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•Biosynthesized (SiO2@Montmorilant@Xanthan) NCs have silica as predominant phase.•SiO2@Montmorilant@Xanthan) NCs have reduced IFT by 56%.•SiO2@Montmorilant@Xanthan) NCs at optimum ...concentrations have shifted wettability from oil-wet to strongly water-wet.•Total oil recovery was increased by 15.8% in sandstone samples and 11.72% in carbonate samples.
Nanoparticles are used in various nano-energy applications such as wettability shift of hydrophobic surfaces to hydrophilic surfaces in oil-brine-mineral systems and interfacial tension (IFT) reduction for enhanced oil recovery. This is possible due to their small size (1–100 nm) and chemical and physical properties. Mechanistically, they can interact with a fluid in the pore space and provide favourable conditions for wettability shift, IFT and oil viscosity reduction, and thus improve oil recovery. However, literature is scarce in terms of providing comprehensive information about the behaviour of nanocomposites (NCs) and associated formulations.
In this paper, we present biosynthesis, characterization, and application of a novel nanocomposite (SiO2@Montmorilant@Xanthan) which is used with various concentrations (100, 250, 500, 1000, 1500, and 2000 ppm) as dispersing agents in porous media. The NC was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), and Energy Dispersive Spectroscopy (EDS). The effects of different concentrations of the nano-suspensions on zeta potential, pH, conductivity, IFT, and wettability are investigated. Core flooding tests were done on sandstone and carbonate reservoir rocks to measure the secondary and tertiary recovery potential by injecting seawater and optimum NC concentrations, respectively.
Zeta potential and conductivity experiments demonstrated that 250 ppm NCs can optimally reduce the IFT from 36 mN/m to 15.42 mN/m (56% reduction). The similar optimum concentration has shifted the wettability of examined carbonate rocks from 150° to 33° leading to an 11.72% increase in tertiary oil recovery. Whereas, the optimum concentration of NCs for sandstone rocks was 1000 ppm; which, has optimally altered the wettability from 140° to 34°, and has increased the tertiary oil recovery by 15.79%. This reduction in IFT, the reversal of wettability, and an increase in tertiary oil recovery can improve significantly the design of effective enhanced oil recovery schemes for petroleum reservoirs.
To investigate the effect of surfactants in compound solution on the wetting-agglomeration properties of the bituminous coal dust, this paper selected anionic surfactants SDS, SDBS and non-ionic ...surfactants APG0810 and PPG400 for compounding with agglomerated solutions 0.05 wt% XTG (xanthan gum). The sink test, surface tension test, viscosity test, fourier transform infrared spectroscopy(FTIR) and scanning electron microscope(SEM) were used to investigate the wettability and agglomeration of the four compound solutions and analyze the agglomeration wetting mechanism. The results show that SDBS has the most obvious improvement in the wettability of compound solution. The surface tension of SDBS + 0.05 wt% XTG is 28.98 mN/m after CMC value and sinking rate will reach 14.29 mg/s with 0.6 wt% SDBS in compound solution; Furthermore, FTIR results showed that surface hydroxyl content of bituminous coal dust treated by 0.2 wt% SDBS + 0.05 wt% XTG solutions has increased 26.3% than that treated by 0.05 wt% XTG, which promoted the adsorption of xanthan gum molecules on the coal surface. The presence of surfactants decreases the viscosity and surface tension of compound solution, and xanthan gum–surfactants interaction will promote bituminous coal dust agglomeration effect. This agglomeration mechanism is mainly reflected in the distribution mechanism and bituminous coal dust can form to large agglomerates under this action.
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•Influence mechanism of surfactants in compound solution on viscosity is analyzed.•Wetting-agglomeration properties of coal dust by composite reagent are studied.•The distribution mechanism about coal dust agglomeration has been found.•The formed process of distribution mechanism has been described.
Synergistic interaction gels (SIGs) hold immense promise for applications in 3D printing, colonic drug delivery, and sustained release. The amalgamation of xanthan and tamarind gum (TMG) gives rise ...to SIGs through molecular interaction; however, the intricacies of their assembly behaviors remain elusive. This work elucidates that in xanthan-rich systems, the predominant formation of xanthan aggregations shapes network assembly structure, with TMG clusters adhering to them. Conversely, in TMG-rich systems, TMG clusters actively participate in creating a “sea-island” assembly structure enveloped by xanthan aggregations. Higher concentration of TMG contributes to augmenting the association extent of TMG and xanthan. The heightened binding between TMG and xanthan correlates with an increase in chain distance in scatters and the compactness of scatter arrangement. These favor the development of micro-structures with a relatively larger mesh size and the enhancement of gel hardness. This study serves to facilitate the design and production of SIGs-based artificial gel foods with the requisite performance characteristics, such as artificial sea cucumber and porcine back fat.
