Tuning electrostatic interactions for controlled structure and rejection of cellulose nanocrystal membranes

Date

2022-11-05

Author

Kocaman, Ceren
Büküşoğlu, Emre
Çulfaz Emecen, Pınar Zeynep

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

150
views

0
downloads

© 2022 Elsevier B.V.Precise control over membrane performance by tuning fabrication parameters is highly desirable. We developed ultrafiltration membranes by depositing cellulose nanocrystals (CNCs) on a porous support via tangential flow filtration, followed by irreversibly coagulating the deposited layer by permeating highly concentrated AlCl3 solution. By varying electrostatic interactions between nanocrystals during deposition, via varying ionic strength and pH of CNC suspensions, membrane performance was tuned. Increasing NaCl concentration of CNC suspensions from 0 to 50 mM increased Blue Dextran (5 kDa) rejection from 93% to 98.5% at high tangential flowrate and from 82% to 98% at low tangential flowrate. For membranes fabricated at high tangential flowrate, β-lactoglobulin (18 kDa) rejections increased from 94% to 98% when NaCl concentration increased from 0 to 25 mM. Increasing pH of CNC suspensions also increased probe molecule rejections, implying smaller interparticle distance between CNCs in the deposit layer. Pure water permeance of membranes were comparable to commercial membranes of similar separation properties. Polarized optical microscopy analyses showed that alignment of CNCs and their aggregates, or tactoids, affect the morphology of CNC deposits. In all cases, decreasing electrostatic repulsion between nanocyrstals increased rejection regardless of CNC alignment, which provides a simple parameter for tuning CNC membrane performance.

Subject Keywords

Cellulose nanocrystals, Controlled deposition, Electrostatic interactions, Shear alignment, Ultrafiltration

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85136268104&origin=inward
https://hdl.handle.net/11511/99219

Journal

Journal of Membrane Science

DOI

https://doi.org/10.1016/j.memsci.2022.120932

Collections

Department of Chemical Engineering, Article

Suggestions

OpenMETU
Core

PROCESSING CELLULOSE NANOCRYSTAL SUSPENSIONS FOR ALIGNED DEPOSITION Kocaman, Ceren; Bukusoglu, Emre; Çulfaz Emecen, Zeynep; Department of Chemical Engineering (2022-4-26) Precise control over membrane performance by tuning fabrication parameters is highly desirable. We developed ultrafiltration membranes by depositing cellulose nanocrystals (CNCs) of 180 nm length and 8 nm diameter on porous support via tangential flow filtration, then irreversibly coagulated the deposited layer permeating highly concentrated AlCl3 solution. At a high enough shear rate on the support surface, CNCs aligned in the flow direction, showing a nematic order. The shear rates for transition to the n...
Applications of simulated annealing for the design of special digital filters - Comments Çiloğlu, Tolga; Ünver, Zafer (1996-04-01) The way of measuring the performance of a discrete coefficient filter which is designed by scaling optimization is discussed.
Real-Time Detection of Interharmonics and Harmonics of AC Electric Arc Furnaces on GPU Framework Uz-Logoglu, Eda; Salor, Ozgul; Ermiş, Muammer (2019-11-01) In this paper, a method based on the multiple synchronous reference frame analysis is recommended and implemented to detect time-varying harmonics and interharmonics of rapidly fluctuating asymmetrical industrial loads. The experimental work has been carried out on a typical three-phase alternating current arc furnace installation. In the recommended method, the reference frame is rotated in both directions at speeds corresponding to the positive and negative sequences of all harmonics and all interharmonic...
Optimization of Power Conversion Efficiency in Threshold Self-Compensated UHF Rectifiers With Charge Conservation Principle Gharehbaghi, Kaveh; KOÇER, FATİH; Külah, Haluk (2017-09-01) This paper presents a compact model for threshold self-compensated rectifiers that can be used to optimize circuit parameters early in the design phase instead of time-consuming transient simulations. A design procedure is presented for finding the optimum aspect ratio of transistors used in the converter and number of rectifying stages to achieve the maximum power conversion efficiency. In the presented analysis, the relation between the power conversion efficiency and the load current over the variation o...
Site Specific Relationship for Strain Dependent Shear Modulus and Damping Using In Situ V S and High Strain Cyclic Test Results Zehtab, Kaveh Hassan; Yılmaz, Mustafa Tolga (2016-08-18) This study suggests a practical method for estimating site-specific strain dependent shear modulus and damping. The method uses in-situ shear wave velocity measurements and commercial cyclic laboratory tests on higher strains (i.e., 0.5% to 1%) in which the effect of disturbance is less significant. Shear modulus calculated using in-situ shear wave velocity and at higher cyclic shear strain, is used for building a hyperbolic relationship for shear stress and strain. Modified Masing's rule and the experiment...

Citation Formats

C. Kocaman, E. Büküşoğlu, and P. Z. Çulfaz Emecen, “Tuning electrostatic interactions for controlled structure and rejection of cellulose nanocrystal membranes,” Journal of Membrane Science, vol. 661, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85136268104&origin=inward.