The thermal insulators with extraordinarily ultra-low dielectric constants (k < 2.0) show great application potentials of superior insulators in microelectronics and semiconductor industry. We report here a class of ordered mesoporous silicas (OMSs) with ultra-low dielectric constants synthesized from a high-temperature hydrothermal strategy (~ 200 °C), in which amphiphilic triblock copolymer (P123: PEO₂₀-PPO₇₀-PEO₂₀, F127: PEO₁₀₆-PPO₇₀-PEO₁₀₆) was used as a soft template and inorganic salts (e.g. K₂SO₄) was employed as framework condensation promoter. Characterizations of small angle XRD patterns and N₂ isotherms show that the resultant OMSs possess ordered mesostructure, large BET surface area (197–829 m²/g), tunable micro-mesopore volumes (V_micro: 0–0.08 cm³/g, V_meso: 0.22–1.19 cm³/g). ²⁹Si MAS NMR spectra show that these OMSs samples have much enhanced crosslinking degree of silicon framework in comparison with the samples synthesized at low temperatures. Interestingly, the OMSs exhibit extraordinarily ultra-low k values up to 1.28, which is interpreted by a collaborative effect of tunable large pore volume and highly crosslinked silicon framework with rather limited surface hydroxyl group.

具有超低介电常数 ( k  < 2.0)的热绝缘体显示出优良绝缘体在微电子和半导体行业的巨大应用潜力。我们在此报告了一类具有超低介电常数的有序介孔二氧化硅 (OMS)，其由高温水热策略 (~200 °C) 合成，其中两亲性三嵌段共聚物 (P123: PEO ₂₀ -PPO ₇₀ -PEO ₂₀ , F127：PEO ₁₀₆ -PPO ₇₀ -PEO ₁₀₆）用作软模板和无机盐（例如K ₂ SO ₄)用作骨架缩合促进剂。小角度XRD图谱和N ₂等温线的表征表明，所得OMS具有有序的细观结构、大的BET表面积（197-829 m ² /g）、可调节的微介孔体积（V _micro：0-0.08 cm ³ /g， V中_观：0.22-1.19 cm ³ /g)。²⁹ Si MAS NMR谱表明，与低温合成的样品相比，这些OMSs样品的硅骨架交联度大大提高。有趣的是，OMS 表现出非常低的k 值高达 1.28，这是通过可调节的大孔体积和具有相当有限的表面羟基的高度交联的硅骨架的协同效应来解释的。