Effects of dispersion methods on dynamic and thermal mechanical properties of GNP–epoxy nanocomposite coatings

IF 7.3 2区材料科学 Q1 CHEMISTRY, APPLIED

Progress in Organic Coatings Pub Date : 2025-09-09 DOI:10.1016/j.porgcoat.2025.109652

Sudeep Louis , Ravi Arukula , Dannie Yang , Taehyun Kim , Xiangfa Wu , Xiaoning Qi

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引用次数: 0

Abstract

Graphene nanoplatelets (GNPs), as a filler, can greatly alter the mechanical and physical properties of a composite coating even at a minimal loading. Recent cost reduction of GNPs makes it an attractive coating filler option. However, due to their tendency to cluster, dispersing GNPs in a coating resin for practical applications remains a challenge. Herein, we report the effects of three practically used industrial dispersion methods on GNP dispersion profiles and the consequent properties of GNP-epoxy nanocomposite coatings. We studied two GNP loading levels: 0.3 wt% and 0.5 wt%, each dispersed with three different methods: high-speed disk dispersing (HSD), low-speed medium milling (LSM), and ultrasonication (USN). Optical microscopy and single particle optical sensing (SPOS) were used to obtain dispersion profiles by measuring parameters such as GNP particle/cluster size, size distribution (D10, D50, D90), and particle/cluster shape (circularity). At lower loading (0.3 wt%), coatings with GNPs dispersed by LSM showed enhanced toughness (4332.3 J/m³), elongation at break (205.1 %), and tensile strength (24.0 MPa) attributed to the breakdown of large clusters (D90 = 6.1 μm), which likely improves stress transfer within the coating matrix. The HSD method produced smaller (D90 = 7.1 μm) and irregular clusters (circularity ˂1), resulting in a coating with a higher tensile strength (29.9 MPa), but reduced toughness and brittle behavior. The USN method resulted in relatively broader CED with minimal cluster breakdown (D90 = 13.2 μm), but the coating shows balanced mechanical properties. Increasing the GNP loading to 0.5 wt% broadened the particle size distribution (PSD) from the LSM and HSD methods, leading to reduced stiffness and toughness. In contrast, at higher loading, the USN method produced smaller particles (85.2 % of particles being within the 1.5–2.5 μm range) with improved shape regularity (circularity ∼1), resulting in elevated glass transition temperature (Tg), modulus, and tensile strength. However, this narrow distribution also caused a notable reduction in toughness (195.2 J/m³) and elongation at break (9.42 %). These findings show strong effects of PSD, circularity, and GNP loading on coating properties, demonstrating that dispersion methods are a key factor in nanocomposite coating design.

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分散方式对gnp -环氧纳米复合涂层动态和热力学性能的影响

石墨烯纳米片（GNPs）作为一种填料，即使在最小的载荷下也能极大地改变复合涂层的机械和物理性能。最近GNPs的成本降低使其成为一种有吸引力的涂层填料选择。然而，由于GNPs倾向于聚集，将其分散在涂层树脂中用于实际应用仍然是一个挑战。在此，我们报告了三种实际使用的工业分散方法对GNP分散曲线和GNP-环氧纳米复合涂层性能的影响。我们研究了两种GNP负载水平：0.3 wt%和0.5 wt%，每一种都用三种不同的方法进行分散：高速磁盘分散（HSD）、低速介质研磨（LSM）和超声（USN）。光学显微镜和单颗粒光学传感（SPOS）通过测量GNP颗粒/簇大小、尺寸分布（D10、D50、D90）和颗粒/簇形状（圆度）等参数来获得弥散曲线。在较低的载荷（0.3 wt%）下，经LSM分散的GNPs涂层显示出更高的韧性（4332.3 J/m3）、断裂伸长率（205.1%）和抗拉强度（24.0 MPa），这是由于大簇（D90 = 6.1 μm）的破裂，这可能改善了涂层基体内的应力传递。HSD法得到了更小的（D90 = 7.1 μm）和不规则的团簇（圆度小于1），导致涂层具有更高的抗拉强度（29.9 MPa），但韧性和脆性降低。USN方法的阴极衍射区相对较宽，簇击穿最小（D90 = 13.2 μm），但涂层表现出平衡的力学性能。将GNP载荷增加到0.5 wt%，增大了LSM和HSD方法的粒径分布（PSD），导致刚度和韧性降低。相比之下，在更高的载荷下，USN方法产生更小的颗粒（85.2%的颗粒在1.5-2.5 μm范围内），具有更好的形状规律性（圆度~ 1），从而提高了玻璃化转变温度（Tg）、模量和抗拉强度。然而，这种窄分布也导致了韧性（195.2 J/m3）和断裂伸长率（9.42%）的显著降低。这些发现表明PSD、圆度和GNP载荷对涂层性能有很强的影响，表明分散方法是纳米复合涂层设计的关键因素。

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来源期刊

Progress in Organic Coatings 工程技术-材料科学：膜

CiteScore

11.40

自引率

15.20%

发文量

577

审稿时长

48 days

期刊介绍： The aim of this international journal is to analyse and publicise the progress and current state of knowledge in the field of organic coatings and related materials. The Editors and the Editorial Board members will solicit both review and research papers from academic and industrial scientists who are actively engaged in research and development or, in the case of review papers, have extensive experience in the subject to be reviewed. Unsolicited manuscripts will be accepted if they meet the journal''s requirements. The journal publishes papers dealing with such subjects as: • Chemical, physical and technological properties of organic coatings and related materials • Problems and methods of preparation, manufacture and application of these materials • Performance, testing and analysis.