Li Gen, Varga Imre, Kardos Attila, Dobryden Illia, Claesson Per M
School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Chemistry, Division of Surface and Corrosion Science, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden.
Institute of Chemistry, Eötvös Loránd University, Pázmány P. s. 1/A, 1117 Budapest, Hungary.
Langmuir. 2021 Feb 9;37(5):1902-1912. doi: 10.1021/acs.langmuir.0c03386. Epub 2021 Jan 27.
The temperature dependence of nanomechanical properties of adsorbed poly-NIPAm microgel particles prepared by a semibatch polymerization process was investigated in an aqueous environment via indentation-based atomic force microscopy (AFM) methods. Poly-NIPAm microgel particles prepared by the classical batch process were also characterized for comparison. The local mechanical properties were measured between 26 and 35 °C, i.e., in the temperature range of the volume transition. Two different AFM tips with different shapes and end radii were utilized. The nanomechanical properties measured by the two kinds of tips showed a similar temperature dependence of the nanomechanical properties, but the actual values were found to depend on the size of the tip. The results suggest that the semibatch synthesis process results in the formation of more homogeneous microgel particles than the classical batch method. The methodological approach reported in this work is generally applicable to soft surface characterization in situ.
通过基于压痕的原子力显微镜（AFM）方法，在水性环境中研究了通过半间歇聚合工艺制备的吸附聚N-异丙基丙烯酰胺（poly-NIPAm）微凝胶颗粒的纳米力学性能的温度依赖性。还对通过经典间歇工艺制备的聚N-异丙基丙烯酰胺微凝胶颗粒进行了表征以作比较。在26至35°C之间测量局部力学性能，即在体积转变的温度范围内进行测量。使用了两种具有不同形状和端部半径的不同AFM探针。由这两种探针测量的纳米力学性能显示出相似的纳米力学性能温度依赖性，但发现实际值取决于探针的尺寸。结果表明，与经典间歇法相比，半间歇合成工艺导致形成更均匀的微凝胶颗粒。这项工作中报道的方法通常适用于原位软表面表征。
