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Babău T, Ciopec M, Duteanu N, Negrea A, Negrea P, Nemeş NS, Pascu B, Mihăilescu M, Ianasi C. Synthesis of Some Eco-Friendly Materials for Gold Recovery. Polymers (Basel) 2024; 16:2512. [PMID: 39274145 PMCID: PMC11398204 DOI: 10.3390/polym16172512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2024] [Revised: 08/15/2024] [Accepted: 08/26/2024] [Indexed: 09/16/2024] Open
Abstract
The aim of this study was to develop new materials with adsorbent properties that can be used for the adsorption recovery of Au(III) from aqueous solutions. To achieve this result, it is necessary to obtain inexpensive adsorbent materials in a granular form. Concomitantly, these materials must have a high adsorption capacity and selectivity. Other desired properties of these materials include a higher physical resistance, insolubility in water, and materials that can be regenerated or reused. Among the methods applied for the separation, purification, and preconcentration of platinum-group metal ions, adsorption is recognised as one of the most promising methods because of its simplicity, high efficiency, and wide availability. The studies were carried out using three supports: cellulose (CE), chitosan (Chi), and diatomea earth (Diat). These supports were functionalised by impregnation with extractants, using the ultrasound method. The extractants are environmentally friendly and relatively cheap amino acids, which contain in their structure pendant groups with nitrogen and sulphur heteroatoms (aspartic acid-Asp, l-glutamic acid-Glu, valine-Val, DL-cysteine-Cys, or serine-Ser). After preliminary testing from 75 synthesised materials, CE-Cys was chosen for the further recovery of Au(III) ions from aqueous solutions. To highlight the morphology and the functionalisation of the material, we physicochemically characterised the obtained material. Therefore, the analysis of the specific surface and porosity showed that the CE-Cys material has a specific surface of 4.6 m2/g, with a porosity of about 3 nm. The FT-IR analysis showed the presence, at a wavelength of 3340 cm-1, of the specific NH bond vibration for cysteine. At the same time, pHpZc was determined to be 2.8. The kinetic, thermodynamic, and equilibrium studies showed that the pseudo-second-order kinetic model best describes the adsorption process of Au(III) ions on the CE-Cys material. A maximum adsorption capacity of 12.18 mg per gram of the adsorbent material was achieved. It was established that the CE-Cys material can be reused five times with a good recovery degree.
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Affiliation(s)
- Theodora Babău
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timişoara, Victoriei Square, No. 2, 300006 Timisoara, Romania
| | - Mihaela Ciopec
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timişoara, Victoriei Square, No. 2, 300006 Timisoara, Romania
| | - Narcis Duteanu
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timişoara, Victoriei Square, No. 2, 300006 Timisoara, Romania
| | - Adina Negrea
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timişoara, Victoriei Square, No. 2, 300006 Timisoara, Romania
| | - Petru Negrea
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timişoara, Victoriei Square, No. 2, 300006 Timisoara, Romania
| | - Nicoleta Sorina Nemeş
- Renewable Energy Research Institute-ICER, Politehnica University of Timisoara, Gavril Musicescu Street, No. 138, 300774 Timisoara, Romania
| | - Bogdan Pascu
- Renewable Energy Research Institute-ICER, Politehnica University of Timisoara, Gavril Musicescu Street, No. 138, 300774 Timisoara, Romania
| | - Maria Mihăilescu
- Renewable Energy Research Institute-ICER, Politehnica University of Timisoara, Gavril Musicescu Street, No. 138, 300774 Timisoara, Romania
| | - Catalin Ianasi
- "Coriolan Drăgulescu" Institute of Chemistry, Bv. Mihai Viteazul, No. 24, 300223 Timisoara, Romania
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Jafri NF, Mohd Salleh K, Ahmad Ghazali N, Nyak Mazlan NS, Ab Halim NH, Zakaria S. Effects of carboxymethyl cellulose fiber formations with chitosan incorporation via coating and mixing processes. Int J Biol Macromol 2023; 253:126971. [PMID: 37729993 DOI: 10.1016/j.ijbiomac.2023.126971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/23/2023] [Accepted: 09/15/2023] [Indexed: 09/22/2023]
