Charge Density Quantification of Polyelectrolyte Polysaccharides by Conductometric Titration: An Analytical Chemistry Experiment

Farris, Stefano; Mora, Luigi; Capretti, G.; Piergiovanni, Luciano

doi:10.1021/ed200261w

Cited by 28 publications

(26 citation statements)

References 12 publications

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“…The charge density (mmol g −1 ) can be determined by multiplying the value of the concentration (normality) by the volume of HCl (mL) required to fully protonate all carboxylic groups of SA (Table ) . The results demonstrate that, on increasing the SA concentration in the continuous phase, the charge density increases.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and in situ functionalization of microfiltration membranes via high internal phase emulsion templating

Malakian

Zhou

Zowada

et al. 2019

Polymer International

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The continuous phase of high internal phase emulsions (HIPEs) can be polymerized to produce highly porous materials, known as polyHIPEs. The aim of this work was to synthesize polyHIPE microfiltration membranes having a hydrophobic bulk and a hydrophilic surface to enhance their performance. Therefore, in situ functionalization was performed through interfacial copolymerization of a hydrophobic monomer (butyl acrylate) in the continuous phase with a hydrophilic monomer (sodium acrylate) in the disperse phase. The functionalization of polyHIPEs was studied by using conductometric titration and Fourier transform IR spectroscopy. We show that the surface charge density of poly(butyl acrylate)-based polyHIPEs can be controlled by varying the concentration of sodium acrylate in the disperse phase. PolyHIPE microfiltration membranes have higher intrinsic permeability (around 1.31 × 10 −8 m 2 ) in comparison to conventional microfiltration membranes. The interfacial copolymerization of sodium acrylate increases the permeability of microfiltration membranes. In addition, the rejection of polyHIPE microfiltration membranes was studied for the separation of microalgae. Characterization techniques Scanning electron microscopyThe morphology of the polyHIPEs was studied via a scanning electron microscope (S-3400N Type II, Hitachi High-Technologies Corp.). The samples were fractured in liquid nitrogen and sputter Polym Int 2019; 68: 1378-1386

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Section: Resultsmentioning

confidence: 99%

Synthesis and in situ functionalization of microfiltration membranes via high internal phase emulsion templating

Malakian

Zhou

Zowada

et al. 2019

Polymer International

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“…The charge density of MFC was determined by conductometric titration following the method described in a previous study [50]. Briefly, a MFC aqueous dispersion (0.1 wt.%) was As the conductance decreased and the first equivalence point was approached, drops of 0.05 mL at a 0.15 μL s -1 flow rate were dispensed, while the initial set-up conditions were brought back beyond the constant-conductivity region.…”

Section: Conductometric Titrationmentioning

confidence: 99%

Exploiting the nano-sized features of microfibrillated cellulose (MFC) for the development of controlled-release packaging

Cozzolino

Nilsson

Iotti

et al. 2013

Colloids and Surfaces B: Biointerfaces

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Microfibrillated cellulose (MFC) was used in this study to prepare films containing an active molecule, lysozyme, which is a natural antimicrobial agent. The main goal of this research was to assess the potential for exploiting the nano-sized dimension of cellulose fibrils to slow the release of the antimicrobial molecule, thus avoiding a too-quick release into the surrounding medium, which is a major disadvantage of most release systems. For this purpose, the release kinetics of lysozyme over a 10-day period in two different media (pure water and water/ethanol 10wt.%) were obtained, and the experimental data was fitted with a solution of Fick's second law to quantify the apparent diffusion coefficient (D). The results indicate that the MFC retained lysozyme, presumably due to electrostatic, hydrogen, and ion-dipole interactions, with the largest release of lysozyme-approximately 14%-occurring from the initial amount loaded on the films. As expected, ethanol as a co-solvent slightly decreased the diffusion of lysozyme from the MFC polymer network. The addition of two potential modulating release agents-glycerol and sodium chloride-was also evaluated. Findings from this work suggest that MFC-based films can be considered a suitable candidate for use in controlled-release packaging systems.

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“…The DA of the soluble chitin fractions was determined by conductometric titration as reported by Farris et al . For this, the volume of the 0.1 N HCl titrant used to achieve the protonation of the free amino groups of the chitin molecule was determined.…”

Section: Methodsmentioning

confidence: 99%

Enzymatic treatments as alternative to produce chitin fragments of low molecular weight from Alternaria alternata

García

Troncoso‐Rojas

Tiznado‐Hernández

et al. 2018

J of Applied Polymer Sci

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Chitin and its oligosaccharides are involved in the plant defense response against fungal pathogens. In most studies, these molecules come from crustacean shell, and there are scarce studies on the use of fungal chitin. Usually the extraction of chitin is by alkaline treatments, which affect the acetylation degree (DA), and the obtaining of oligosaccharides of low molecular weight; so the use of enzymes is proposed as an alternative treatment to obtain chitin oligosaccharides from fungi. The objective of this work was to characterize the chitin fragments of Alternaria alternata extracted by alkaline and enzymatic treatments. The chitin extracted was ultrasonicated and ultrafiltrated to produce chitin fragments. Enzymatic treatments decreased the protein content to 29%, and the bands corresponding to β‐glucans decreased when β‐1,3‐glucanase was applied. Fragments smaller than 1 kDa, DA of 76.7%, and 35.4 μg glucosamine/mg dry weight were obtained by enzymatic treatments. The enzymatic treatments show promising results to extract chitin fragments from A. alternata without severely affect the DA of the molecule. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47339.

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Charge Density Quantification of Polyelectrolyte Polysaccharides by Conductometric Titration: An Analytical Chemistry Experiment

Cited by 28 publications

References 12 publications

Synthesis and in situ functionalization of microfiltration membranes via high internal phase emulsion templating

Synthesis and in situ functionalization of microfiltration membranes via high internal phase emulsion templating

Exploiting the nano-sized features of microfibrillated cellulose (MFC) for the development of controlled-release packaging

Enzymatic treatments as alternative to produce chitin fragments of low molecular weight from Alternaria alternata

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