand Cloisite
Stofela, Sara Karoline Figueiredo 1989. "Remoção de compostos BTX em argila organofílica por adsorção em fase líquida." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266117.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: Resíduos contaminados com compostos orgânicos, sendo grande parte formados por hidrocarbonetos aromáticos, como o benzeno, tolueno e xileno, vem sendo gerados em grandes quantidades nas indústrias e em derramamentos de postos de estocagem de combustíveis. Sendo assim, surge espaço para novas pesquisas de tratamento desses efluentes, como a adsorção em argilas organofílicas. Portanto, o objetivo deste trabalho é avaliar o potencial da argila organofílica Spectrogel na adsorção dos compostos BTX. Para este estudo foram realizados teste de hidratação e expansão em meio orgânico, estudo do efeito do pH, avaliação do potencial de remoção e estudo cinético, por meio de ensaios cinéticos de adsorção monocomposto, bicompostos e tricompostos, estudo de equilíbrio, atráves de ensaios de equilíbrio monocomposto, bicompostos e tricompostos, nas temperaturas de 15, 25 e 35 oC, estudo termodinâmico, caracterização do material adsorvente antes e após os ensaios de adsorção, estudo de regeneração do adsorvente, e análise estatística do processo de adsorção. A argila apresentou uma eficiência de remoção de 95%, 89% e 96% para o benzeno, tolueno e xileno, respectivamente e mostrou que o processo é rápido com no máximo 120 min para atingir o equilíbrio. No estudo cinético, tanto o modelo pseudoprimeira-ordem, quanto o pseudossegunda ordem apresentaram boas correlações. O modelo de difusão intrapartícula e modelo de Boyd indicaram que a adsorção é controlada tanto pela difusão intrapartícula, como pela difusão externa. O estudo de equilíbrio indicou que o xileno é o contaminante com maior afinidade pelo meios adsorvente. Entre os modelos de isotermas utilizados nos ajustes dos dados experimentais, o modelo de Dubinin-Radushkevitch foi o que apresentou melhor correlação para todas as isotermas monocomposto. Para as isotermas bicompostos, o modelo de Freundlich foi o que melhor se ajustou. Os parâmetros termodinâmicos mostraram que o processo de adsorção de BTX em argila Spectrogel é espontâneo e endotérmico. A caracterização do adsorvente após a adsorção dos BTX mostrou que o mesmo é pouco poroso e possui a superfície heterogênea, evidenciando a presença dos compostos BTX e algumas mudanças estruturais no material adsorvente. Por fim, os ensaios de regeneração indicaram a regeneração do adsorvente por meio do eluente etanol
Abstract: Contaminated waste with organic compounds, being largely composed of aromatic hydrocarbons such as benzene, toluene and xylene, has being generated in large quantities in industries and spills fuel storage stations. Thus, it arises space for further research about treatment of these effluents, such as adsorption on organoclay. Therefore, the aim of this study is to evaluate the adsorption of BTX compounds into organoclay Spectrogel. For this study tests of hydration and expansion in organic media and tests of the effect of pH were conducted. Equilibrium study was also performed by tests of mono-component, bi-component and multicomponent solutions at temperatures of 15, 25 and 35 oC. The adsorbent was characterized before and after the adsorption experiments. Finally, the regeneration of the adsorbent through eluents and a statistical study of the adsorption process were also performed. The evaluation of the potential removal provided a removal efficiency of 95%, 89% and 96% for benzene, toluene and xylene, respectively and showed that the process is fast taking a maximum of 120 min to reach equilibrium. In the kinetic study, both the pseudo first order model, as well as pseudo second order model showed a good correlation. The intraparticle diffusion model and Boyd model indicated that adsorption is controlled by both intraparticle diffusion and external diffusion. The equilibrium study indicated that xylene is the most competitive contaminant by active adsorption site. Among the isotherm models used, only the Dubinin-Radushkevitch showed a good correlation for all mono-component isotherms. For bi-component isotherms, the Freundlich model showed the best fit. The thermodynamic parameters indicated that the adsorption process of BTX into clay is spontaneous and endothermic. The characterization of the study showed that the this adsorbent is porous and presents a heterogeneous surface after adsorption and the presence of BTX compounds and structural changes were observed in the adsorbent material after process. The dessorption tests indicated a possible regeneration of the adsorbent using ethanol as eluent.z
Mestrado
Desenvolvimento de Processos Químicos
Mestra em Engenharia Química
Zhu, Honggang. "Development of epoxy-organoclay nanocomposite as high performance coating and as matrix material of durable GFRP composite for civil engineering applications /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202009%20ZHU.
Full textIsik, Fatma. "Nanocomposites Based On Blends Of Polyethylene." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606338/index.pdf.
