Abstract

SiO₂ is widely used in nanocomposites as reinforcement nanoparticle to enhance mechanical properties especially wear resistivity. Prior to use, surface modification with proper and sufficient coupling agent should be performed on it. Coupling agent concentration plays a key role in modification process.

Purpose

In this study, the influence of 3-(glycidoloxy propyl) trimethoxy silane (GPTMS) concentration on surface modification of SiO₂ nanoparticles, is experimentally investigated.

Methods

The surface modification of nano-silica were performed by 30, 50, 80 and 110 wt.% of GPTMS in order to introduce the optimal GPTMS concentration to complete the process. Fourier Transformation Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Thermo Gravimetric Analysis (TGA) and X-Ray Diffraction (XRD) characterized the pure and surface modified samples; then, the results were compared to each other to achieve the aim of the research.

Results

FTIR results confirmed the silanization proceed due to the silane absorption peak disappearing and shifting of the hydroxyl group bonds in to the amide bonds. This test showed that 30 wt.% GPTMS has not been sufficient for full functionalization of the NPs. According to FESEM images, it seems that the NPs were better modified by 80 wt.% GPTMS due to the least NPs aggregation and lack of coupling agent deposition on the NPs. Also, TGA illustrates that this sample has higher thermal stability because of lower weight loss (11.2%) in coupling agent decomposition temperature range: 130–380 °C. Furthermore, X-Ray Diffraction confirmed the FESEM and TGA results about the mentioned sample due to its highest crystallite size (increase 26.64% in crystallite size in comparison with the pure sample).

Conclusion

So, the 80 wt.% of GPTMS introduced as the optimal concentration for surface modification of SiO₂ nanoparticles.

中文翻译：

---

3-(缩水甘油氧基丙基)三甲氧基硅烷浓度对SiO2纳米颗粒表面改性的影响

摘要

SiO ₂广泛用于纳米复合材料中作为增强纳米粒子以提高机械性能，特别是耐磨性。使用前，应使用适当、足量的偶联剂对其进行表面改性。偶联剂浓度在改性过程中起关键作用。

目的

在这项研究中，实验研究了 3-(缩水甘油氧基丙基) 三甲氧基硅烷 (GPTMS) 浓度对 SiO ₂纳米粒子表面改性的影响。

方法

通过 30、50、80 和 110 wt.% 的 GPTMS 对纳米二氧化硅进行表面改性，以引入最佳 GPTMS 浓度以完成该过程。傅里叶变换红外光谱 (FTIR)、场发射扫描电子显微镜 (FESEM)、热重分析 (TGA) 和 X 射线衍射 (XRD) 对纯样品和表面改性样品进行了表征；然后，将结果相互比较，以达到研究的目的。

结果

FTIR结果证实了硅烷化由于硅烷吸收峰消失和羟基键转移到酰胺键而进行。该测试表明，30 wt.% GPTMS 不足以实现 NP 的完全功能化。根据 FESEM 图像，似乎 80 wt.% GPTMS 对 NPs 进行了更好的修饰，因为 NPs 聚集最少，并且在 NPs 上没有偶联剂沉积。此外，TGA 表明该样品具有更高的热稳定性，因为在偶联剂分解温度范围内（130–380 °C）具有更低的失重（11.2%）。此外，X 射线衍射证实了上述样品的 FESEM 和 TGA 结果，因为它具有最高的微晶尺寸（与纯样品相比，微晶尺寸增加了 26.64%）。

结论

因此，引入 80 wt.% 的 GPTMS 作为 SiO ₂纳米粒子表面改性的最佳浓度。