Solution Properties of Partially Hydrolysed Polyacrylamide and Chitosan Mixed Solutions

Vidal, Rosangela Regia Lima; Fagundes, Fábio Pereira; Menezes, Sônia Maria Cabral de; Ruiz, Naira Machado da Silva; Garcia, Rosangela B.

doi:10.1002/masy.200551114

Cited by 15 publications

(4 citation statements)

References 27 publications

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“…Its viscosity-average molecular weight was 4.9 x 10 4 g mol -1 , estimated at 25°C in 0.3 M acetic acid/0.2 M sodium acetate. Its degree of deacetylation was 76.5%, determined by proton nuclear magnetic resonance 1 H NMR, according to procedures described elsewhere Lima Vidal, Pereira Fagundes [30]. Glutaraldehyde was obtained from Sigma-Aldrich.…”

Section: Methodsmentioning

confidence: 99%

Prolonged mosquitocidal activity of Siparuna guianensis essential oil encapsulated in chitosan nanoparticles

et al. 2019

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Background The use of synthetic insecticides is one of the most common strategies for controlling disease vectors such as mosquitos. However, their overuse can result in serious risks to human health, to the environment, as well as to the selection of insecticidal resistant insect strains. The development of efficient and eco-friendly insect control is urgent, and essential oils have been presented as potential alternatives to synthetic insecticides. Moreover, nanoencapsulation techniques can enhance their efficiency by protecting from degradation and providing a controlled release rate. Results We assessed the potential of chitosan nanoparticles in encapsulating Siparuna guianensis essential oil, and maintaining its efficiency and prolonging its activity for the control of Aedes aegypti larvae. The encapsulation was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), with an encapsulation efficiency ranging from 84.8% to 88.0%. Toxicity studies have demonstrated efficacy against mosquito larvae over 50% for 19 days with 100% mortality during the first week. This persistent action is presumably due to the enhanced contact and slow and maintained release conferred by chitosan nanoparticles. Furthermore, the exposure of aquatic non-target organisms (e.g. embryos and small adult fishes) revealed adequate selectivity of these nanoparticles. Conclusions The encapsulation of S . guianensis essential oil in chitosan nanoparticles showed promising potential as a larvicide control alternative and should be considered within strategies for fighting Ae . aegypti .

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Section: Methodsmentioning

confidence: 99%

Prolonged mosquitocidal activity of Siparuna guianensis essential oil encapsulated in chitosan nanoparticles

et al. 2019

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“…The effect could be explained by the fact that ethoxy groups form hydrogen bonds with the acrylamide‐based polymer. These types of polymers make hydrogen bonds with other molecular species due to the presence of the carbonyl group (Hu et al, ; Lima Vidal et al, ). Moreover, the ability of ethoxy groups to form hydrogen bonds with polymers was reported in other surfactant–polymer systems (Robb and Stevenson, ).…”

Section: Resultsmentioning

confidence: 99%

Development of Polyoxyethylene Zwitterionic Surfactants for High‐Salinity High‐Temperature Reservoirs

Kamal

Hussain

Fogang

et al. 2019

J Surfact & Detergents

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Substantial efforts are underway to improve the recovery factor from existing oil reserves to meet the ever‐growing global oil demand. Surfactants are known to increase oil recovery through reducing interfacial tension (IFT) and/or altering the rock wettability. The selection of surfactants for high‐salinity high‐temperature oil fields is a challenging task owing to poor thermal stability, precipitation, and adsorption of surfactants on reservoir rocks. Sulfobetaine‐based polyoxyethylene zwitterionic surfactants have shown excellent thermal and surface properties. However, their solubility in high‐salinity brines becomes poor particularly with a long hydrophobic tail (>C17). Recently, we synthesized such types of surfactants by incorporating ethylene oxide (EO) units into the hydrophobic tail, which improved the solubility in formation water (213,734 ppm) and seawater (SW) (57,643 ppm). In this work, we investigated the IFT, thermal stability, rheological behavior, and foaming properties of two polyoxyethylene zwitterionic surfactants having different degrees of ethoxylation. Aging experiments exhibited excellent thermal stability and no change in the chemical structure was detected. The surfactant with lesser EO units (EASB‐1a) showed a lower IFT compared to the surfactant with higher EO units (EASB‐1b). Rheological studies revealed that the addition of both surfactants reduced the viscosity of the acrylamide copolymer. However, the effect of EASB‐1a was more prominent compared to that of EASB‐1b. The surfactant with a higher degree of ethoxylation showed lower adsorption compared to the surfactant with a lesser degree of ethoxylation. Both surfactants showed excellent foamability and foam stability compared to the commercial surfactants. Excellent thermal stability, water solubility under harsh reservoir conditions, foaming properties, and lower adsorption make them a suitable choice for high‐temperature, high‐salinity reservoirs.

