We present findings on the influence of gamma radiation on the crack pattern of dried drops of an aqueous styrene-acrylic emulsion. An increase in the dose of gamma radiation reduces the number of cracks and expands the edge of the dried droplet. Furthermore, gamma radiation induces a reduction in the branching of the crack pattern and an increase in the frequency of cracks, with a magnitude comparable to the width of the edge of the dried droplet. The results of the infrared analysis indicated that the micelles surrounding the styrene-acrylic copolymer in the emulsion exerted a protective effect, preventing indirect damage caused by radicals formed due to water radiolysis. The results of the zeta potential and particle size measurements demonstrated that gamma radiation caused an increase in the average size of the micelles, a widening of the size distribution, and a redistribution of surface charges. Doses above 100 kGy induce a loss of emulsion stability. The effects of gamma radiation on the crack patterns were interpreted by considering the dynamics of micelle deposition at the edge of the drop during drying and the appearance of mechanical instabilities in the deposit that lead to cracks. The larger micelles produced due to gamma radiation on the emulsion modify the microstructure formation at the edge of the dried drop, thereby alleviating the formation of mechanical stresses that result in the appearance of cracks.

中文翻译：

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伽马辐射对苯丙乳液干滴裂纹模式的影响


我们提出了伽马辐射对苯乙烯-丙烯酸水乳液干滴裂纹模式的影响的研究结果。伽马辐射剂量的增加减少了裂纹的数量并扩大了干燥液滴的边缘。此外，伽马辐射会导致裂纹图案分支的减少和裂纹频率的增加，其幅度与干燥液滴边缘的宽度相当。红外分析结果表明，乳液中苯乙烯-丙烯酸共聚物周围的胶束发挥了保护作用，防止水辐射分解形成的自由基造成的间接损伤。 Zeta 电位和粒径测量结果表明，伽马辐射导致胶束平均尺寸增加、尺寸分布变宽以及表面电荷重新分布。超过 100 kGy 的剂量会导致乳液稳定性丧失。通过考虑干燥过程中液滴边缘胶束沉积的动力学以及沉积物中导致裂纹的机械不稳定性的出现，解释了伽马辐射对裂纹图案的影响。由于乳液上的伽马辐射而产生的较大胶束改变了干燥液滴边缘处的微结构形成，从而减轻了导致裂纹出现的机械应力的形成。