Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Abstract

The development of polymer materials with high intrinsic thermal conductivity is essential for efficient heat dissipation in next-generation electronics. In this study, we report the fabrication and characterization of liquid-crystalline (LC) polyimide nanofibers (PI-NFs) designed to achieve a highly ordered internal structure. Highly aligned LC-PI-NFs were prepared via electrospinning of a poly(amic acid) precursor containing rigid phenyl benzoate mesogens and flexible dodecyl spacers, followed by stepwise thermal imidization. To further enhance molecular alignment, uniaxial tensile drawing was applied during the imidization process. Upon thermal imidization, wide-angle X-ray scattering (WAXS) revealed a phase transition from the initial smectic (Sm) A phase to a more ordered SmF phase. Furthermore, combined WAXS and small-angle X-ray scattering (SAXS) analyses suggested that uniaxial drawing enhances the ordering of the LC structure. Microscale temperature wave analysis demonstrated a positive correlation between the internal structural order and the thermal diffusivity along the fiber axis, which reached a value of 6.6 × 10–7 m2 s–1 (corresponding to a thermal conductivity of 1.0 W m–1 K–1) for the uniaxially drawn LC-PI-NFs. These results demonstrate that synergistically integrating LC phase behavior with processing-induced strain is a promising strategy for developing high-performance, thermally conductive polymer nanostructures.

DOI： 10.1021/acsapm.6c01583

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Other Link： https://pubs.acs.org/aapmcd/article-pdf/8/16/13702/66415494/acsapm.6c01583.pdf

Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Emerging high-frequency electronics require polymer dielectrics that combine a low dielectric constant ( D _k ) with an ultra-low dissipation factor ( D _f ) under realistic humidity. Here, we report semi-aromatic polyimides (PIs) incorporating cyclohexyl-substituted double-decker-shaped silsesquioxane (C-DDSQ) units that simultaneously suppress electronic and dipolar polarizations while limiting water uptake. The best formulation shows D _k  = 2.57 and D _f  = 0.0019 at 10 GHz under 30% RH, and maintains minimal changes up to 60% RH ( ΔD _k  ≈ 0.02, ΔD _f  ≈ 0.0003). Wide-angle X-ray diffraction confirms the retention of the cage-like silsesquioxane motif, and thermogravimetric analysis shows T _d-10  ≥ 470 °C, indicating robust thermal endurance. Correlating D _k with in-plane refractive index ( n _TE ) reveals that the lowered n and the rigid, hydrophobic architecture of C-DDSQ account for the low losses at 10–20 GHz. These results position C-DDSQ-incorporating semi-aromatic PIs as promising interlayer dielectrics that deliver ultra-low loss, humidity stability, and high thermal tolerance without resorting to porosity or heavy fluorination.

DOI： 10.1038/s43246-026-01217-7

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Other Link： https://www.nature.com/articles/s43246-026-01217-7

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.macromol.6c00175

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Authorship：Lead author   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acs.macromol.5c00730

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

<jats:title>Abstract</jats:title><jats:p>Owing to their low dielectric constant (<jats:italic>D</jats:italic><jats:sub>k</jats:sub>), processability, and mechanical properties, siloxane‐based polymers have attracted attention as insulating materials for next‐generation communication. However, a major challenge regarding siloxane‐containing materials is their high dielectric loss tangent (dissipation factor) (<jats:italic>D</jats:italic><jats:sub>f</jats:sub>). A polymer is designed and synthesized by combining polysiloxanes with phenyl side groups on the main chain and a polyimide structure (polysiloxane‐imide) to improve the <jats:italic>D</jats:italic><jats:sub>f</jats:sub> value. Compared with conventional dimethylsiloxane‐based polymers, the resulting polysiloxane‐imide, obtained as a bendable, self‐supporting film, exhibits a significantly reduced <jats:italic>D</jats:italic><jats:sub>f</jats:sub> value. The rigidity of the phenyl group‐containing polysiloxane presumably contributes to the improvement in the <jats:italic>D</jats:italic><jats:sub>f</jats:sub> value. Furthermore, polysiloxane‐imides exhibit excellent hydrophobicity and high heat resistance with their 5% weight loss temperature of over 400 °C. The synthesized polysiloxane‐imides with phenyl side groups, which possess various properties, including low <jats:italic>D</jats:italic><jats:sub>k</jats:sub>, low <jats:italic>D</jats:italic><jats:sub>f</jats:sub>, and excellent hydrophobicity, are expected to contribute to the future practical application of siloxane‐based insulating materials.</jats:p>

DOI： 10.1002/marc.202500115

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Event date： 2026.7

Presentation type：Oral presentation (invited, special)  

Country：China  

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Event date： 2026.6

Presentation type：Symposium, workshop panel (nominated)  

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