Drying and cracking of soft latex coatings
Drying and cracking of soft latex coatings
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软乳胶涂料的干燥和开裂
DOI：
10.1007/s11998-012-9425-7
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发表时间：
2013
影响因子：
2.3
通讯作者：
L. Francis
中科院分区：
文献类型：
--
作者：
C. Roberts;L. Francis
最低成膜温度（MFFT）是乳胶涂料聚结成光学透明、致密、无裂纹的膜所需的最低干燥温度。为了更好地理解在该临界温度附近的力的相互作用，使用低温扫描电子显微镜（cryoSEM）来跟踪在刚好高于和低于MFFT的温度下干燥的涂层中的胶乳颗粒变形和水迁移。尽管在干燥过程结束时胶乳颗粒在两个温度下完全聚结，但发现在早期干燥阶段期间的颗粒变形显著不同。在MFFT以下，裂纹开始时，就像Al_2O_3开始退入固结颗粒的堆积中，而在MFFT以上，部分颗粒变形发生在Al_2O_3进入涂层之前，没有观察到裂纹。在不同温度下干燥的涂层中测得的裂纹之间的间距随着干燥温度的降低而降低，而在临界温度以下则与温度无关。最后，添加少量的二氧化硅聚集体被发现，以减少附近的MFFT的胶乳涂层的开裂，而不会对它们的光学透明度产生不利影响。
The minimum film formation temperature (MFFT) is the minimum drying temperature needed for a latex coating to coalesce into an optically clear, dense crack-free film. To better understand the interplay of forces near this critical temperature, cryogenic scanning electron microscopy (cryoSEM) was used to track the latex particle deformation and water migration in coatings dried at temperatures just above and below the MFFT. Although the latex particles completely coalesced at both temperatures by the end of the drying process, it was discovered that particle deformation during the early drying stages was drastically different. Below the MFFT, cracks initiated just as menisci began to recede into the packing of consolidated particles, whereas above the MFFT, partial particle deformation occurred before menisci entered the coating and cracks were not observed. The spacing between cracks measured in coatings dried at varying temperatures decreased with decreasing drying temperature near the MFFT, whereas it was independent of temperature below a critical temperature. Finally, the addition of small amounts of silica aggregates was found to lessen the cracking of latex coatings near the MFFT without adversely affecting their optical clarity.
DOI：
10.1021/la904512q
发表时间：
2010-02
期刊：
Langmuir : the ACS journal of surfaces and colloids
影响因子：
--
作者：
K. Dragnevski;A. Routh;Martin W. Murray;A. Donald
通讯作者：
K. Dragnevski;A. Routh;Martin W. Murray;A. Donald