Photopolymerized hydrogels are critical to soft devices, mechanobiology, regenerative medicine, and next generation drug delivery. However, the optimization of processing protocols for all of these applications of photopolymerized hydrogels has been at least semi-empirical due to the lack of a comprehensive predictive framework. Herein, we developed the first comprehensive predictive framework for how the chemical kinetics, optical properties, and mechanical properties of a photopolymerized hydrogel emerge from a precursor solution as the solution is illuminated, and of how these processing parameters relate to the final mechanics of the hydrogel. We validated the model experimentally using an eosin Y-initiated di-acrylate system. The model revealed that processing kinetics were dominated by photobleaching and crosslinking, and that network mechanics were dominated by chain growth and loop formation. We demonstrated the utility of the model by using it to design and then synthesize hydrogels with specified gradients in mechanical properties. The modeling framework is general and enables design of a broad range of hydrogels.

光聚合水凝胶对软设备，力学生物学，再生医学和下一代药物传递至关重要。然而，由于缺乏全面的预测框架，对于光聚合水凝胶的所有这些应用的处理方案的优化至少是半经验的。本文中，我们开发了第一个全面的预测框架，该框架适用于光聚合水凝胶在照射溶液时如何从前体溶液中产生的化学动力学，光学性质和机械性质，以及这些加工参数如何与水凝胶的最终力学相关。我们使用曙红Y引发的二丙烯酸酯系统通过实验验证了该模型。该模型表明，加工动力学受光漂白和交联作用的支配，网络机制主要由链增长和环路形成所主导。我们通过使用该模型设计并合成具有指定机械性能梯度的水凝胶，证明了该模型的实用性。建模框架是通用的，可以设计各种水凝胶。