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You searched for subject:(Colligative properties). Showing records 1 – 2 of 2 total matches.

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University of Oklahoma

1. Warren, Michael. UNDERSTANDING SPECIFIC ION EFFECTS AND INTERFACIALLY ACTIVE SOLUTES USING THE COLLIGATIVE PROPERTIES OF MICROEMULSIONS.

Degree: PhD, 2020, University of Oklahoma

Designing and optimizing surfactant formulations continues to be of great interest to many industrial endeavors. Many of these applications utilize an assortment of ingredients including electrolytes, alcohols and other interfacially active solutes. Using the Hydrophilic Lipophilic Deviation (HLD), and specifically Type III microemulsion structures, changes to amphiphilic behavior can be quantified. This study highlights the use of HLD parameters in predicting optimal formulations as well as approximating unknown surfactants using specific molar ratios of the binary surfactants. Mixtures of heterogeneous surfactants were evaluated and the nonideality determined, where the highest deviation was found using anionic-nonionic solutions. Further, the structure of the amphiphiles were considered using their respective HLD parameters, providing evidence that the K value relates to the lipophile length and may be observed in changes in surfactant solubility. Cc values were found to be analogous to HLB values and empirical regressions were provided for quick approximation. This work considered the colligative properties of microemulsions to address the effects of additional solutes to amphiphilic behavior. It was demonstrated that specific cations as well as interfacially active solutes like alcohols are able to shift surfactant HLD parameters as well as the microemulsion properties such as the solubilization parameter. A proposed colligative hydration model was successfully implemented, providing better predictions of optimum salinities for chloride salts for anionic amphiphiles than what is found in literature. The use of nonionic reference surfactant suggests the specific ion effects behave similarly towards an uncharged molecule as the colligative hydration numbers, hC, remained consistent. This approach was extended to alcohols where the hc values qualitatively agreed with the alcohol’s hydrodesimic numbers, hD, found through freezing point depressions. The general trend of increasing the alcohol alkyl length was observed, decreasing the alcohol's ability to interact with free interfacial water as it tends to partition further into the surfactant palisade layer. Ultimately the colligative approach provided evidence that the additive properties of polar solutes appear within the changes in amphiphilic behavior and can be utilized properly to return HLD to a colligative equation. Such an approach should be widely beneficial as formulators now can quickly screen and predict optimum formulations by simply using common additive properties of solutes such as size, valency, and hydration. Advisors/Committee Members: Harwell, Jeffrey (advisor), Shiau, Benjamin (Bor-Jier) (committee member), Haung, Paul (Liangliang) (committee member), Walters, Keisha (committee member), Galizia, Michele (committee member).

Subjects/Keywords: Colligative Properties; Microemulsions; Hydrophilic Lipophilic Deviation; Specific Ion Effects; Amphiphiles

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Warren, M. (2020). UNDERSTANDING SPECIFIC ION EFFECTS AND INTERFACIALLY ACTIVE SOLUTES USING THE COLLIGATIVE PROPERTIES OF MICROEMULSIONS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/325155

Chicago Manual of Style (16th Edition):

Warren, Michael. “UNDERSTANDING SPECIFIC ION EFFECTS AND INTERFACIALLY ACTIVE SOLUTES USING THE COLLIGATIVE PROPERTIES OF MICROEMULSIONS.” 2020. Doctoral Dissertation, University of Oklahoma. Accessed November 25, 2020. http://hdl.handle.net/11244/325155.

MLA Handbook (7th Edition):

Warren, Michael. “UNDERSTANDING SPECIFIC ION EFFECTS AND INTERFACIALLY ACTIVE SOLUTES USING THE COLLIGATIVE PROPERTIES OF MICROEMULSIONS.” 2020. Web. 25 Nov 2020.

Vancouver:

Warren M. UNDERSTANDING SPECIFIC ION EFFECTS AND INTERFACIALLY ACTIVE SOLUTES USING THE COLLIGATIVE PROPERTIES OF MICROEMULSIONS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2020. [cited 2020 Nov 25]. Available from: http://hdl.handle.net/11244/325155.

Council of Science Editors:

Warren M. UNDERSTANDING SPECIFIC ION EFFECTS AND INTERFACIALLY ACTIVE SOLUTES USING THE COLLIGATIVE PROPERTIES OF MICROEMULSIONS. [Doctoral Dissertation]. University of Oklahoma; 2020. Available from: http://hdl.handle.net/11244/325155

2. Menezes, Jean Michel dos Santos. Atividades experimentais investigativas no ensino de propriedades coligativas: possibilidades para aprender significativamente.

