Processing and properties of a graphene-reinforced superhydrophobic siloxane
Three-dimensional superhydrophobic materials are characterized by a low surface energy and extremely low strength, and hence require reinforcement for viable applications. An experimental study is presented of the processing and mechanical properties of a graphene-reinforced superhydrophobic siloxan...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-05-01
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| Series: | Materials & Design |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S026412752300271X |
| _version_ | 1797851336404893696 |
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| author | Li He Dongfang Wang Tiantian Ma Jinliang Song Yongkang Wu Yucheng Li Yongfeng Deng Guoping Zhang |
| author_facet | Li He Dongfang Wang Tiantian Ma Jinliang Song Yongkang Wu Yucheng Li Yongfeng Deng Guoping Zhang |
| author_sort | Li He |
| collection | DOAJ |
| description | Three-dimensional superhydrophobic materials are characterized by a low surface energy and extremely low strength, and hence require reinforcement for viable applications. An experimental study is presented of the processing and mechanical properties of a graphene-reinforced superhydrophobic siloxane, synthesized by a sol–gel approach integrating alkali activation of metakaolin, hydrolysis of alkoxysilane, dispersion of graphene into the precursor, and co-condensation. To promote uniform dispersion and distribution of graphene, three processing techniques were used: while ultrasonication was adopted to disperse graphene nanoplatelets, accelerated condensation at 50 and 75 °C and varying the precursor’s viscosity used to prevent graphene from floating and re-aggregation. Results of nanoindentation, porosimetry, and unconfined compression show that adding 0.9 wt% graphene increases the strength of the superhydrophobic composites from ∼ 0 to 34 MPa. Slow condensation and curing at 25 °C allow graphene to re-aggregate and float upward in the sol, leading to its heterogeneous distribution. Despite its function in improving microscale dispersion, ultrasonication detrimentally decreases the composite’s strength due to acoustic cavitation. Similarly, curing at elevated temperatures accelerates co-condensation and results in a more uniform distribution of graphene, but induces thermal cavitation and bubble formation, because the threshold for acoustic and thermal cavitations is significantly reduced by superhydrophobicity. |
| first_indexed | 2024-04-09T19:16:15Z |
| format | Article |
| id | doaj.art-e53f286c9c784ceb8ae44f70a1771a5f |
| institution | Directory Open Access Journal |
| issn | 0264-1275 |
| language | English |
| last_indexed | 2024-04-09T19:16:15Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj.art-e53f286c9c784ceb8ae44f70a1771a5f2023-04-06T06:10:15ZengElsevierMaterials & Design0264-12752023-05-01229111856Processing and properties of a graphene-reinforced superhydrophobic siloxaneLi He0Dongfang Wang1Tiantian Ma2Jinliang Song3Yongkang Wu4Yucheng Li5Yongfeng Deng6Guoping Zhang7Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USADepartment of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA; Corresponding authors.Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA; State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, ChinaDepartment of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA; College of Transportation Engineering, Dalian Maritime University, Dalian, Liaoning 116026, China; Corresponding authors.Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA; School of Civil Engineering, Beijing Jiaotong University, Beijing, 100044, ChinaDepartment of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA; Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai, 200092, ChinaInstitute of Geotechnical Engineering, School of Transportation, Southeast University, Nanjing 211189, ChinaDepartment of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA; Corresponding authors.Three-dimensional superhydrophobic materials are characterized by a low surface energy and extremely low strength, and hence require reinforcement for viable applications. An experimental study is presented of the processing and mechanical properties of a graphene-reinforced superhydrophobic siloxane, synthesized by a sol–gel approach integrating alkali activation of metakaolin, hydrolysis of alkoxysilane, dispersion of graphene into the precursor, and co-condensation. To promote uniform dispersion and distribution of graphene, three processing techniques were used: while ultrasonication was adopted to disperse graphene nanoplatelets, accelerated condensation at 50 and 75 °C and varying the precursor’s viscosity used to prevent graphene from floating and re-aggregation. Results of nanoindentation, porosimetry, and unconfined compression show that adding 0.9 wt% graphene increases the strength of the superhydrophobic composites from ∼ 0 to 34 MPa. Slow condensation and curing at 25 °C allow graphene to re-aggregate and float upward in the sol, leading to its heterogeneous distribution. Despite its function in improving microscale dispersion, ultrasonication detrimentally decreases the composite’s strength due to acoustic cavitation. Similarly, curing at elevated temperatures accelerates co-condensation and results in a more uniform distribution of graphene, but induces thermal cavitation and bubble formation, because the threshold for acoustic and thermal cavitations is significantly reduced by superhydrophobicity.http://www.sciencedirect.com/science/article/pii/S026412752300271XAlkali activationCavitationGrapheneSiloxaneSol-gelSuperhydrophobicity |
| spellingShingle | Li He Dongfang Wang Tiantian Ma Jinliang Song Yongkang Wu Yucheng Li Yongfeng Deng Guoping Zhang Processing and properties of a graphene-reinforced superhydrophobic siloxane Materials & Design Alkali activation Cavitation Graphene Siloxane Sol-gel Superhydrophobicity |
| title | Processing and properties of a graphene-reinforced superhydrophobic siloxane |
| title_full | Processing and properties of a graphene-reinforced superhydrophobic siloxane |
| title_fullStr | Processing and properties of a graphene-reinforced superhydrophobic siloxane |
| title_full_unstemmed | Processing and properties of a graphene-reinforced superhydrophobic siloxane |
| title_short | Processing and properties of a graphene-reinforced superhydrophobic siloxane |
| title_sort | processing and properties of a graphene reinforced superhydrophobic siloxane |
| topic | Alkali activation Cavitation Graphene Siloxane Sol-gel Superhydrophobicity |
| url | http://www.sciencedirect.com/science/article/pii/S026412752300271X |
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