scholarly journals Gas and Solution Uptake Properties of Graphene Oxide-Based Composite Materials: Organic vs. Inorganic Cross-Linkers

2019 ◽  
Vol 3 (3) ◽  
pp. 80 ◽  
Author(s):  
Sabzevari ◽  
Cree ◽  
Wilson
Keyword(s):  
Graphene Oxide ◽  
Zeta Potential ◽  
Electrostatic Interactions ◽  
Gas Adsorption ◽  
Aqueous Media ◽  
Adsorption Properties ◽  
Cross Linking ◽  
Supporting Evidence ◽  
Monolayer Adsorption ◽  
Adsorption Processes

This study focused on a comparison of the adsorption properties of graphene oxide (GO) and its composites that were prepared via cross-linking with chitosan (CTS) or Al3+ species, respectively. Comparative material characterization was achieved by several complementary methods: SEM, NMR spectroscopy, zeta-potential, dye-based adsorption, and gas adsorption at equilibrium and dynamic conditions. SEM, solids NMR, and zeta-potential results provided supporting evidence for cross-linking between GO and the respective cross-linker units. The zeta-potential of GO composites decreased upon cross-linking due to electrostatic interactions and charge neutralization. Equilibrium and kinetic adsorption profiles of the GO composites with methylene blue (MB) in aqueous media revealed superior uptake over pristine GO. The monolayer adsorption capacity (mg g−1) of MB are listed in descending order for each material: GO–CTS (408.6) > GO–Al (351.4) > GO (267.1). The gas adsorption results showed parallel trends, where the surface area and pore structure of the composites exceeded that for GO due to pillaring effects upon cross-linking. The green strategy reported herein for the preparation of tunable GO-based composites revealed versatile adsorption properties for diverse heterogeneous adsorption processes.

scholarly journals Uptake of Methylene Blue from Aqueous Solution by Pectin–Chitosan Binary Composites

2020 ◽  
Vol 4 (3) ◽  
pp. 95
Author(s):  
Dexu Kong ◽  
Lee D. Wilson
Keyword(s):  
Methylene Blue ◽  
Aqueous Media ◽  
Dye Adsorption ◽  
Adsorption Properties ◽  
Point Of Zero Charge ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Adsorption Sites ◽  
Biopolymer Composites

To address the need to develop improved hybrid biopolymer composites, we report on the preparation of composites that contain chitosan and pectin biopolymers with tunable adsorption properties. Binary biopolymer composites were prepared at variable pectin–chitosan composition in a solvent directed synthesis, dimethyl sulfoxide (DMSO) versus water. The materials were characterized using complementary methods (infrared spectroscopy, thermal gravimetric analysis, pH at the point-of-zero charge, and dye-based adsorption isotherms). Pectin and chitosan composites prepared in DMSO yielded a covalent biopolymer framework (CBF), whereas a polyelectrolyte complex (PEC) was formed in water. The materials characterization provided support that cross-linking occurs between amine groups of chitosan and the –COOH groups of pectin. CBF-based composites had a greater uptake of methylene blue (MB) dye over the PEC-based composites. Composites prepared in DMSO were inferred to have secondary adsorption sites for enhanced MB uptake, as evidenced by a monolayer uptake capacity that exceeded the pectin–chitosan PECs by 1.5-fold. This work provides insight on the role of solvent-dependent cross-linking of pectin and chitosan biopolymers. Sonication-assisted reactions in DMSO favor CBFs, while cross-linking in water yields PECs. Herein, composites with tunable structures and variable physicochemical properties are demonstrated by their unique dye adsorption properties in aqueous media.

Graphene oxide derived carbons (GODCs): synthesis and gas adsorption properties

2012 ◽  
Vol 5 (4) ◽  
pp. 6453 ◽  
Author(s):  
Gadipelli Srinivas ◽  
Jacob Burress ◽  
Taner Yildirim
Keyword(s):  
Graphene Oxide ◽  
Gas Adsorption ◽  
Adsorption Properties

Self-assembly of graphene oxide aerogels by layered double hydroxides cross-linking and their application in water purification

2014 ◽  
Vol 2 (23) ◽  
pp. 8941-8951 ◽  
Author(s):  
Qile Fang ◽  
Baoliang Chen
Keyword(s):  
Graphene Oxide ◽  
Structural Stability ◽  
Water Purification ◽  
Layered Double Hydroxides ◽  
Self Assembly ◽  
Adsorption Properties ◽  
The Self ◽  
Cross Linking ◽  
Double Hydroxides

3D macrostructural aerogels were synthesized based on the self-assembly of graphene oxide and LDHs, which exhibited excellent hydrophilicity, structural stability, and superior adsorption properties in water purification.

