Composite coatings or films with polytetrafluoroethylene (PTFE) are typically utilized to offer superhydrophobic surfaces. However, the superhydrophobic surfaces usually have limited durability and require complicated fabrication methods. Herein, we report the successful integration of PTFE with ZnO ceramics to achieve superhydrophobicity via a one-step sintering method, cold sintering process (CSP), at 300 ℃. (1–x) ZnO–x PTFE ceramic composites with x ranging from 0 to 70 vol% are densified with relative density of over 97%. Micro/nano-scale PTFE polymer is dispersed among ZnO grains forming polymer grain boundary phases, which modulate surface morphology and surface energy of the ZnO–PTFE ceramic composites. For the 60 vol% ZnO–40 vol% PTFE ceramic composite, superhydrophobic properties are optimized with static water contact angles (WCAs) and sliding angles (SAs) of 162° and 7°, respectively. After abrading into various thicknesses (2.52, 2.26, and 1.99 mm) and contaminating with graphite powders on the surface, WCA and SA are still maintained with a high level of 157°–160° and 7°–9.3°, respectively. This work indicates that CSP provides a promising pathway to integrate polymers with ceramics to realize stable superhydrophobicity.

A series of high-k [(Na_0.5Bi_0.5)_xBi_1−x](W_xV_1−x)O₄ (abbreviated as NBWV(x value)) solid solution ceramics with a scheelite-like structure are synthesized by a modified solid-state reaction method at the temperature range of 680–760 ℃. A monoclinic (0 ≤ x < 0.09) to tetragonal scheelite (0.09 ≤ x ≤ 1.0) structural phase transition is confirmed by X-ray diffraction (XRD), Raman, and infrared (IR) analyses. The effect of structural deformation and order–disorder caused by Na⁺/Bi³⁺/W⁶⁺ complex substitution on microwave dielectric properties is investigated in detail. The compositional series possess a wide range of variable relative permittivity (ε_r = 24.8–80) and temperature coefficient of resonant frequency (TCF value, −271.9–188.9 ppm/℃). The maximum permittivity of 80 and a high Q×f value of ~10,000 GHz are obtained near the phase boundary at x = 0.09. Furthermore, the temperature-stable dielectric ceramics sintered at 680 ℃ with excellent microwave dielectric properties of ε_r = 80.7, Q×f = 9400 GHz (at 4.1 GHz), and TCF value = −3.8 ppm/℃ are designed by mixing the components of x = 0.07 and 0.08. In summary, similar sinterability and structural compatibility of scheelite-like solid solution systems make it potential for low-temperature co-fired ceramic (LTCC) applications.