An alternative design of the measurement capacitor for high-pressure studies of complex liquids or soft matter systems is presented. Subsequently, results for the precritical anomaly of dielectric constant in 1-nitropropane–octane critical mixture are reported. First, the pressure dependence of the critical consolute temperature $T_C$ up to $P=0.55\mathrm{GPa}$ was determined and portrayed using the derivative-based analysis. Second, temperature and pressure evolutions of dielectric constant on approaching the critical consolute point at ($T_C=304.1\mathrm{K}$ and $P_C=403\mathrm{MPa}$) were studied. They revealed that the pretransitional anomaly $\varepsilon \left(P\to P_C\right)$ is notably more pronounced than for $\varepsilon \left(T\to T_C\right)$. For both paths, the static domain extends even to as low frequency as $f=100\mathrm{Hz}$, whereas for tests under atmospheric pressure, they require at least $f=100\mathrm{kHz}$. The discussion of the impact of correction-to-scaling terms, including the unique case of the pressure paths, is also presented.

中文翻译：

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二元临界混合物中介电常数的高压行为

提出了用于复杂液体或软物质系统高压研究的测量电容器的替代设计。随后，报道了1-硝基丙烷-辛烷临界混合物中介电常数的临界前异常结果。首先，临界固溶温度的压力依赖性${Ť}_C$ 取决于 $P=0.55\mathrm{GPa}$确定和描绘使用基于导数的分析。其次，介电常数的温度和压力在（${Ť}_C=304.1\mathrm{ķ}$ 和 $P_C=403\mathrm{兆帕}$）进行了研究。他们发现过渡前异常$\varepsilon （P\to P_C）$ 明显比 $\varepsilon （Ť\to {Ť}_C）$。对于这两个路径，静态域甚至扩展到与$F=100\mathrm{赫兹}$，而在大气压下进行测试至少需要 $F=100\mathrm{千赫}$。还介绍了按比例缩放项的影响的讨论，包括压力路径的特殊情况。