Crystallizable Surfactant-Based Interfacial Layers for Stabilizing Nonaqueous Photocurable Foams

In this work, we introduce a crystallization-assisted strategy to stabilize nonaqueous foams in low-surface-tension photocurable resin systems. A stearyl alcohol/stearic acid (SAL/SAC, 7:3) crystalline surfactant blend functions as a Pickering-type stabilizer, forming a interfacial solid layer around entrapped air bubbles that suppresses coalescence and preserves foam morphology. Resin formulations containing 10 wt % SAL/SAC exhibited excellent stability, maintaining intact foam structures for more than 7 days. Incorporation of 4 wt % Triton X-100 further reduced SAL/SAC crystal size to ∼2.5 μm, enabled air incorporation up to 40 vol %, and lowered the cured foam density from 0.992 to 0.632 g cm–3. Despite this substantial lightweighting, the DLP-printed foams retained high mechanical performance, achieving a compressive strength of 26.85 MPa and a break strain of 65%. The crystallization-driven interfacial stabilization mechanism offers precise control over bubble morphology, dispersion uniformity, and photopolymerization behavior, ensuring reliable processing in Digital Light Processing (DLP) systems. This materials platform provides a scalable route for producing structurally robust nonaqueous photocurable foams, unlocking opportunities for lightweight lattices, energy-absorbing components, and advanced thermal-insulation materials.