Abstract
This thesis reports the preparation of chitosan/polyacrylamide/graphene oxide nanocomposites (CAGs) and a study of its adsorption properties of methylene blue (MB) solution. Initially, we synthesized CAGs by blending and freeze-drying methods. Then, we conducted a series experiments by removing MB from aqueous solution to test its adsorption properties and adsorption mechanism. We used UV-Vis spectrophotometry to determine the concentration of residual methylene blue accurately and efficiently, which has a specific absorption peak at 662 nm in the UV-Vis spectrum, in aqueous solution. When the graphene oxide content in the composite was 20 wt%, the adsorption capacity reached maximum values. The chemical properties and surface structure of the nanomaterials were analyzed using FT-IR, TGA, SEM, and BET. Also, we carried out experiments to measure the adsorption properties of the CAGs by varying several factors, such as initial concentration, adsorption time, and pH, etc. The outcomes revealed that the adsorption equilibrium was developed after 2800 min at 20 °C (room temperature) with an adsorbent dosage of 0.01 g mL−1. The ion adsorption equilibrium data were well-fitted by the Langmuir isotherm with a maximum monolayer capacity of 510.2 mg/g. Kinetic researches disclosed that the adsorption procedure was defined by a pseudo-second-order model. Thermodynamic researches revealed that the enthalpy change (ΔH 0) as well as Gibbs free energy change (ΔG 0) of the adsorption procedure was negative, indicating that the adsorption procedure was spontaneous and exothermic. After three cycles, the removal efficiency was still 90.18%. Therefore, in conclusion, we believe that the CAGs is a good adsorption material for organic dyes due to its good adsorption and recyclable properties.
Highlights
In recent years, along with progress of society and the development of technology, the change of the dye industry is huge
The diffraction peak related to C=O stretching vibration of amide group moved to chitosan/polyacrylamide/graphene oxide nanocomposites (CAGs) at 1665 cm−1
The synthesized CAG material, the characteristic peak corresponding to O-H at 3185 cm−1 is significantly broadened by the addition of graphene oxide (GO); and the characteristic peak corresponding to C=O
Summary
Along with progress of society and the development of technology, the change of the dye industry is huge. The GO contains a large amount of oxygen-containing functional groups, i.e., epoxy, hydroxyl as well as carbonyl [9] As a result, it will work well in many fields, such as DNA detection [10], cathodic protection [11,12], graphene transistors [13], and environmental protection, that can absorb the heavy metal ions and organic pollutants from polluted wastewater [14,15]. GO disperses well in water and requires a long time to separate from solution after adsorption, which limits its practical use To solve this problem, we have combined GO with other polymers or inorganic composites to form a composite material that can stabilize GO in water. It can play a good role in environmental protection
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
