Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
J Mech Behav Biomed Mater. 2022 Jan;125:104947. doi: 10.1016/j.jmbbm.2021.104947. Epub 2021 Oct 29.
A mesoporous silica aerogel (SiA) with a high specific surface area was synthesized through the sol-gel process and subsequently modified with two different silane-based modifiers to reveals the effect of microstructure and surface modification on the fracture mechanics of a dental composite. The synthesized and modified aerogel were characterized using field-emission scanning electron microscopy (FESEM), nitrogen adsorption-desorption, and Fourier-transform infrared spectroscopy (FTIR). The prepared aerogels were then incorporated within methacrylate-based dental composites with the filler content of 0-35 wt%. Flexural modulus (FM) and Flexural strength (FS) were evaluated by the three-point bending test. The fracture toughness (FT) of the composites was evaluated by single edge V-notched beam (SEVNB) flexure test, while FESEM was employed to investigate the fracture surface morphology of the composites. Furthermore, the wettability of the composites was assessed according to the sessile drop method. The characterization of synthesized aerogels revealed the formation of SiA with a surface area of 550-560 m/g and porosity of 77%, while FTIR results confirmed the successful modification. Statistical analysis (ANOVA, p≤0.05, and n = 5) revealed that FM significantly enhanced (from 1.43 GPa to 2.66 GPa) as filler content increased over 0-30 wt%, and FS improved (from 80 to 95 MPa) as filler content increased over 0-15 wt%. Furthermore, the modification of aerogels improved both fracture characteristics and the wettability of the composites. The FT evaluations and fractography analysis revealed that the mesoporous structure of the fillers mainly dominated the filler-matrix adhesion strength at the same filler content.
一种具有高比表面积的介孔硅气凝胶（SiA）是通过溶胶-凝胶法合成的，然后用两种不同的硅烷基改性剂进行改性，以揭示微观结构和表面改性对牙科复合材料断裂力学的影响。使用场发射扫描电子显微镜（FESEM）、氮气吸附-解吸和傅里叶变换红外光谱（FTIR）对合成和改性的气凝胶进行了表征。然后将制备的气凝胶以 0-35wt%的填充量掺入甲基丙烯酸酯基牙科复合材料中。通过三点弯曲试验评估弯曲模量（FM）和弯曲强度（FS）。通过单边 V 型缺口梁（SEVNB）弯曲试验评估复合材料的断裂韧性（FT），同时采用 FESEM 研究复合材料的断裂表面形貌。此外，根据 sessile drop 方法评估复合材料的润湿性。合成气凝胶的表征表明形成了比表面积为 550-560m/g、孔隙率为 77%的 SiA，而 FTIR 结果证实了成功的改性。统计分析（ANOVA，p≤0.05，n=5）表明，随着填充量从 0 增加到 30wt%，FM 显著增加（从 1.43GPa 增加到 2.66GPa），而 FS 随着填充量从 0 增加到 15wt%而增加（从 80MPa 增加到 95MPa）。此外，气凝胶的改性提高了复合材料的断裂特性和润湿性。FT 评估和断口分析表明，在相同填充量下，填料的介孔结构主要控制着填料-基质的附着力。