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•Xanthan aggregation shapes network structure in xanthan-rich system.•“Sea-island” structure is formed in tamarind gum (TMG)-rich system.•Higher TMG content increases association extent of xanthan and TMG.•Higher association extent causes higher gel hardness of TMG/xanthan SIGs.
The extracellular heteropolysaccharide xanthan, synthesized by bacteria of the genus
Xanthomonas
, is widely used as a thickening and stabilizing agent across the food, cosmetic, and pharmaceutical ...sectors. Expanding the scope of its application, current efforts target the use of xanthan to develop innovative functional materials and products, such as edible films, eco-friendly oil surfactants, and biocompatible composites for tissue engineering. Xanthan-derived oligosaccharides are useful as nutritional supplements and plant defense elicitors. Development and processing of such new functional materials and products often necessitate tuning of xanthan properties through targeted structural modification. This task can be effectively carried out with the help of xanthan-specific enzymes. However, the complex molecular structure and intricate conformational behavior of xanthan create problems with its enzymatic hydrolysis or modification. This review summarizes and analyzes data concerning xanthan-degrading enzymes originating from microorganisms and microbial consortia, with a particular focus on the dependence of enzymatic activity on the structure and conformation of xanthan. Through a comparative study of xanthan-degrading pathways found within various bacterial classes, different microbial enzyme systems for xanthan utilization have been identified. The characterization of these new enzymes opens new perspectives for modifying xanthan structure and developing innovative xanthan-based applications.
Key points
• The structure and conformation of xanthan affect enzymatic degradation.
• Microorganisms use diverse multienzyme systems for xanthan degradation.
• Xanthan-specific enzymes can be used to develop xanthan variants for novel applications.
The periosteum is a membrane that surrounds bones, providing essential cellular and biological components for fracture healing and bone repair. Tissue engineered scaffolds able to function as ...periosteum substitutes can significantly improve bone regeneration in severely injured tissues. Efforts to develop more bioactive and tunable periosteal substitutes are required to improve the success of this tissue engineering approach. In this work, a chemical modification was performed in chitosan, a polysaccharide with osteoconductive properties, by introducing phosphate groups to its structure. The phosphorylated polymer (Chp) was used to produce chitosan-xanthan-based scaffolds for periosteal tissue engineering. Porous and mechanically reinforced matrices were obtained with addition of the surfactant Kolliphor® P188 and the silicone rubber Silpuran® 2130A/B. Scaffolds properties, such as large pore sizes (850–1097 μm), micro-roughness and thickness (0.7–3.5 mm in culture medium), as well as low thrombogenicity compared to standard implantable materials, extended degradation time and negligible cytotoxicity, enable their application as periosteum substitutes. Moreover, the higher adsorption of bone morphogenetic protein mimic (cytochrome C) by Chp-based formulations suggests improved osteoinductivity of these materials, indicating that, when used in vivo, the material would be able to concentrate native BMPs and induce osteogenesis. The scaffolds produced were not toxic to adipose tissue-derived stem cells, however, cell adhesion and proliferation on the scaffolds surfaces can be still further improved. The mineralization observed on the surface of all formulations indicates that the materials studied have promising characteristics for the application in bone regeneration.
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•Bifunctional Zr@XG-ZA was synthesized by encapsulation and anchoring method.•Incorporation of ZA and anchoring of Zr was evidenced by TEM, SEM–EDX, FTIR studies.•Adsorption of REEs ...on Zr@XG-ZA in multicomponent system was higher than single system.•REE doped nanocomposite was efficient enough to use as photocatalyst for tetracycline.
The work focus to enhance the properties of xanthan gum (XG) by anchoring metal ions (Fe, Zr) and encapsulating inorganic matrix (M@XG-ZA). The fabricated nanocomposite was characterized by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), surface area (BET) and zeta potential analysis. The adsorption of Sc, Nd, Tm and Yb was investigated after screening of synthesized materials in detail to understand the influence of pH, contact time, temperature and initial REE (rare earth element) concentration both in single and multicomponent system via batch adsorption. The adsorption mechanism was verified by FTIR, SEM and elemental mapping. The SEM images of Zr@XG-ZA demonstrate scutes structure, which disappeared after adsorption of REEs. The maximum adsorption capacities were 132.30, 14.01, 18.15 and 25.73 mg/g for Sc, Nd, Tm and Yb, respectively. The adsorption efficiency over Zr@XG-ZA in multicomponent system was higher than single system and the REEs followed the order: Sc > Yb > Tm > Nd. The Zr@XG-ZA demonstrate good adsorption behavior for REEs up to five cycles and then it can be used as photocatalyst for the degradation of tetracycline. Thus, the work adds a new insight to design and preparation of efficient bifunctional adsorbents from sustainable materials for water purification.
