文章信息/Info

Title:

硅烯在水化硅酸鈣表面成核與生長的理論研究

文章編號:

1674-3962(2020)06-0430-07

作者:

ZHOU Yang1; 2;  ZHENG Haojie1;  QIU Yuwen1;  ZOU Xixi1;  HUANG Jiale1

(1. School of Materials Science and Engineering, Southeast University, Nanjing 211189, China) （2. State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co��, Ltd��, Nanjing 211103, China)

Author(s):

周揚1; 2; 鄭浩杰1; 邱鈺雯1; 鄒茜茜1; 黃家樂1

（1.東南大學材料科學與工程學院，江蘇 南京 211189）（2.江蘇省建筑科學研究院有限公司 高性能土木工程材料國家重點實驗室，江蘇 南京 211103）

關鍵詞:

silicene;  calcium silicate hydrates;  molecular dynamics;  nucleation;  growth

Keywords:

硅烯; 水化硅酸鈣; 分子動力學; 成核; 生長

分類號:

TU526

DOI:

10.7502/j.issn.1674-3962.202004006

文獻標志碼:

A

摘要:

Silicene, a newly emerging two�瞕imensional (2D) material, can be a superior reinforcement candidate to enhance the mechanical performance of calcium silicate hydrates (C-S-H, the primary hydration product of portland cement), in consideration of the common substrate atom Si. Here, with the reactive molecular dynamics simulations, the possibility of depositing such a silicene monolayer on the C-S-H surface was investigated. The results indicate that high-reactivity non-bridging oxygen atoms (NBOs) on the C-S-H surface facilitates the nucleation of silicon atoms, by the formation of high-strength Si-O-Si bonds. The nucleated silicon clusters follow a relatively uniform distribution over the whole surface. As the deposition continues, clusters grow larger, leading to the merging and coalescences of neighboring ones, via the formation of bridging bonds and the transformation of cluster shape. Eventually, a relatively complete silicene monolayer has been successfully established on the C-S-H surface, with high surface coverage ratio. Furthermore, it suggests the deposition rate and temperature may substantially affect the nucleation and growth process of silicene. This study opens the perspective of depositing a 2D material on an inorganic matrix and elucidates the atomic stacking mechanism on the interfaces.

Abstract:

硅烯作為一種新興二維材料，與水化硅酸鈣（C-S-H，硅酸鹽水泥最主要的水化產物）同為硅質基底材料，將其與水化硅酸鈣復合或能有效提高水化硅酸鈣的韌性。基于分子動力學模擬技術，探索了單層硅烯在水化硅酸鈣表面成核生長的可能性。模擬結果顯示，通過與沉積硅原子形成高強度的Si-O-Si鍵，水化硅酸鈣表面的高反應活性非橋接氧原子（NBOs）促進了硅原子團簇的成核，已成核的硅原子團簇在水化硅酸鈣表面均勻分布。隨著硅原子的進一步沉積，已成核的硅原子團簇進一步生長，通過橋接鍵的形成和團簇形狀的改變，相鄰的小團簇發生合并，形成大團簇。最終，一片較為完整的單層硅烯在水化硅酸鈣表面生長出來，且表面覆蓋率高。在上述過程中，硅原子的沉積速率以及沉積溫度對硅烯的成核和生長過程具有一定的影響。該研究為無機材料表面沉積二維材料開辟了前景，并揭示了其界面處的原子堆積機制。