Membranes from Nylon 6/Regional Bentonite Clay Nanocomposites

Leite, Amanda Melissa Damião; Medeiros, Keila Machado de; Araújo, Edcleide Maria; Maia, Larissa Fernandes; Lira, Hélio Lucena; Paz, Renê Anísio da

doi:10.4028/www.scientific.net/msf.660-661.784

Cited by 10 publications

(13 citation statements)

References 10 publications

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“…5 (b), the appearance of a peak at 4° is observed, probably due to a partial intercalation of the polymer between the lamellae of the clay. In addition, it was found that the intensity of this peak was proportional to the increase of the percentage of clay added in the polyamide membrane [40][41][42].…”

Section: Resultsmentioning

confidence: 95%

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Influence of Additives on Hybrids Membranes Morphology for Water Treatment

Filho

Salviano

Araújo

et al. 2017

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In this work, polyamide 6 membranes (PA6) and hybrids with 1, 3 and 5% of montmorillonite clay (MMT) were obtained, adding potassium chloride (KCl) and calcium chloride (CaCl2). These different additives are intended to promote formation and increase of the pores in the microporous membranes. The membranes in the form of thin films were prepared by the phase inversion technique, leading to flat selective barriers. The MMT clay was characterized by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The membranes were characterized by XRD, FTIR, scanning electron microscopy (SEM), contact angle, water vapor permeation, flow measurements and yield. The clay XRD results showed characteristic peaks of bentonite containing accessory materials, as well as a peak at 5.93°, indicating the d001basal interplanar distance of 14.95 Å of MMT. In the spectrum in the infrared region of the clay, it was observed the presence of hydroxyls inherent to the adsorbed water, as well as characteristic bands of Si-O-Si bonds and the octahedral layer of MMT. The viscosities of the solutions of PA6 and their hybrids with CaCl2were higher compared to solutions containing KCl due the CaCl2possess a bivalent ion with a high degree of hydration and a molecular mass higher than KCl. In addition, these salts promote formation of hydroxides that precipitate the particles of MMT, decreasing the viscosities with the increasing percentage of clay. By means of the X-ray diffraction, it was possible to perceive that the hybrid membranes with the inorganic salts suggest an exfoliated and/or partially exfoliated structure. From the results of the FTIR analysis the bands obtained in the PA6 membranes and its hybrids remained practically unchanged, as there was an increase in the clay content and the introduction of the inorganic salts. From the photomicrographs obtained by SEM, it was observed that the addition of clay in the hybrid membranes provided an increase in the number of pores with the gradual increase of the percentage of clay. While the addition of the inorganic salts (KCl and CaCl2) provided an increase in the pore size of the top surfaces of all membranes, by means of the contact angle, it was verified that the hybrid membranes presented smaller angles when compared to the PA6, probably, due to the superficial peculiarity of the clay to react with water. PA6 membranes with KCl and CaCl2showed lower water vapor permeations as compared to hybrid membranes due to the increase in the size and quantity of pores presented on their top surfaces. The distilled water flow in the membranes initially showed a decrease and after 30 minutes a stability of the permeate flow due to a compression occurred in the membranes. The water-oil separation tests of the membranes with CaCl2, regardless of the pressure used, indicated a significant reduction of permeate oil with promising yields above 87% , presenting potential for the treatment of wastewater contaminated by oil.

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Section: Resultsmentioning

confidence: 95%

“…Several sources of water from industries typically contain oil, which has become the most common pollutant in the world. In recent years, it is possible to find a large amount of research on membranes for the treatment of oily wastewater in the literature, not only in experimental, but also in theoretical terms [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Influence of Additives on Hybrids Membranes Morphology for Water Treatment

Filho

Salviano

Araújo

et al. 2017

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“…The bentonite untreated clay (UC) was organically modified by ion exchange reaction in aqueous solution using Cetremide® quaternary ammonium salt according to the cation exchange capacity (CEC) of clay [7][8][9][10]. This clay was called treated clay (TC).…”

Section: Preparation Of Organoclaymentioning

confidence: 99%

“…20th Brazilian Conference on Materials Science and Engineering Figures 4a, 5a e 6a illustrate the SEM photomicrographs of the top surface of membranes of pure PA66 and their nanocomposites with 3% w/w of UC and TC, respectively. The image of the membranes shows a structure with low porosity or small pore size, presenting a dense structure in your surfaces [19,20].…”

Section: Materials Science Forum Vols 775-776mentioning

confidence: 99%

Study of Morphology Membrane of Polymeric Nanocomposites Obtained by Phases Inversion

