Estudo sobre a adsorção do fluido de perfuração salgado contendo polímeros sobre SiO2

Neto, João Crisósthomo de Queiroz; Biscaia, Evaristo C.; Petri, Denise Freitas Siqueira

doi:10.1590/s0100-40422007000400028

Cited by 6 publications

(4 citation statements)

References 15 publications

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“…Xanthan chains have the ability to build up physical networks with bivalent cations; the complex involves two disaccharide units of the main chain and O ‐acetyl and pyruvyl residues at side chains, leading to intramolecular cross‐linking and chains contraction, as revealed by conductometric and viscometric titrations and nuclear magnetic resonance spectroscopy . The binding of heavy metal ions, such as Cd 2+ and Pb 2+ , to xanthan chains seems to be stronger than to lighter cations, such as Ca 2+ and Mg 2+ (Ref.…”

Section: Xanthan Gum Networkmentioning

confidence: 99%

“…Because of its rheological properties and thermal stability, xanthan gum is used for drilling fluid rheology control, together with modified starch, which controls the fluid loss of drilling fluids . A typical water‐based drilling fluid formulation contains 4.28 g/L xanthan, 22.28 g/L modified starch and 100 g/L CaCO 3 , which has been used as weighting agent due to its high specific gravity . Weighting agents are added to adjust the density of drillings fluids, ensuring that its hydrostatic pressure is equal or larger than that of the pore pressure of the drilled formation and avoid fluid loss .…”

Section: Xanthan Gum As An Important Additive For Industrial and Techmentioning

confidence: 99%

“…Investigations about the flow behavior of solutions prepared with xanthan and CaCl 2 or Ca(NO 3 ) 2 at 100% stoichiometric equivalence (1: 1), and at Ca 2+ excess (1 : 10 and 1 : 100) evidenced that (i) the monovalent counter‐ion type (chloride or nitrate) has no influence on the flow consistency index or on the flow behavior index, (ii) the flow consistency index increased, as the ionic strength increased (1 : 100), mainly because the ordered state of xanthan chains was favored and (iii) the solutions became less pseudoplastic, as the ionic strength increased (1 : 100) . The flow behavior of xanthan solution in the presence of insoluble salts (CaSO 4 , CaCO 3 and Ca 3 (PO 4 ) 2 ) is particularly important for the development of drilling fluids because they act as weighting agent . Fluids containing particles with large density values and strong hydration, such as CaCO 3 and Ca 3 (PO 4 ) 2 , present high flow consistency indices, as discussed above.…”

Section: Xanthan Gum Networkmentioning

confidence: 99%

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Xanthan gum: A versatile biopolymer for biomedical and technological applications

Petri

2015

J of Applied Polymer Sci

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333

189

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Xanthan gum is an extracellular polymer produced mainly by the bacterium Xanthomonas campestris. Traditionally it plays an important role in industrial applications as thickener, emulsion stabilizer and it has been added to water-based drilling fluids due to its pseudoplastic behavior and thermal stability. The structural properties of xanthan in solution can be tuned by the temperature and ionic strength; under high ionic strength or low temperature, xanthan chains are arranged in helical conformation, whereas under low ionic strength or high temperature, xanthan chains are coiled. Xanthan high molecular weight favors the building up of physical and chemical networks, which have been used as carriers for drugs and proteins and as scaffolds for cells. In combination with other polymers xanthan has been applied as excipient in tablets or as supporting hydrogels for drug release applications, particularly due to its acid resistance. The large versatility of xanthan gum opens the possibility for the creation of new architectures and additional applications involving this fascinating polymer. AIMSThe purpose of this review is to report on the applications of xanthan gum in biomedical and technological products over the last ten years, but revisiting the background and the highlights of traditional applications as thickener. The in vivo biodegradability and biocompatibility of xanthan gum are fundamental characteristics that allow its use in biomedical applications. The ability to form networks and acid resistance make xanthan gum, as pure excipient or in combination with other polymers, very attractive as drug carriers. The recent combinations with inorganic particles open a range of new applications.

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Section: Xanthan Gum Networkmentioning

confidence: 99%

Section: Xanthan Gum As An Important Additive For Industrial and Techmentioning

confidence: 99%

Section: Xanthan Gum Networkmentioning

confidence: 99%

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Xanthan gum: A versatile biopolymer for biomedical and technological applications

Petri

2015

J of Applied Polymer Sci

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333

189

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“…Assim, a coluna de perfuração transmite torque do sistema de acionamento para a broca e a perfuração é promovida (JANSEN e VAN DEN STEEN, 1995;THOMAS, 2001). Durante o processo de perfuração, os cascalhos gerados são levados até a superfície por uma mistura denominada fluido ou lama de perfuração, que é bombeada por dentro da coluna e retorna pelo espaço anular existente entre o poço perfurado e a coluna de perfuração (FISCHER e COOK, 1951;QUEIROZ-NETO et al, 2007;NASIRI et al, 2009). Os processos de perfuração, bem como a produção petrolífera atual, só podem ser realizados devido a existência dos fluidos de perfuração, os quais são definidos como qualquer fluido circulante que auxilie a perfuração de poços de petróleo, poços tubulares e Persp.…”

Section: Introductionunclassified

Estudo das modificações das propriedades físico-químicas de fluidos de perfuração aquosos

Almeida

Dias

Terra³

2020

POEE

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O estudo das propriedades físico-químicas dos fluidos de perfuração é de grande importância para a indústria petrolífera. Nesse contexto, o presente trabalho teve por intuito sintetizar três fluidos de perfuração com diferentes composições químicas (Fluidos 1, 2 e 3), permitindo que algumas das suas propriedades fossem determinadas, tais como, densidade, parâmetros reológicos, filtrado e reboco, salinidade e pH. Após a realização das análises observou-se que o nitrato de bário não apresentou eficiência como adensante, pois sua adição afetou as interações entre as moléculas, gerando uma redução na viscosidade. Apesar do Fluido 2 apresentar algumas características interessantes para a indústria petrolífera a adição do adensante selecionado não foi adequada para o preparo desse fluido.

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Xanthan hydrogel films: Molecular conformation, charge density and protein carriers

Bueno

Petri

2014

Carbohydrate Polymers

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In this article the molecular conformation of xanthan chains in hydrogel films was investigated by means of circular dichroism, showing substantial differences between xanthan hydrogel prepared in the absence (XNT) and in the presence of citric acid (XCA). The xanthan chains in XNT hydrogels films presented ordered conformation (helixes), while in XCA they were in the disordered conformation (coils), exposing a larger number of carboxylate groups than XNT. The large charge density in XCA hydrogels was evidenced by their behavior under variable ionic strength. Studies about the application of XNT and XCA for loading and delivering of bovine serum albumin (BSA) and lysozyme (LYZ) showed that both events are controlled by hydrogels and proteins net charge, which can be triggered by pH. The preservation of LYZ native conformation after hydrogel loading explained the substantial bactericidal activity of LYZ loaded hydrogels and enables their use as active wound dressings.

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Estudo sobre a adsorção do fluido de perfuração salgado contendo polímeros sobre SiO2

Cited by 6 publications

References 15 publications

Xanthan gum: A versatile biopolymer for biomedical and technological applications

Xanthan gum: A versatile biopolymer for biomedical and technological applications

Estudo das modificações das propriedades físico-químicas de fluidos de perfuração aquosos

Xanthan hydrogel films: Molecular conformation, charge density and protein carriers

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