Junzhen Chen, Long Cheng, Dongsheng Hu, Yanpeng Si, Jianjun Jiang
To prepare polymer foams with low-density and high-energy absorption efficiency, this study designs epoxy foaming experiments employing the Box–Behnken method and investigates the impact of process parameters on the microscopic geometric parameters and uniaxial compression response of foam. Finite element analysis models are created to investigate the microscale deformation mechanism. The main results are as follows: 1) The average equivalent cell diameter is significantly affected by foaming temperature and foaming agent content, while cell wall thickness is more influenced by the foaming agent content and the precuring time. 2) The compression response is most significantly affected by foaming temperature, followed by foaming agent content, with precuring time showing less significant influence. The differences in the stress–strain curves during various stages of deformation are due to the buckling of cell walls and the subsequent collapse of cells. 3) Density exhibits a highly positive correlation with strength and modulus while showing a relatively high negative correlation with energy absorption efficiency. Based on these findings, process parameters are optimized using the Hooke–Jeeves algorithm and experimentally validated, demonstrating the reliability of the optimization strategy. The experimental design and process parameter optimization strategy can be applied to other polymer foaming research.
{"title":"Effect of Chemical Foaming Process Parameters on the Performance of Epoxy Foam and Parameter Optimization Strategies","authors":"Junzhen Chen, Long Cheng, Dongsheng Hu, Yanpeng Si, Jianjun Jiang","doi":"10.1002/adem.202402115","DOIUrl":"https://doi.org/10.1002/adem.202402115","url":null,"abstract":"<p>To prepare polymer foams with low-density and high-energy absorption efficiency, this study designs epoxy foaming experiments employing the Box–Behnken method and investigates the impact of process parameters on the microscopic geometric parameters and uniaxial compression response of foam. Finite element analysis models are created to investigate the microscale deformation mechanism. The main results are as follows: 1) The average equivalent cell diameter is significantly affected by foaming temperature and foaming agent content, while cell wall thickness is more influenced by the foaming agent content and the precuring time. 2) The compression response is most significantly affected by foaming temperature, followed by foaming agent content, with precuring time showing less significant influence. The differences in the stress–strain curves during various stages of deformation are due to the buckling of cell walls and the subsequent collapse of cells. 3) Density exhibits a highly positive correlation with strength and modulus while showing a relatively high negative correlation with energy absorption efficiency. Based on these findings, process parameters are optimized using the Hooke–Jeeves algorithm and experimentally validated, demonstrating the reliability of the optimization strategy. The experimental design and process parameter optimization strategy can be applied to other polymer foaming research.</p>","PeriodicalId":7275,"journal":{"name":"Advanced Engineering Materials","volume":"27 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karthick Sekar, Johann Bouclé, Raphaël Doineau, Souhir Azzaz, Bruno Schmaltz, Guylaine Poulin-Vittrant
Understanding the impact of the aluminum zinc oxide (AZO) seed layer thickness on zinc oxide nanowires (ZnO NWs) growth is decisive in attaining high-quality NWs with higher transparency and without cracking issues when using flexible substrates, especially for optoelectronic applications. Therefore, herein, ZnO NWs have been grown on various thicknesses of AZO films deposited onto flexible substrates (PET, PET/ITO (60 Ω sq−1) and (200 Ω sq−1)) through a simple, low-temperature hydrothermal growth process. Based on AZO layer thickness, structural, optical, morphological, and topographical properties have been systematically investigated. The results demonstrate that 1) thicker AZO films (≈250 nm) increase the crystallinity of the ZnO NWs than thinner AZO films (≈200 and 100 nm). 2) ZnO NWs on the thicker AZO films with different ITO grades (60 or 200 Ω sq−1) provide an optical bandgap value of 3.24–3.27 eV and offer good transmittance (>80%) in the visible range. 3) The AZO film thickness strongly influences ZnO NWs growth, especially NWs’ average diameter and density. 4) Annealing the samples at 100 °C after NW growth is pointless. Overall, the findings demonstrate efficient tuning of the ZnO NW properties that exhibit promising potentiality for perovskite solar cells, which have also been preliminarily tested.
{"title":"Impact of Sputtered AZO Seed Layer Thickness on Hydrothermally Grown ZnO Nanowires Properties for Flexible Perovskite Solar Cells","authors":"Karthick Sekar, Johann Bouclé, Raphaël Doineau, Souhir Azzaz, Bruno Schmaltz, Guylaine Poulin-Vittrant","doi":"10.1002/adem.202401356","DOIUrl":"https://doi.org/10.1002/adem.202401356","url":null,"abstract":"<p>Understanding the impact of the aluminum zinc oxide (AZO) seed layer thickness on zinc oxide nanowires (ZnO NWs) growth is decisive in attaining high-quality NWs with higher transparency and without cracking issues when using flexible substrates, especially for optoelectronic applications. Therefore, herein, ZnO NWs have been grown on various thicknesses of AZO films deposited onto flexible substrates (PET, PET/ITO (60 Ω sq<sup>−1</sup>) and (200 Ω sq<sup>−1</sup>)) through a simple, low-temperature hydrothermal growth process. Based on AZO layer thickness, structural, optical, morphological, and topographical properties have been systematically investigated. The results demonstrate that 1) thicker AZO films (≈250 nm) increase the crystallinity of the ZnO NWs than thinner AZO films (≈200 and 100 nm). 2) ZnO NWs on the thicker AZO films with different ITO grades (60 or 200 Ω sq<sup>−1</sup>) provide an optical bandgap value of 3.24–3.27 eV and offer good transmittance (>80%) in the visible range. 3) The AZO film thickness strongly influences ZnO NWs growth, especially NWs’ average diameter and density. 4) Annealing the samples at 100 °C after NW growth is pointless. Overall, the findings demonstrate efficient tuning of the ZnO NW properties that exhibit promising potentiality for perovskite solar cells, which have also been preliminarily tested.</p>","PeriodicalId":7275,"journal":{"name":"Advanced Engineering Materials","volume":"27 4","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adem.202401356","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}