Abstract
To date, the utilization of carboxymethyl cellulose (CMC) fibers are only restricted to weak mechanical application such as wound dressing. Physically, CMC has a weak mechanical strength due to the high hydrophilicity trait. However, this flaw was saved by the extensive number of reactive functional groups, allowing this macromolecule to form linkages with chitosan to ensure its versatility. This work successfully fabricated CMC-chitosan fiber via dissolution, crosslinking, dry-jet wet-spinning extrusion, and coagulation processes. Chitosan was constituted with CMC fiber in two approaches, coating, and inclusion at various concentrations. Morphologically, chitosan incorporation has triggered agglomerations and roughness toward CMC fibers (CMCF). Chemically, the interaction between CMC and chitosan was proved through FTIR analysis at peaks 1245 cm-1 (ECH covalent crosslinking), while 3340 cm-1 and 1586 cm-1 were due to ionic and hydrogen bonding. The result from analysis showed that at higher chitosan concentrations, the chitosan-included CMC fiber (CMCF-I) and chitosan-coated CMC fiber (CMFC) were mechanically enhanced (up to 86.77 and 82.72 MPa), thermally more stable (33 % residual mass), and less hydrophilic compared to the plain CMCF. The properties of CMC-chitosan fibers have opened up vast possible applications, especially as a reinforcement in a watery medium such as a hydrogel.
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Affiliation(s)
- Nur Fathihah Jafri
- Bioresource and Biorefinery Laboratory, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Kushairi Mohd Salleh
- Bioresource Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang 11800, Malaysia; Renewable Biomass Transformation Cluster, School of Industrial Technology, Universiti Sains Malaysia, Penang 11800, Malaysia.
| | - Nursyamimi Ahmad Ghazali
- Bioresource and Biorefinery Laboratory, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Nyak Syazwani Nyak Mazlan
- Bioresource and Biorefinery Laboratory, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Nurul Husna Ab Halim
- Bioresource and Biorefinery Laboratory, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
| | - Sarani Zakaria
- Bioresource and Biorefinery Laboratory, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.
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Wang K, Shi Y, Li Z. Colorful Luminescence of Conjugated Polyelectrolytes Induced by Molecular Weight. Polymers (Basel) 2022; 14:5372. [PMID: 36559738 PMCID: PMC9785289 DOI: 10.3390/polym14245372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 12/13/2022] Open
Abstract
Due to their distinctive intrinsic advantages, the nanoaggregates of conjugated polyelectrolytes (CPEs) are fascinating and attractive for various luminescence applications. Generally, the emission luminescence of CPEs is determined by the conjugated backbone structure, i.e., different conjugated backbones of CPEs produce emission luminescence with different emission wavelength bands. Here, we polymerized the bis(boronic ester) of benzothiadiazole and an alkyl sulfonate sodium-substituted dibromobenzothiatriazole to provide PBTBTz-SO3Na with different molecular weights via controlling the ratio of the monomer and the catalyst. Theoretically, the CPEs with the same molecular structure usually display similar photoelectronic performances. However, the resulting PBTBTz-SO3Na reveal a similar light absorption property, but different luminescence. The higher molecular weight is, the stronger the fluorescence intensity of PBTBTz-SO3Na that occurs. PBTBTz-SO3Na with different molecular weights have different colors of luminescence. It is well known that the molecular aggregates often led to weaker luminescent properties for most of the conjugated polymers. However, PBTBTz-SO3Na exhibits a higher molecular weight with an increasing molecular chain aggregation, i.e., the nanoaggregates of PBTBTz-SO3Na are beneficial to emission luminescence. This work provides a new possible chemical design of CPEs with a controllable, variable luminescence for further optoelectronics and biomedicine applications.
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