近日，河北工业大学苏敏团队研究了聚合物分子对咖啡因结晶针状形态及其流动性的调控。该研究于2025年10月28日发表在《颗粒学报》杂志上。

咖啡因（CAF）晶体容易形成高纵横比的针状形态，严重影响其后处理性能。为了实现晶体形态的精确控制，采用分子动力学模拟方法揭示针状晶体图案的形成机理。在此基础上，筛选了不同聚合物添加剂对CAF晶体的调控作用。

验证实验表明，具有较强疏水性和显著位阻的聚丙烯乙二醇1000 （PPG1000）可以通过降低（200）晶面与溶剂之间的界面相互作用能，显著降低CAF晶体的纵横比。在PPG1000添加量为0.82% （g/g溶剂）的情况下，成功制备了长径比约为16的棒状CAF晶体。此外，还测试了棒状晶体的攻丝密度和休止角。聚合物添加剂有效调节了CAF针状晶体的形态及其流动特性，对提高CAF晶体产品的性能和设计类似的针状晶体体系具有重要的科学和工程价值。

附：英文原文

Title: Regulation of polymer molecules on caffeine crystals of needle morphology and its flowability

Author: Min Su

Issue&Volume: 2025/10/28

Abstract: Caffeine (CAF) crystals tend to form a high aspect ratio needle-like morphology, which seriously affects their performance in the post-processing process. To achieve precise control of crystal morphology, molecular dynamics simulation was adopted to reveal the formation mechanism of needle-like crystal patterns. Based on this, the regulatory effects of various polymer additives on CAF crystals were screened. Verification experiment shows that polypropylene glycol 1000 (PPG1000) with strong hydrophobic properties and significant steric hindrance can significantly reduce the aspect ratio of CAF crystals by reducing the interfacial interaction energy between the (2 0 0) crystal plane and the solvent. Rod-shaped CAF crystals with a lower aspect ratio of approximately 16 were successfully prepared using PPG1000 addition amount of 0.82% (g/g solvent). Further, the tapped density and the Angle of repose of the rod crystals were also tested. The polymer additive has effectively regulated the morphology of the needle crystals of CAF and its flow characteristics, which has significant scientific and engineering value for improving the performance of CAF crystal products and the design of similar needle crystalline systems.

DOI: 10.1016/j.partic.2025.10.012

Source: https://www.sciencedirect.com/science/article/abs/pii/S1674200125002792