Hindered cracking in colloidal suspension coatings via evaporation-driven lyotropic liquid crystals

IF 3.5 3区工程技术 Q2 ENGINEERING, CHEMICAL

AIChE Journal Pub Date : 2025-03-29 DOI:10.1002/aic.18837

Masato Yamamura

引用次数: 0

Abstract

We demonstrate that lyotropic liquid crystalline (LC) phases, formed by the molecular interactions between 1-glyceryl monooleyl ether (GME) and water, offer new pathways for producing crack-free particulate films from colloidal suspensions. Drying experiments on titanium dioxide-ethanol-water-GME suspension systems revealed a 15-fold increase in the critical cracking thickness, above which cracks spontaneously evolve, compared to suspensions without additives. Contrary to previous theoretical predictions based on capillary forces, the critical thicknesses ethanol-lean suspensions increased with higher particle packing volume fractions in the dried films. We developed a new phenomenological model that incorporates the formation of viscoelastic LC phases and found it to be in quantitative agreement with measurements. This suggests a versatile route for delaying cracking by introducing thermodynamically metastable phases of amphiphilic molecules. The evaporation-induced isotropic-LC transition was further verified by numerical predictions of the compositional trajectories on the phase diagram.

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通过蒸发驱动的溶致液晶抑制胶态悬浮涂层的开裂

我们证明了由1-甘油单油基醚（GME）和水之间的分子相互作用形成的溶致液晶（LC）相，为从胶体悬浮液中产生无裂纹颗粒膜提供了新的途径。对二氧化钛-乙醇-水- gme悬浮液系统的干燥实验表明，与不添加添加剂的悬浮液相比，临界裂纹厚度增加了15倍，超过该厚度，裂纹会自发发展。与先前基于毛细力的理论预测相反，随着干燥膜中颗粒堆积体积分数的增加，乙醇-稀薄悬浮液的临界厚度也随之增加。我们开发了一个新的现象学模型，其中包含粘弹性LC相的形成，并发现它与测量结果在定量上一致。这提出了一种通过引入两亲分子的热力学亚稳相来延缓裂解的通用途径。通过对相图上组分轨迹的数值预测，进一步验证了蒸发诱导的各向同性- lc转变。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

AIChE Journal 工程技术-工程：化工

CiteScore

7.10

自引率

10.80%

发文量

411

审稿时长

3.6 months

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