Degree: 2018, Universidade Federal do Amazonas

Os experimentos investigativos são atividades que exigem do aluno uma participação mais ativa, e com isso, auxiliam no desenvolvimento de habilidades importantes no processo de aprendizagem. Propriedades Coligativas, se apresenta, na literatura, como um dos conteúdos químicos mais difíceis de entender, além disso, existe uma certa ausência de trabalhos que abordem experimentos voltados ao mesmo. Diante disso, este trabalho teve como objetivo analisar as contribuições de atividades experimentais investigativas no desenvolvimento de habilidades investigativas, mediante a construção de conceitos relacionados ao conteúdo Propriedades Coligativas, por estudantes da 2ª série do Ensino Médio. A presente pesquisa foi pautada na teoria de aprendizagem de David Ausubel, a Teoria da Aprendizagem Significativa. Assim, buscou-se, inicialmente, identificar os conhecimentos prévios dos alunos por meio de um questionário, e após isso, foi elaborada uma sequência didática com as atividades investigativas que seriam realizadas. Além do questionário, outros instrumentos de coleta de dados foram utilizados, como as fichas de atividade, mapas conceituais e observação, que foi realizada por meio audiovisual e diário de campo. Coletaram-se os dados em uma Escola Estadual da cidade Manaus-AM, com vinte estudantes, em um curso de quarenta horas. De um modo geral, os alunos apresentaram algumas dificuldades em relação aos conhecimentos prévios sobre o assunto. Durante a execução das atividades, os alunos mostraram entusiasmo em participar e uma evolução na autonomia de acordo com o aumento dos níveis de investigação que cada atividade requeria. Os mapas conceituais indicaram que os alunos conseguiram realizar relações entre os conceitos, porém, em sua maioria, não conseguiram utilizar palavras de ligação, o que dificultou a análise dessas relações. Dentre as habilidades investigativas desenvolvidas pelos alunos, podemos destacar manipulação de materiais, observação, formulação de hipóteses, organização e análise dos dados, conclusão.

Investigative experiments are activities that require the student to participate more actively, and with this, help in the development of important skills in the learning process. Colligative Properties, is presented in the literature as one of the most difficult to understand chemical contents, besides, there is a certain absence of works that approach experiments oriented to it. Therefore, the present study had the objective of analyze the contributions of experimental investigative activities in the development of investigative capacities, through the construction of concepts related to the content Colligative Properties, of the second year of High School. This research was based on the learning theory of David Ausubel, the Theory of Meaningful Learning. Thus, it was initially sought to identify the students' previous knowledge through a questionnaire, and after that, a didactic sequence was elaborated with the investigative activities that would be carried out. In addition to the questionnaire, other…

Advisors/Committee Members: Farias, Sidilene Aquino de, 41385063220, http://lattes.cnpq.br/6974383103784984, Antunes, Ettore Paredes, Azevedo, Rosa Oliveira Marins, [email protected].

Subjects/Keywords: Aprendizagem significativa; Experimentação investigativa; Propriedades coligativas; Meaningful learning; Investigative experimental; Colligative properties; CIÊNCIAS EXATAS E DA TERRA: QUÍMICA

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Menezes, J. M. d. S. (2018). Atividades experimentais investigativas no ensino de propriedades coligativas: possibilidades para aprender significativamente. (Masters Thesis). Universidade Federal do Amazonas. Retrieved from https://tede.ufam.edu.br/handle/tede/6408

Chicago Manual of Style (16th Edition):

Menezes, Jean Michel dos Santos. “Atividades experimentais investigativas no ensino de propriedades coligativas: possibilidades para aprender significativamente.” 2018. Masters Thesis, Universidade Federal do Amazonas. Accessed November 25, 2020. https://tede.ufam.edu.br/handle/tede/6408.

MLA Handbook (7th Edition):

Menezes, Jean Michel dos Santos. “Atividades experimentais investigativas no ensino de propriedades coligativas: possibilidades para aprender significativamente.” 2018. Web. 25 Nov 2020.

Vancouver:

Menezes JMdS. Atividades experimentais investigativas no ensino de propriedades coligativas: possibilidades para aprender significativamente. [Internet] [Masters thesis]. Universidade Federal do Amazonas; 2018. [cited 2020 Nov 25]. Available from: https://tede.ufam.edu.br/handle/tede/6408.

Council of Science Editors:

Menezes JMdS. Atividades experimentais investigativas no ensino de propriedades coligativas: possibilidades para aprender significativamente. [Masters Thesis]. Universidade Federal do Amazonas; 2018. Available from: https://tede.ufam.edu.br/handle/tede/6408

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