Controlling the fragrance release profile, especially the highly volatile top note, can prolong the desired scent of the fragrance. Here, the porosity of a swollen cross‐linked polyurethane acrylate (PUA) polymer, which is tuned by the length of a modulator, can influence the evaporation rate of the top note. In particular, the evaporation rate of benzyl acetate (BA), a common top note, is reduced by a factor of 6.5 (from 134 to 17 mg m^–2 min^–1) when BA is released from the best‐performing PUA against a reservoir of BA. The average diameter of an opening in the fragrance‐loaded PUA is ~6 nm, as determined by the thermoporosimetry approach. Such a pore size can effectively control the evaporation rate of BA, as predicted by the theoretical model, which reveals that a pore diameter of <16 nm is required. Computational modelling reveals the optimal chain length for a modulator used for the sustained released of fragrance, confirming the experimental data. Finally, BA continues to be released from the PUA matrix for a prolonged period, even after 3 months, whereas the same quantity of BA would completely evaporate after 1 week in the absence of PUA matrix. Approximately 50wt% of BA remains after 60 days, making it one of the best techniques in sustaining the release of a top note.

中文翻译：

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设计溶胀聚合物中的纳米孔隙度，以控制释放高挥发性香精

控制香料的释放曲线，尤其是高度挥发性的头香，可以延长所需的香料香气。在此，溶胀的交联聚氨酯丙烯酸酯（PUA）聚合物的孔隙度（取决于调制剂的长度）会影响头香的蒸发速率。尤其是，通常注意到的乙酸苄酯（BA）的蒸发速率降低了6.5倍（从134降至17 mg m ^–2  min ^–1），当BA从性能最佳的PUA释放到BA的存储库中时。通过热孔隙率法测定，在装有香料的PUA中，开口的平均直径约为6 nm。如理论模型所预测的，这样的孔径可以有效地控制BA的蒸发速率，这表明需要<16 nm的孔径。计算模型揭示了用于香料的持续释放的调节剂的最佳链长，证实了实验数据。最终，即使在3个月后，BA仍会长时间从PUA基质中释放出来，而在没有PUA基质的情况下，相同量的BA将在1周后完全蒸发。60天后约有50wt％的BA残留，这使其成为维持头香释放的最佳技术之一。