Medeiros

Silva

Morais

et al. 2014

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In this work, were obtained nanocomposite membranes polyamide66/Paraíba bentonite clay, treated with a quaternary ammonium salt in order to make it organophilic. The membranes were prepared as thin films using the technique of phase inversion from the nanocomposites obtained by solution. The membranes were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and scanning electron microscopy (SEM). By means of X-ray diffractogram, it was revealed that the membranes remained organically treated clay presented exfoliated and/or partially exfoliated structure. From curves of DSC and TG, it was observed that membrane of PA66 with 3% w/w of with treatment clay showed higher thermal stability compared with the same content of clay without treatment. From the SEM photomicrographs, there was a selective layer (skin filter) on top and one porous layer at the bottom of all membranes studied. Moreover, it was verified that the presence of clay provided a significant structural modification in the membranes of polymer nanocomposites.

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“…esses planos cristalinos para o mesmo polímero [17][18][19][20] . A reflexão em 21,4° do plano cristalino (001) é atribuída à fase γ do polímero, podendo também ocorrer na reflexão de 10,8°, coerente com as reflexões encontradas na literatura [18] .…”

Section: Leite a M D Et Al -Obtenção De Membranas Microporosas Aunclassified

Obtenção de Membranas Microporosas a partir de Nanocompósitos de Polimida 6/Argila Nacional. Parte 2: Avaliação Microestrutural e de Permeabilidade das Membranas Obtidas

Leite¹,

Araújo²,

Lira³

et al. 2014

Polímeros

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Resumo: Membranas de híbridos orgânico/inorgânico de poliamida 6 e argilomineral constituído de silicatos em camadas foram estudadas em comparação com o polímero puro. Uma argila sódica, como recebida da indústria, e outra organofilizada com os sais quaternários de amônio Dodigen e Cetremide foram utilizadas. Os sais tornam hidrofóbica a superfície da argila e favorecem sua incorporação na matriz polimérica no estado fundido. A partir dos nanocompósitos obtidos foram preparadas membranas por meio da técnica de imersão-precipitação, tendo como solvente o ácido fórmico e como método de produção a precipitação em um banho de água (não-solvente). O teor do ácido nas soluções poliméricas, dos híbridos e da poliamida 6 pura, foi variado para avaliar sua influência na morfologia e na permeabilidade das membranas produzidas. As membranas apresentaram morfologia assimétrica, constituída de uma pele filtrante e um suporte poroso. A presença da argila tratada com os diferentes sais alterou a formação dos poros, tanto na superfície como na seção transversal. As partículas de argila provavelmente atuaram como barreira ao fluxo. Observou-se ainda que o teor de ácido utilizado influenciou de forma significativa a estrutura assimétrica da membrana; quanto maior o teor de ácido maior a espessura da pele filtrante. O teor de ácido também levou à alteração do tamanho e da distribuição dos poros. As medidas de fluxo realizadas com os dois teores de ácido diferentes mostraram uma resposta em função da morfologia diferenciada obtida. Palavras-chave: Membranas, nanocompósitos, poliamida 6, argila bentonítica, teor de ácido. Microporous Membranes from Polyamide6/National Clay Nanocomposites. Part 2: Microstructural and Permeability EvaluationAbstract: Organic/inorganic hybrid membranes of polyamide 6 and mineral clay containing layers of silicate were prepared and compared to those of the pure polymer. Use was made of an as-received sodium clay from industry and another organophilized with ammonium quaternary salts (Dodigen and Cetremide). The salts make the clays surface hydrophobic and improve their incorporation into the polymer matrix in the molten state. Membranes were prepared with these nanocomposites using the immersion-precipitation technique with formic acid as a solvent, and precipitation in a water bath as non-solvent. The acid concentration in the solution containing the polymer and the hybrids was varied to study its influence in morphology and permeability of the membranes. An asymmetric morphology consisting of a filter skin and a porous support was observed, with pores both on the surface and in the cross section being affected by the different salts. This asymmetric morphology was also affected significantly by the acid concentration, with thicker filter skins for higher concentrations. The acid concentration affected the pores size and their distribution. The clay particles probably acted as a barrier to the flow. The permeating flux for the two acid concentrations varied as a function of the distinct morphologies.

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Membranes from Nylon 6/Regional Bentonite Clay Nanocomposites

Cited by 10 publications

References 10 publications

Influence of Additives on Hybrids Membranes Morphology for Water Treatment

Influence of Additives on Hybrids Membranes Morphology for Water Treatment

Study of Morphology Membrane of Polymeric Nanocomposites Obtained by Phases Inversion

Obtenção de Membranas Microporosas a partir de Nanocompósitos de Polimida 6/Argila Nacional. Parte 2: Avaliação Microestrutural e de Permeabilidade das Membranas Obtidas

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