Thermally conductive polyethylene/expanded graphite composites as heat transfer surface: Mechanical, thermo-physical and surface behavior
Author | Sobolčiak, Patrik |
Author | Abdulgader, Asma |
Author | Mrlik, Miroslav |
Author | Popelka, Anton |
Author | A. Abdala, Ahmed |
Author | A. Aboukhlewa, Abdelnasser |
Author | Karkri, Mustapha |
Author | Kiepfer, Hendrik |
Author | Bart, Hans-Jörg |
Author | Krupa, Igor |
Available date | 2023-06-26T04:54:19Z |
Publication Date | 2020 |
Publication Name | Polymers |
Resource | Scopus |
Abstract | Composites of high-density polyethylene (HDPE) and expanded graphite (EG) are prepared for heat exchangers in multi-effect distillation (MED) desalination. At 50 wt.% EG loading, the thermal conductivity of HDPE was increased by 372%. Moreover, the surface wettability of the HDPE/EG composite was enhanced by corona and RF plasma treatment as demonstrated by the increase in surface free energy from 28.5 mJ/m2 for untreated HDPE/EG to 55.5 and 54.5 mJ/m2 for HDPE/EG treated by corona and RF plasma, respectively. This enhanced surface wettability was retained over a long time with only a 9% and 18% decrease in RF and corona plasma-treated samples' surface energy after two months. The viscoelastic moduli and the complex viscosity profiles indicated that EG content dictates the optimum processing technique. At loading below 30 wt.%, the extrusion process is preferred, while above 30 wt.% loading, injection molding is preferred. The plasma treatment also improved the HDPE/EG composite overall heat transfer coefficient with an overall heat transfer coefficient of the composite reaching about 98% that of stainless steel. Moreover, the plasma-treated composite exhibited superior resistance to crystallization fouling in both CaSO4 solution and artificial seawater compared to untreated composites and stainless-steel surfaces. |
Sponsor | Funding: This work was made possible by NPRP grant No.: NPRP10-0205-170349 from the Qatar National Research Fund (A Member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors. Acknowledgments: SEM was accomplished in the Central Laboratories unit, Qatar University. Author M.M.gratefully acknowledge the Ministry of Education, Youth and Sports of the Czech Republic-DKRVO (RP/CPS/2020/003). |
Language | en |
Publisher | MDPI AG |
Subject | Expanded graphite High density polyethylene Multi-effect distillation Plasma treatment Polymeric composites Scaling |
Type | Article |
Pagination | 1-19 |
Issue Number | 12 |
Volume Number | 12 |
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