Interactions between xanthan gum and phenolic acids Theocharidou, Athina; Lousinian, Sylvie; Tsagkaris, Apostolos ...
International journal of biological macromolecules,
July 2024, 2024-07-00, 20240701, Letnik:
273, Številka:
Pt 2
Journal Article
Recenzirano
The molecular and colloidal-level interactions between two major phenolic acids, gallic and caffeic acid, with a major food polysaccharide, xanthan gum, were studied in binary systems aiming to ...correlate the stability of the binary systems as a function of pH and xanthan-polyphenol concentrations. Global stability diagrams were built, acting as roadmaps for examining the phase separation regimes followed by the fluorimetry-based thermodynamics of the interactions. The effects of noncovalent interactions on the macroscopic behavior of the binary systems were studied, using shear and extensional rheometry. The collected data for caffeic acid – xanthan gum mixtures showed that the main interactions were pH-independent volume exclusions, while gallic acid interacts with xanthan gum, especially at pH 7 with other mechanisms as well, improving the colloidal dispersion stability. A combination of fluorimetry, extensional rheology and stability measurements highlight the effect of gallic acid-induced aggregation of xanthan gum, both in structuring and de-structuring the binary systems. The above provide a coherent framework of the physicochemical aspect of binary systems, shedding light on the role of xanthan gum in its oral functions, such as in inducing texture, in model complex systems containing phenolic acids.
•Volume exclusion interactions dominate the behavior of xanthan–caffeic acid mixtures.•Caffeic acid acts as a filler material in xanthan solutions.•Gallic acid exothermically interacts with xanthan gum.•Gallic acid enthalpically influences xanthan gum's relaxation time.•The phase stability of gallic acid – xanthan gum depends of the former's concentration.
In light of the need to create new materials that are safe for use in biomedical applications like wound healing and tissue engineering, a unique nanocomposite was formulated and produced in the ...current investigation. A biocompatible hydrogel was created using natural polymers xanthan gum (XG) and alginate (Alg). In order to enhance the mechanical characteristics of the natural polymer-based hydrogels, polyvinyl alcohol (PVA) was added to the hydrogel matrix. Subsequently, the XG-Alg hydrogel/PVA structure was combined with ZnMnFe2O4 nanoparticles in order to augment the antibacterial efficacy of the biomaterial. The XG-Alg hydrogel/PVA/ZnMnFe2O4 nanocomposite was analyzed using XRD, EDX, FT-IR, TGA, and FE-SEM techniques to determine its properties. In addition, the mechanical properties of the pure hydrogel were compared to those of the XG-Alg hydrogel/PVA/ZnMnFe2O4 nanocomposite. The nanocomposite exhibited a biocompatibility of 96.45 % and 94.32 % with HEK293T cell lines after 24 h and 48 h of incubation, respectively, in biological evaluations. Furthermore, a significant antibacterial efficacy was demonstrated against both gram-positive S. aureus and gram-negative E. coli bacteria. The findings suggest that the developed XG-Alg hydrogel/PVA/ZnMnFe2O4 nanocomposite has promising qualities for use in biomedical fields, such as tissue engineering.
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•Xanthan-chitosan mixture (X-Ch) forms ionically associated electrospun nanofibers (NF).•X-Ch NF are stable in aqueous media, and encapsulate and deliver curcumin (Cu).•X-Ch NF open ...Caco-2 cells tight junctions and enhance Cu transepithelial transport.•A 3.4-fold increase of Cu permeability observed in the presence of X-Ch nanofibers.•NF-epithelial cells interactions can be used to increase the oral uptake of bioactives.
Xanthan-Chitosan (X-Ch) polysaccharides nanofibers were prepared using electrospinning processing as an encapsulation and delivery system of curcumin (Cu). The X-Ch-Cu nanofibers remained stable in aqueous HBSS medium at pH 6.5 and pH 7.4, mainly due to the ability of oppositely charged xanthan-chitosan polyelectrolytes to form ionically associated electrospun nanofibers. The xanthan-chitosan-curcumin nanofibers were incubated with Caco-2 cells, and the cell viability, transepithelial transport and permeability properties across cell monolayers were investigated. After 24 h of incubation, the exposure of Caco-2 cell monolayers to X-Ch-Cu nanofibers resulted in a cell viability of ∼80%. A 3.4-fold increase of curcumin permeability was observed when the polyphenol was loaded into X-Ch nanofibers, compared to the free curcumin. This increased in vitro transepithelial permeation of curcumin without compromising cellular viability was induced by interactions upon contact between the nanofibers and the Caco-2 cells, leading to the opening of the tight junctions. The results obtained revealed that X-Ch nanofibers can be used for oral delivery applications of poorly water-soluble compounds at the gastrointestinal tract.
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