Vapour and Solution Uptake Properties of Starch and Cellulose Biopolymers

Dehabadi, Leila; Shakouri, Mohsen; Simonson, Carey J.; Arjmand, Mohammad; Sundararaj, Uttandaraman; Wilson, Lee D.

doi:10.4236/gep.2018.65009

Cited by 4 publications

(3 citation statements)

References 36 publications

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“…A dye-based SA calculation was used to evaluate the textural properties of the adsorbents in their hydrated form [58]. The surface area of CS-Ac-An in the FL solution was calculated 40.2 m 2 g −1 at ambient pH using Equation (4).…”

Section: Surface Area (Sa)mentioning

confidence: 99%

Surface-Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein

Vafakish

Wilson

2019

Surfaces

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Tweezer-like adsorbents with enhanced surface area were synthesized by grafting aniline onto the amine sites of a chitosan biopolymer scaffold. The chemical structure and textural properties of the adsorbents were characterized by thermogravimetric analysis (TGA) and spectral methods, including Fourier transform infrared (FT-IR), nuclear magnetic resonance (1H- and, 13C-NMR) and scanning electron microscopy (SEM). Equilibrium solvent swelling results for the adsorbent materials provided evidence of a more apolar biopolymer surface upon grafting. Equilibrium uptake studies with fluorescein at ambient pH in aqueous media reveal a high monolayer adsorption capacity (Qm) of 61.8 mg·g−1, according to the Langmuir isotherm model. The kinetic adsorption profiles are described by the pseudo-first order kinetic model. 1D NMR and 2D-NOESY NMR spectra were used to confirm the role of π-π interactions between the adsorbent and adsorbate. Surface modification of the adsorbent using monomeric and dimeric cationic surfactants with long hydrocarbon chains altered the hydrophile-lipophile balance (HLB) of the adsorbent surface, which resulted in attenuated uptake of fluorescein by the chitosan molecular tweezers. This research contributes to a first example of the uptake properties for a tweezer-like chitosan adsorbent and the key role of weak cooperative interactions in controlled adsorption of a model anionic dye.

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Section: Surface Area (Sa)mentioning

confidence: 99%

Surface-Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein

Vafakish

Wilson

2019

Surfaces

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“…By contrast, the longevity of SPs was improved for SP-CPB0.5, as evidenced by the enhanced antimicrobial activity of CPB toward a range of bacterial strains, as compared with unmodified SPs . The aim of this paper is to further our research efforts toward new biopolymer desiccants − with improved sorption capacity, adsorption/desorption regeneration, and temporal stability by testing surfactant-coated SPs. Herein, SP-CPB0.5 (surfactant concentration = 0.5 mM) was selected based on a previous optimization study.…”

Section: Introductionmentioning

confidence: 99%

Water Vapor Adsorption–Desorption Behavior of Surfactant-Coated Starch Particles for Commercial Energy Wheels

et al. 2019

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This study reports on the adsorption (dehumidification)–desorption (humidification) behavior of cetylpyridinium bromide (CPB) coated starch particles (SPs), denoted as SP-CPB, as a potential desiccant material for air-to-air energy exchangers. CPB is a cationic surfactant with antibacterial activity that can be used to modify the surface properties of SPs, especially at variable CPB loading levels (SP-CPB0.5, SP-CPB2.5, and SP-CPB5.0, where the numeric suffix represents the synthetic loading level of CPB in mM). The SP-CPB0.5 sample displayed optimal surface area and pore structure properties that was selected for water sorption isotherm studies at 25 °C. The CPB-coated SPs sample (SP-CPB0.5) showed an improved water vapor uptake capacity compared to unmodified starch (SPs) and other desiccant systems such as high amylose starch (HAS15) and silica gel (SG13). Single-step and cyclic water vapor sorption tests were conducted using a small-scale exchanger coated with SP-CPB0.5. The calculated latent effectiveness values obtained from direct measurements using cyclic tests (65.4 ± 2%) agree closely with the estimated latent effectiveness from single-step tests (64.6 ± 2%) at controlled operating conditions. Compared to HAS15- and SG13-coated exchangers, the SP-CPB0.5-coated exchanger performed much better at controlled operating conditions, along with improved longevity due to the CPB surface coating. The presence of CPB did not attenuate the uptake properties of native SPs. Latent effectiveness of SP-CPB0.5-coated exchanger was enhanced (5–30% higher) over that of the SG13- or HAS15-coated exchangers, according to the wheel angular speed. This study reports on a novel and sustainable SP-CPB0.5 material as a promising desiccant coating with tunable uptake and surface properties with potential utility in air-to-air energy exchangers for ventilation systems.

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“…The disparity in the swelling, recyclability, and moisture sorption/desorption rates relates to various factors: (i) the relative composition of the AM/AP within the starches; (ii) the pore structures of the copolymers; and (iii) the propensity of the copolymer networks to swell in water. Generally, starch materials with a higher AM content show greater water uptake properties due to their hydrophilic character, conformational motility, and relative access of donor-acceptor sites [ 134 ]. This is further evidenced for the swelling/recyclability rates and water absorption values for the copolymers of IRS-AA with 24%/50% AM/AP contents (cf.…”

Section: Demonstrating the Water Uptake Characteristics Of Hydrogementioning

confidence: 99%

A Review on the Design and Hydration Properties of Natural Polymer-Based Hydrogels

2021

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Hydrogels are hydrophilic 3D networks that are able to ingest large amounts of water or biological fluids, and are potential candidates for biosensors, drug delivery vectors, energy harvester devices, and carriers or matrices for cells in tissue engineering. Natural polymers, e.g., cellulose, chitosan and starch, have excellent properties that afford fabrication of advanced hydrogel materials for biomedical applications: biodegradability, biocompatibility, non-toxicity, hydrophilicity, thermal and chemical stability, and the high capacity for swelling induced by facile synthetic modification, among other physicochemical properties. Hydrogels require variable time to reach an equilibrium swelling due to the variable diffusion rates of water sorption, capillary action, and other modalities. In this study, the nature, transport kinetics, and the role of water in the formation and structural stability of various types of hydrogels comprised of natural polymers are reviewed. Since water is an integral part of hydrogels that constitute a substantive portion of its composition, there is a need to obtain an improved understanding of the role of hydration in the structure, degree of swelling and the mechanical stability of such biomaterial hydrogels. The capacity of the polymer chains to swell in an aqueous solvent can be expressed by the rubber elasticity theory and other thermodynamic contributions; whereas the rate of water diffusion can be driven either by concentration gradient or chemical potential. An overview of fabrication strategies for various types of hydrogels is presented as well as their responsiveness to external stimuli, along with their potential utility in diverse and novel applications. This review aims to shed light on the role of hydration to the structure and function of hydrogels. In turn, this review will further contribute to the development of advanced materials, such as “injectable hydrogels” and super-adsorbents for applications in the field of environmental science and biomedicine.

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Vapour and Solution Uptake Properties of Starch and Cellulose Biopolymers

Cited by 4 publications

References 36 publications

Surface-Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein

Surface-Modified Chitosan: An Adsorption Study of a “Tweezer-Like” Biopolymer with Fluorescein

Water Vapor Adsorption–Desorption Behavior of Surfactant-Coated Starch Particles for Commercial Energy Wheels

A Review on the Design and Hydration Properties of Natural Polymer-Based Hydrogels

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