Full textas organoclay Cloisite&
#61666
15A, Cloisite&
#61666
25A and Cloisite&
#61666
30B were used. All samples were prepared by a co-rotating twin screw extruder, followed by injection molding. Before producing the ternary nanocomposites, in order to determine the optimum amount of the organoclay and compatibilizer, binary mixtures of LDPE/organoclay and LDPE/compatibilizer blends with different compositions were prepared. Based on the results of the mechanical tests, compatibilizer and organoclay contents were determined as 5 wt. % and 2 wt % respectively. After that, ternary nanocomposites were prepared with each compatibilizer/organoclay system and characterization of these nanocomposites was performed. Among the investigated addition orders, mechanical test results showed that the best sequence of component addition was (PCoC), in which LDPE, compatibilizer and organoclay were simultaneously compounded in the first run of the extrusion. Considering the ternary nanocomposites, compositions of LDPE/E-MA-GMA/15A, LDPE/E-GMA/15A and LDPE/E-nBA-MAH/30B showed the highest improvement in mechanical properties. According to the DSC analysis, addition of organoclay and compatibilizer does not influence the melting behavior of the compositions and both compatibilizers and organoclay types have no nucleation activity in LDPE. In the X-Ray analysis, the highest increase of the basal spacing for ternary nanocomposites obtained for LDPE/E-BA-MAH/organoclay nanocomposites. This increase was 83 %, 198 %, and 206 % for samples containing 15A, 25A and 30B respectively.
Tolga, Asli. "Nanocomposites Based On Recycled Poly(ethylene Terepthalate)." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606309/index.pdf.
Full textBildiren, Mert. "Preparation Of Clay-polymer Nanocomposite For The Retardation Of Waste Water Infiltration In Landfill Sites." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608872/index.pdf.
Full textili (Kalecik-Ankara) bentonite deposit which belongs to the Hancili Formation of Early Pliocene age. B3 is a standard Wyoming (SWy-1) white bentonite and belongs to the Newcastle formation of Cretaceous age. Their cation exchange and swelling capacity values were determined and the values increase from B1, B2 to B3. In order to produce clay-polymer nanocomposites, firstly organoclays were produced in bentonite samples. Claypolymer nanocomposite production was achieved by in situ intercalative polymerization successfully with intercalation and partly exfoliation of clay minerals with polyacrylamide (PAM). The samples of sand (S1), sand+bentonite (S2) and sand+nanocomposite (S3) mixtures were prepared and their permeability was determined. As a result of these values, the permeability of samples decrease from S1, S2 to S3. The results imply that the permeability of sample decreases as the claypolymer nanocomposite content increases resulting in a retardation of water penetration throughout the sample. The product has a potential to be used as a retardant for waste water infiltration in landfill sites.
Terrin, Marina Martins. "Efeito da concentração de argila nas propriedades termomecânicas de uma resina dentária modelo." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-05062014-160728/.
Full textIn spite of the developments that led to the use of dental composites, there are still some shortcomings that limit their use. Inadequate resistance due to the mastigatory wearing is often cited as an issue in resins, which is partially responsible for reducing its lifetime. Wearing out of the material occurs by the loss or degradation of the organic matrix, thus allowing the inorganic matrix to become exposed and consequently leading to its loss. Therefore, the present work has as main goal the evaluation of the effect of different organoclay filler content in the properties of a experimental dental resin. For such, the clay was first purified and then underwent through cationic exchange, following preparation of the resins and later addition of the organoclay obtained and preparing the specimens. The, the resins were evaluated by techniques such as DMA, TGA, PCA, DRX and swelling tests to observe water sorption. By FTIR and PCA it was possible to follow the reaction kinectics of the prepared resins, thus obtaining the degree of convertion and polymerization rate, allowing to observe that the higher the organoclay loadings the lower was both the polymerization rate and the degree of convertion. TGA allowed us to observe two peaks on the second process of thermal degradation on the sample with no clay, thus indicating a non-homogeneous polymerization; and with higher clay loadings the double peaks become one single peak. DMA showed a slight increase of Tg and also an increase in E\' and E\", indicating a reinforcement of the obtained composites. DRX showed no exfoliation of the polymer, thus forming either a conventional composite or maybe a interlacated composite with no expansion of the interlamelar space. Swelling tests showed that the higher the amount of organoclay added the higher was the amount of water absorbed by the specimens.
Anita, Leovac-Maćerak. "Adsorpciono ponašanje odabranih organskih ksenobiotika na sorbentima relevantnim za tretman voda." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2017. https://www.cris.uns.ac.rs/record.jsf?recordId=102596&source=NDLTD&language=en.
