APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 11
·758
·
IF 2.7
Hao Lifeng,Lin Liyu,Jiang Zewen,Zhou Yang,Fang Yujie
Inspired by the fact that nanostructured expandable graphite (denoted as EG), when functionalized with silicon (Si) and boron (B) elements, can significantly enhance thermal insulation performance and improve the strength of char residue layers, the study controllably synthesizes EG supported with boron acid (H 3 BO 3 ) or polyhedral oligomeric silsesquioxane (POSS), using polydopamine (PDA) as a bridging agent. The resulting composites possess specific particle sizes of 80–90 nm and 100–120 nm for H 3 BO 3 -PDA-EG and POSS-PDA-EG, respectively. By formulating ablative-resistant coatings incorporating these composites, significant improvements are achieved in the mechanical properties of the resulting ceramic layers formed during ablation compared to control formulation. The compressive strength of the char residue layer is 0.13 MPa for EG alone, 8.85 MPa for H 3 BO 3 -PDA-EG, and 12.86 MPa for POSS-PDA-EG. Additionally, it is observed that the back surface of the coating with POSS-PDA-EG is approximately 180 ℃, while the back surface of the coating with H 3 BO 3 -PDA-EG is approximately 300 ℃ in a thermal test by a FD-04D/E Wind Tunnel, and compared to the coating with H 3 BO 3 -PDA-EG, the coating with POSS-PDA-EG yields more uniformly expanded and dense residue, which indicated that the coating with POSS-PDA-EG is characterized by better heat insulation and heat-resistant parameters. This is attributed to the improved silicon-boron coordination effect facilitated by the presence of POSS-PDA-EG and boron oxide, promoting ceramization. The resulting graphitized carbon layer, formed through fusion with porous expanded graphite at high temperatures, effectively resists high heat flow erosion over an extended duration. This work introduces an effective approach for enhancing ablation resistance by synergistically catalyzing boric acid or POSS-modified EG with a PDA bridge. The initial decomposition temperature was increased from 189 to 223 ℃, the maximum decomposition temperature was increased from 282 to 287℃, and the residual weight was increased from 51.6 to 63.6%. This can be concluded that the mixture of epoxy resin with either H 3 BO 3 -PDA-EG or POSS-PDA-EG demonstrates outstanding thermal resistance. The utilization of these novel composites and the insights gained from their performance contribute to advancements in the field of ablation-resistant coatings.
研究领域:
材料科学
·
聚合物涂层
·
热防护系统
·
烧蚀材料
·
纳米复合材料
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2019
·
IF 3.42
Haowei Huang,Menglan Li,Yuqin Tian,Yuhui Xie,Xinxin Sheng,Xiang Jiang,Xinya Zhang
Having high aspect ratio and excellent gas barrier property, two dimensional α-zirconium phosphate nanosheets (α-ZrP) are one of the promising anticorrosive nanofillers. In this work, under mild conditions, layered α-ZrP were effectively exfoliated by Tris buffer solution and functionalized by situ polymerization of polydopamine (PDA) in one pot. And then the functionalized α-ZrP (f-ZrP) were introduced into waterborne epoxy (WEP) coatings that were applied on the mild steel for electrochemical corrosion tests. Results of TEM, XRD and AFM reveal that α-ZrP are successfully exfoliated with an interlayer space of 1.72 nm and a thickness of 0.78 nm. Characterizations of FTIR spectra, TEM image and EDS mapping confirm that α-ZrP are decorated by PDA. With PDA decoration, f-ZrP gain a better compatibility with WEP than pristine α-ZrP do, leading to a homogeneous distribution in the polymer matrix. And the exfoliation by Tris buffer provides f-ZrP with high aspect ratio, which is beneficial for f-ZrP/WEP to fight against the permeation of corrosive mediums. Therefore, after 15-day immersion in 3.5 wt% NaCl solution, the f-ZrP/WEP composite coatings show high value of |Z 0.01Hz | (1.90 × 10 7 Ω·cm 2 ), which is about one order of magnitude over that of blank WEP coatings (2.33 × 10 6 Ω·cm 2 ).
研究领域:
材料科学
·
腐蚀工程
·
纳米复合材料
·
聚合物涂层
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·Vol. 11
·期 7
·6256-6265
·
IF 1.5
Jiheng Ding,Lin Gu,Wei Dong,Haibin Yu
The epoxidation modification of renewable lignin was achieved by using epichlorohydrin under alkaline condition. Modified lignin (ELG) was characterized by FTIR and used to improve the corrosion performance of epoxy coatings. SEM images showed that ELG was well-dispersed in epoxy coatings, indicating that good compatibility of modified lignin with the epoxy resin. The anticorrosive properties of ELG/epoxy coatings coated on Q235 steel in 3.5% NaCl solution were studied by polarization curves and electrochemical impedance spectroscopy (EIS). Compared with pure epoxy coating, the addition of ELG greatly improved the corrosion protection performance of Q235 steel. Especially, the epoxy coating with 2% ELG achieves high corrosion protection performance.
研究领域:
材料科学
·
腐蚀工程
·
聚合物涂层
·
绿色化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Zhihao Chen,Guohui Zhang,Wenzhong Yang,Bin Xu,Yun Chen,Xiaoshuang Yin,Ying Liu
The improvement in the long-term corrosion resistance of conducting polymer coatings was essential for protecting metal bipolar plate in proton exchange membrane fuel cell (PEMFC). In this study, carbon powders were functionalized with polydopamine (PDA) to create a more negative charge surface and their morphologies were examined by TEM test. Then, polypyrrole (PPy) coating was successfully electropolymerized on 304 stainless steel (304SS) in the presence of carbon powders (C and C-PDA powders). Therefore, the conducting property of PPy coating could be restored by incorporating carbon powders when the coating suffered aggressive attack. The structure, morphology and thermal-stability properties of the synthesized PPy, PPy/C and PPy/C-PDA coatings were investigated using SEM, AFM, FTIR and TG analysis. The anti-corrosion performances were also investigated in a simulated PEMFC working environment (0.1 M H 2 SO 4 solution). Electrochemical tests and immersion tests showed that PPy/C-PDA coating exhibited superior long-term corrosion resistance during 720 h of immersion and the pitting phenomenon of 304SS was evidently avoided. The PPy/C-PDA coating served as a superior physical barrier and provided excellent anodic protection effect and adhesion strength, with a low interfacial contact resistance.
研究领域:
材料科学
·
腐蚀工程
·
能源材料
·
电化学
·
聚合物涂层
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）