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“…However, when PEs present opposite charges, electrostatic interactions are established between them. When phase separation occurs, a phase becomes enriched in the two polymers while the other is composed by solvent only [237] . Hence, phase separation results in macroscopic phase separation, or in polymeric complexes [238] .…”

Section: E-issn: 2321-6212 P-issn: 2347-2278mentioning

confidence: 99%

Chitosan/Poly(γ-glutamic acid) Polyelectrolyte Complexes: From Self- Assembly to Application in Biomolecules Delivery and Regenerative Medicine

Antunes¹,

Rm²,

Barbosa³

2016

Res. Rev. J Mat. Sci

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Research & Reviews: Journal of Material Sciences acids, binding strongly with negatively charged biomolecules, and useful for gene therapy [22][23][24][25] . Plus, as a cationic polymer, Ch can be combined with anionic polymers.Poly(γ-glutamic acid (γ-PGA) is one of the most promisor anionic PEs, highly due to its non-immunogenic behavior [26][27][28] and biodegradability into glutamic acid residues [29,30] . Glutamate is mostly known as major excitatory neurotransmitter in the central nervous system, acting as a synaptic transmitter, and influencing neuronal excitability, synaptic structure and function, neuronal migration during development, and neuronal viability [31][32][33][34][35] . It is also present in other tissues and organs, specifically in non-neuronal tissues like bone, pancreas, skin and cartilage [31,[33][34][35][36] , and having significant roles in their normal function, although yet not fully understood. γ-PGA, being a poly(amino acid) built by glutamic acid monomers [29,30,37,38] , may participate in similar processes.Ch/γ-PGA PECs appear to be promisor with an increasing number of references in the literature, but there is a lack of systematized information. Therefore, this review aims to overview the process of PEC formation within different architectures, as well as the current status of the Ch/γ-PGA PECs and their applications in the fields of drug delivery and regenerative medicine. Within this scope, we expect to identify the main challenges of Ch/γ-PGA PECs application for tissue regeneration. CHITOSAN (Ch) AND POLY(γ-GLUTAMIC ACID (γ-PGA) AS POLYELECTROLYTES (PEs)Polyelectrolyte (PE) is the term used to classify polymeric macromolecules with charged or chargeable groups when dissolved in polar solvents (predominantly water) [39,40] . When a PE dissociates, it gives rise to a macroion and counterions in aqueous solution [39] . The macroion can be named polycation (positively charged PE) or polyanion (negatively charged PE) [40] . Table 1 highlights some of the most studied PEs, either from natural or synthetic origin.

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Solution Properties of Partially Hydrolysed Polyacrylamide and Chitosan Mixed Solutions

Cited by 15 publications

References 27 publications

Prolonged mosquitocidal activity of Siparuna guianensis essential oil encapsulated in chitosan nanoparticles

Prolonged mosquitocidal activity of Siparuna guianensis essential oil encapsulated in chitosan nanoparticles

Development of Polyoxyethylene Zwitterionic Surfactants for High‐Salinity High‐Temperature Reservoirs

Chitosan/Poly(γ-glutamic acid) Polyelectrolyte Complexes: From Self- Assembly to Application in Biomolecules Delivery and Regenerative Medicine

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