Full textThe focus of this doctoral thesis was the study of the sorption behavior of three herbicides which are on the list of priority substances according to Water Framework Directive (2000/60/EC). The aim was to obtain the data useful for prioritization on the basis of the new fundamental knowledge about (ad) sorption efficiency for the removal of these substances from the locally specific water matrices. Selected xenobiotics were differing in solubility, hydrophobicity, and donor-acceptor properties, which belong to different classes of compounds(trifluralin as herbicide, alachlor as chloracetamide herbicide and atrazine as triazine herbicide). In the first phase of the thesis characterization of sorbents and water matrices was performed. The aim of the second phase was the testing of the sorption anddesorption of organic xenobiotics in the sediments and organoclays. The equilibrium sorption parameters and removal efficiencies of herbicides were determined in different water matrices. In the synthetic matrix, trifluralin showed a higher sorption affinity onto tested sediments in comparison to the alachlor and atrazine. In the case of organoclays, sorption was mostly pronounced for trifluralin. Alachlor and atrazine have similar sorption capacities onto the TMA-K. For the TMA-B, the sorption was more pronounced for alachlor than atrazine. Depending on the natural water matrices, the highest Kd values were obtained for trifluralin onto both sediments. The Kd values for atrazine and alachlor were very similar or even greater for atrazine. In the case of organoclays, Kd values increased with increasing log KOW values of herbicides onto TMA-K in both natural matrices. When it comes to TMA-B, Kd valuesincreased with increasing log KOW values in the surface matrix forCe = 0,05 mg/l and 0,5 mg/l, and in groundwater at the highest equilibrium concentration C e = 0,5 mg/l. TMA-B (Kd = 10,5 - 483 l/kg) and model sediment (kd= 16,4 to 761 l/kg) were the most efficient s orbents. The absence of the clear linear correlation between Kd and % TOC indicates the importance of the interaction of mineral phases and herbicides. Correlation between K d and KOW values did not existed in the case of sediments, contrary to the organoclays. Since K d /KoW ratios were the h ighest for atrazine onto all sorbents, it was assumed that atrazine mostly participate in specific interactions due to its donor-acceptor properties. Regarding the influence of DOC on sorption, it was concluded that a comparison of sorbents efficiencies should be carried in native matrices as sorption coefficients vary depending on the concentration of pollutants, the type and content of DOC. Column experiments showed that atrazine and alachlor passed through the column of the sediment, while the trifluralin almost completely was adsorbed and in very low concentrations detected in the effluent which is in accordance with the results of the batch experiments. Estimated retardation factors of atrazine were higher in natural matrices (R d = 54 and Rd = 55 in groundwater and surface water, respectively) than in the synthetic water (Rd = 40). In the case of alachlor, retardation factors were similar among water matrices (Rd = 30-35). These results are in the opposition based on the xenobiotic hydrophilicity, and they could be the consequence of interaction with the organic matter present in the column tests, probably more than in the batch tests. Estimations of Rd based on batch tests did not show an increase of Rd values in natural matrices, in comparison to the synthetic matrix. More hydrophobic alachlor, in the circumstances of the sorbent matrix exerts similar (batch tests) or lower sorption (column tests) characteristics that indicate mobility through the first protective layer. The third phase included herbicide adsorption tests onto powdered activated carbons. The adsorption kinetics was examined by determining the intraparticle mass transfer coefficients for herbicides in raw and ozonated natural water matrices. The removal efficiencies of herbicides for different powdered activated carbons were determined. Removal efficiencies were in different ranges depending on the selected carbon, water matrix and carbon dose. The highest removal efficiencies for commercial carbons (for carbon dose of 15 mg/l) for alachlor were 95% and 76% in surface and groundwater, respectively. The highest removal of atrazine was 58% in surface water and 56% in groundwater. In thecase of trifluralin, removal efficiencies were 87% in surface water and 92% in groundwater. The removal efficiencies for the carbon with fine particles (usually used in combination with a membrane filtration) were greater. The removal of DOC by commercial carbons (at the dose of 15 mg/l) was less than 57% in the surface water and 47% in groundwater. A similar efficiency in DOC removal was achieved for the carbon with fine particles in both water matrices. Ozonation showed the expected negative influence on DOC removal efficiencies, more or less pronounced. In the case of xenobiotics, ozonation influence was different, depending on the applied carbon and xenobiotic. The most important negative influence was in the case of alachlor probably due to competition with organic matter or solubilization effect. The same, but less pronounced effect was observed for trifluralin. The positive influence of ozonation was observed in removal of atrazine by both commercial carbons but in different water matrices. One can speculate that it comes to the favorable distribution in new NOM coatings on carbons formed upon ozonation, which are sufficiently adsorbable, but with enough reactive qualities for association with polar substances, which is partly confirmed by the results of adsorption analysis.
D'Angelo, Emanuele. "(Nano)-compositi avanzati a matrice epossidica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7646/.
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