Research Center for Bio-based Chemistry, Korea Research Institute of Chemical Technology (KRICT), Ulsan, 44429, Republic of Korea.
Department of Polymer Engineering, Pukyong National University, Busan, 48513, Republic of Korea.
Adv Mater. 2020 Mar;32(11):e1907064. doi: 10.1002/adma.201907064. Epub 2020 Feb 5.
Perishable foods at undesired temperatures can generate foodborne illnesses that present significant societal costs. To certify refrigeration succession in a food-supply chain, a flexible, easy-to-interpret, damage-tolerant, and sensitive time-temperature indicator (TTI) that uses a self-healing nanofiber mat is devised. This mat is opaque when refrigerated due to nanofiber-induced light scattering, but becomes irreversibly transparent at room temperature through self-healing-induced interfibrillar fusion leading to the appearance of a warning sign. The mat monitors both freezer (-20 °C) and chiller (2 °C) successions and its timer is tunable over the 0.5-22.5 h range through control of the polymer composition and film thickness. The thin mat itself serves as both a temperature sensor and display; it does not require modularization, accurately measures localized or gradient heat, and functions even after crushing, cutting, and when weight-loaded in a manner that existing TTIs cannot. It also contains no drainable chemicals and is attachable to various shapes because it operates through an intrinsic physical response.
在不理想温度下的易腐食品可能会产生食源性疾病，给社会带来巨大成本。为了在食品供应链中确保冷藏的连续性，设计了一种灵活、易于解释、耐损伤和敏感的时间-温度指示器（TTI），它使用自修复纳米纤维垫。由于纳米纤维引起的光散射，这种垫子在冷藏时是不透明的，但在室温下通过自修复引起的纤维间融合会变得不可逆透明，从而出现警告标志。垫子可以监测冷冻器（-20°C）和冷藏器（2°C）的连续性，其定时器可以通过控制聚合物组成和薄膜厚度在 0.5-22.5 小时范围内进行调整。这种薄垫子本身既是温度传感器又是显示器；它不需要模块化，能够准确测量局部或梯度热，即使在被压碎、切割以及以现有 TTI 无法实现的方式加载重量时也能正常工作。它还不含有毒化学物质，因为它通过内在的物理响应来工作，所以可以附着在各种形状上。
