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Keywords = cationic pullulan derivatives

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17 pages, 4571 KB  
Article
Cationic Pullulan Derivatives Based Flocculants for Removal of Some Metal Oxides from Simulated Wastewater
by Luminita Ghimici, Maria Magdalena Nafureanu and Marieta Constantin
Int. J. Mol. Sci. 2023, 24(5), 4383; https://doi.org/10.3390/ijms24054383 - 23 Feb 2023
Cited by 9 | Viewed by 2502
Abstract
Modified polysaccharides have been increasingly used as flocculants in wastewater treatment due to their non-toxicity, low price, biodegradability, etc. However, the pullulan derivatives are less used in wastewater purification processes. Therefore, this article presents some data regarding FeO and TiO2 particle removal [...] Read more.
Modified polysaccharides have been increasingly used as flocculants in wastewater treatment due to their non-toxicity, low price, biodegradability, etc. However, the pullulan derivatives are less used in wastewater purification processes. Therefore, this article presents some data regarding FeO and TiO2 particle removal from model suspensions by some pullulan derivatives with pendant quaternary ammonium salt groups, trimethylammonium propyl carbamate chloride (TMAPx–P). The influence of the polymer ionic content, dose, and initial solution concentration as well as of the dispersion pH and composition (metal oxide content, salts, and kaolin) on the separation efficacy were considered. UV-Vis spectroscopy measurements have shown a very good removal efficacy of TMAPx–P for the FeO particles (around 95% and more), irrespective of the polymer and suspension characteristics; a lower clarification of the TiO2 particles suspension (removal efficiency between 68% and 75%) was noticed. Both the zeta potential and the particle aggregates size measurements revealed the charge patch as the main mechanism which governs the metal oxide removal process. The surface morphology analysis/EDX data provided supplementary evidence regarding the separation process. A good removal efficiency (90%) of the pullulan derivatives/FeO flocs for the Bordeaux mixture particles from simulated wastewater was found. Full article
(This article belongs to the Special Issue Biomaterials for Pollutants Removal: From Molecular Perspectives)
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13 pages, 4183 KB  
Article
Grafted Pullulan Derivatives for Reducing the Content of Some Pesticides from Simulated Wastewater
by Luminita Ghimici, Marieta Constantin and Maria-Magdalena Nafureanu
Polymers 2022, 14(13), 2663; https://doi.org/10.3390/polym14132663 - 29 Jun 2022
Cited by 2 | Viewed by 2231
Abstract
The goal of the current article was to obtain data regarding the application of a series of grafted pullulan derivatives, as flocculating agents, for removal of some pesticide formulations from model wastewater. The pullulan derivatives are cationic polyelectrolytes, with various content and length [...] Read more.
The goal of the current article was to obtain data regarding the application of a series of grafted pullulan derivatives, as flocculating agents, for removal of some pesticide formulations from model wastewater. The pullulan derivatives are cationic polyelectrolytes, with various content and length of grafted poly[(3-acrylamidopropyl)-trimethylammonium chloride] chains onto the pullulan (P-g-pAPTAC)]. The commercial pesticides are either fungicide (Bordeaux Mixture) (BM) or insecticides (Decis (Dc)—active ingredient Deltamethrin, Confidor Oil (CO)—active ingredient Imidacloprid, Confidor Energy (CE)—active ingredients Deltamethrin and Imidacloprid and Novadim Progress (NP)—active ingredient Dimethoate). The removal efficiency has been assessed by UV-Vis spectroscopy measurements as a function of some parameters, namely polymer dose, grafted chains content and length, pesticides concentration. The P-g-pAPTAC samples showed good removal efficacy at doseop, more than 94% for BM, between 84 and 90% for DC, CO and CE and around 93% for NP. The maximum percentage removal decreased with the pesticides (DC, CO, CE, NP) concentration declining; no effect of BM concentration in suspension on its removal efficiency process has been noted. Differences indicated by zeta potential and particle size distribution measurements regarding the pesticides removal mechanisms by pullulan derivatives (charge neutralization, bridging, etc.) are discussed. Full article
(This article belongs to the Special Issue Natural Polysaccharide: Synthesis, Modification and Application)
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16 pages, 14014 KB  
Article
Nanohydrogels Based on Self-Assembly of Cationic Pullulan and Anionic Dextran Derivatives for Efficient Delivery of Piroxicam
by Dorota Lachowicz, Przemyslaw Mielczarek, Roma Wirecka, Katarzyna Berent, Anna Karewicz, Michał Szuwarzyński and Szczepan Zapotoczny
Pharmaceutics 2019, 11(12), 622; https://doi.org/10.3390/pharmaceutics11120622 - 21 Nov 2019
Cited by 11 | Viewed by 4964
Abstract
A cationic derivative of pullulan was obtained by grafting reaction and used together with dextran sulfate to form polysaccharide-based nanohydrogel cross-linked via electrostatic interactions between polyions. Due to the polycation-polyanion interactions nanohydrogel particles were formed instantly and spontaneously in water. The nanoparticles were [...] Read more.
A cationic derivative of pullulan was obtained by grafting reaction and used together with dextran sulfate to form polysaccharide-based nanohydrogel cross-linked via electrostatic interactions between polyions. Due to the polycation-polyanion interactions nanohydrogel particles were formed instantly and spontaneously in water. The nanoparticles were colloidally stable and their size and surface charge could be controlled by the polycation/polyanion ratio. The morphology of the obtained particles was visualized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The resulting structures were spherical, with hydrodynamic diameters in the range of 100–150 nm. The binding constant (Ka) of a model drug, piroxicam, to the cationic pullulan (C-PUL) was determined by spectrophotometric measurements. The value of Ka was calculated according to the Benesi—Hildebrand equation to be (3.6 ± 0.2) × 103 M−1. After binding to cationic pullulan, piroxicam was effectively entrapped inside the nanohydrogel particles and released in a controlled way. The obtained system was efficiently taken up by cells and was shown to be biocompatible. Full article
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