The rheologically-complex fluid beauty of nail lacquer formulations
The rheologically-complex fluid beauty of nail lacquer formulations
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指甲油配方的流变复杂流体美感
DOI：
10.1039/d0sm02248a
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发表时间：
2021
期刊：
影响因子：
3.4
通讯作者：
Sharma, Vivek
中科院分区：
文献类型：
--
作者：
Jimenez, Leidy Nallely;Martínez Narváez, Carina D.;Xu, Chenxian;Bacchi, Samantha;Sharma, Vivek
指甲漆配方是含有添加剂的多组分复杂流体，这些添加剂会影响颜色、气味、质地、挥发率、粘度、稳定性、流平性、消费者的感官体验以及干涂层的装饰和耐磨性能。优化和表征配方的流变性对于延长保质期、更好地控制指甲涂装过程和附着力、连续生产大批量产品以及提高总体消费者满意度至关重要。指甲油的分配、瓶装、刷子涂抹和滴水以及感知到的粘性，都涉及到与强烈的伸展变形场相关的毛细驱动的挤压流动。然而，对多组分配方，特别是粘弹性溶液中的颗粒悬浮液的收缩动力学和拉伸流变学响应的表征明显不足，这促使了本研究。在这里，我们使用扭转流变仪来表征12种商用指甲漆配方的剪切流变学响应，并使用我们开发的滴入基材(DOS)流变仪来表征收缩动力学和拉伸流变学响应。我们可视化并分析刷子负载、指甲涂层、刷子滴水、下垂和指甲上漆的应用，以概述自由表面流动和非牛顿流变学带来的挑战。我们发现，用DOS流变仪得到的半径随时间的演化呈现出与剪切变薄不同的幂指数。剪切粘度和拉伸粘度均随变形速率的增加而减小。然而，拉伸粘度在最高速率下似乎与速率无关，并且显示出比高剪切速率粘度大近一个数量级的值。我们预计，通过更好地描述和了解颗粒和聚合物等成分对流变学、加工和应用的影响，这里描述的发现和方案将帮助和激励工业科学家设计更好的多组分配方。
Nail lacquer formulations are multi-ingredient complex fluids with additives that affect color, smell, texture, evaporation rate, viscosity, stability, leveling behavior, consumer's sensory experience, and dried coating's decorative and wear performance. Optimizing and characterizing the formulation rheology is critical for achieving longer shelf-life, better control over the nail painting process and adhesion, continuous manufacturing of large product volumes, and increasing overall consumer satisfaction. Dispensing, bottle filling, brush application, and dripping, as well as perceived tackiness of nail polishes, all involve capillarity-driven pinching flows associated with strong extensional deformation fields. However, a significant lack of characterization of pinching dynamics and extensional rheology response of multicomponent formulations, especially particle suspensions in viscoelastic solutions, motivates this study. Here, we characterize the shear rheology response of twelve commercial nail lacquer formulations using torsional rheometry and characterize pinching dynamics and extensional rheology response using dripping-onto-substrate (DoS) rheometry protocols we developed. We visualize and analyze brush loading, nail coating, dripping from brush, sagging, and lacquer application on a nail to outline the challenges posed by free-surface flows and non-Newtonian rheology. We find that the radius evolution over time obtained using DoS rheometry displays power law exponents distinct from those exhibited in shear thinning. Both shear and extensional viscosity decrease with deformation rate. However, the extensional viscosity appears to be rate-independent at the highest rates and displays nearly an order of magnitude larger values than the high shear rate viscosity. We envision that the findings and protocols described here will help and motivate industrial scientists to design better multicomponent formulations through a better characterization and understanding of the influence of ingredients like particles and polymers on rheology, processing, and applications.