Assemblies of single-walled carbon nanotubes generated by covalent cross-linking with organic linkers

2015 ◽  
Vol 3 (13) ◽  
pp. 6747-6750 ◽  
Author(s):  
Ram Kumar ◽  
C. N. R. Rao
Keyword(s):  
Carbon Nanotubes ◽  
Gas Adsorption ◽  
Single Walled Carbon Nanotubes ◽  
Adsorption Properties ◽  
Cross Linking ◽  
Single Walled Carbon ◽  
Covalently Linked ◽  
Walled Carbon Nanotubes

Assemblies of covalently linked single-walled carbon nanotubes with superior gas adsorption properties have been prepared and characterized.

Understanding gas adsorption in MOF-5/graphene oxide composite materials

2017 ◽  
Vol 19 (18) ◽  
pp. 11639-11644 ◽  
Author(s):  
Li-Chiang Lin ◽  
Dooam Paik ◽  
Jihan Kim
Keyword(s):  
Graphene Oxide ◽  
Composite Materials ◽  
Gas Adsorption ◽  
Metal Organic Framework ◽  
Adsorption Properties ◽  
Oxide Composite ◽  
Metal Organic ◽  
Enhanced Adsorption ◽  
Organic Framework

Metal–organic framework (MOF) and graphene oxide (GO) composite materials (MOF/GO) have been regarded as promising for separation applications due to their synergistically enhanced adsorption properties.

Preparation of Graphene Oxide/Chitosan Pellets and Their Adsorption Properties for Congo Red

2019 ◽  
Vol 18 (05) ◽  
pp. 1850030 ◽  
Author(s):  
Qiuju Du ◽  
Yanhui Li ◽  
Jiabin Li ◽  
Zhao Zhang ◽  
Bin Qiao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Congo Red ◽  
Electrostatic Interactions ◽  
Kinetic Studies ◽  
Adsorption Properties ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Freundlich Model ◽  
Adsorption Data ◽  
Pseudo Second Order

A facile and easily separated adsorbent, graphene oxide (GO) pellets wrapped by chitosan (GOP) were prepared. Batch adsorption studies were carried out to study the adsorption properties of congo red onto GOP by varying the experimental parameters such as the contact time, the initial concentration of congo red, the solution pH, the adsorbent dose, and the temperature. The kinetic studies showed that the adsorption data fitted a pseudo-second-order model well. The isotherm analysis showed that the adsorption data fitted the Freundlich model well. The adsorption mechanism was mainly attributed to electrostatic interactions, [Formula: see text]–[Formula: see text] stacking interaction, hydrogen bond, and van der Waals force. Thermodynamic studies indicated that the adsorption process was endothermic and spontaneous.

scholarly journals Hyperbranched polyamide modified graphene oxide-reinforced polyurethane nanocomposites with enhanced mechanical properties

RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14484-14494
Author(s):  
Yahao Liu ◽  
Jian Zheng ◽  
Xiao Zhang ◽  
Yongqiang Du ◽  
Guibo Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
High Performance ◽  
Cross Linking ◽  
Elongation At Break ◽  
Modified Graphene Oxide ◽  
High Performance Composite ◽  
Modified Graphene ◽  
Polyurethane Nanocomposites ◽  
Hyperbranched Polyamide

We successfully modified graphene oxide with amino-terminated hyperbranched polyamide (HGO), and obtained a high-performance composite with enhanced strength and elongation at break via cross-linking hydroxyl-terminated polybutadiene chains with HGO.

scholarly journals Gas Porosimetry by Gas Adsorption as an Efficient Tool for the Assessment of the Shaping Effect in Commercial Zeolites

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1205
Author(s):  
Alejandro Orsikowsky-Sanchez ◽  
Christine Franke ◽  
Alexander Sachse ◽  
Eric Ferrage ◽  
Sabine Petit ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Strong Interaction ◽  
Gas Adsorption ◽  
Co2 Adsorption ◽  
Adsorption Properties ◽  
Preparation Process ◽  
Pore Filling ◽  
Irreversible Adsorption ◽  
Efficient Tool ◽  
4A Zeolite

A set of three commercial zeolites (13X, 5A, and 4A) of two distinct shapes have been characterized: (i) pure zeolite powders and (ii) extruded spherical beads composed of pure zeolite powders and an unknown amount of binder used during their preparation process. The coupling of gas porosimetry experiments using argon at 87 K and CO2 at 273 K allowed determining both the amount of the binder and its effect on adsorption properties. It was evidenced that the beads contain approximately 25 wt% of binder. Moreover, from CO2 adsorption experiments at 273 K, it could be inferred that the binder present in both 13X and 5A zeolites does not interact with the probe molecule. However, for the 4A zeolite, pore filling pressures were shifted and strong interaction with CO2 was observed leading to irreversible adsorption of the probe. These results have been compared to XRD, IR spectroscopy, and ICP-AES analysis. The effect of the binder in shaped zeolite bodies can thus have a crucial impact on applications in adsorption and catalysis.

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