GOALI: Determination of the Structure and Properties of Microfibrillated Cellulose during Dynamic Phase Transitions

微原纤化纤维素（MFC）是造纸过程中产生的废物。 它在商业上被加工用于一些工业用途，但它也具有作为消费品，织物和家庭护理产品中的流变改性剂的潜在应用。 流变改性剂是添加到某些产品中以定制其流动行为的材料。 MFC是非离子的，这使得它与广泛的产品配方兼容，但它必须分散在整个产品中以改变产品的特性。 面临的挑战是，MFC是作为水中高度缠结的纤维的浓缩浆料提供的，这些纤维难以分散在大多数产品中。 这个GOALI项目是利哈伊大学和宝洁公司之间的合作，将研究MFC的结构如何取决于参数，如温度，主体溶液的组成和由于流动而施加在MFC上的力。 使用几种探测MFC纤维微观结构排列的技术，研究人员探索了可以增强MFC在有用产品中分散的微观结构的转变。 将来自造纸工业的MFC废物再利用为消费品的添加剂将减少对MFC处置的需要并降低有价值的消费品的制造成本。 研究团队将从事各种外展活动，包括在达芬奇科学中心开展项目，教育公众了解胶体和流变学，指导对STEM领域感兴趣的中学生和高中生，该GOALI项目的总体目标是表征MFC支架的时空流变学演变，使其能够作为一种流变改性剂，用于消费品、织物和家庭护理产品。MFC具有与当前使用的流变改性剂的纤维尺寸相当的纤维尺寸，但与其他改性剂不同，MFC在胶体上具有可忽略的电荷。MFC的潜在优势将探索通过表征MFC的微观结构演变，使用微观流变学和显微镜，通过表征MFC系统的体流变学的演变，并通过确定平衡性能和支架结构后，相变使用一个独特的微流体平台和多个粒子跟踪微观流变学。 MFC解决方案将在相变过程中，由于三个驱动力的特点：温度，周围的解决方案和流动引起的机械力的变化。这些知识将使这些材料能够用作配制产品行业的流变改性剂。研究结果将确定导致均匀MFC悬浮液的材料，并确定导致稳定悬浮液的微观结构和宏观结构和性能。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Microfibrillated cellulose (MFC) is a waste product generated during paper manufacturing. It is processed commercially for some industrial uses, but it also has a potential application as a rheological modifier in consumer, fabric and home care products. Rheological modifiers are materials added to certain products to customize their flow behavior. MFC is non-ionic, which makes it compatible with a wide range of product recipes, but it must be dispersed throughout a product to modify the product's properties. The challenge is that MFC is supplied as a concentrated slurry of highly entangled fibers in water that are difficult to disperse in most products. This GOALI project, which is a collaboration between Lehigh University and Procter and Gamble, will investigate how the structure of MFC depends on parameters such as the temperature, composition of the host solution and forces exerted on MFC due to flow. Using several techniques that probe the microstructural arrangements of the MFC fibers, the researchers explore transitions in the microstructure that can enhance dispersal of MFC in useful products. Repurposing MFC waste from the paper industry as additives for consumer products will reduce the need for MFC disposal and reduce manufacturing costs of valuable consumer products. The research team will engage in a variety of outreach activities, including programs at the Da Vinci Science Center to educate the public in colloids and rheology, mentoring middle school and high school students interested in STEM fields, and training undergraduate and graduate students in research.The overall goal of this GOALI project is to characterize the spatial and temporal rheological evolution of an MFC scaffold to enable its use as a rheological modifier for consumer, fabric and home care products. MFC has a fiber size that is comparable to the fiber size of rheological modifiers in current use, but unlike other modifiers, MFC has negligible charge on the colloid. The potential advantages of MFC will be explored by characterizing the microstructural evolution of MFC using microrheology and microscopy, by characterizing the evolution of bulk rheology of MFC systems, and by determining equilibrium properties and scaffold structure after phase transitions using a unique microfluidic platform and multiple particle tracking microrheology. MFC solutions will be characterized during phase transitions due to three driving forces: temperature, changes in the surrounding solution and flow-induced mechanical forces. This knowledge will enable the use of these materials as rheological modifiers for the formulated product industry. The results of the research will identify materials that lead to homogeneous MFC suspensions and determine the microstructure and macroscopic structure and properties that lead to stable suspensions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.