Maddala Sai Prakash, Liao Wei-Chih, Joosten Rick R M, Soleimani Mohammad, Tuinier Remco, Friedrich Heiner, van Benthem Rolf A T M
Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry & Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
Center for Multiscale Electron Microscopy, Eindhoven University of Technology, Groene Loper 5, 5612 AE, Eindhoven, The Netherlands.
Commun Chem. 2021 Nov 19;4(1):160. doi: 10.1038/s42004-021-00595-y.
Polyamines play a major role in biosilicification reactions in diatoms and sponges. While the effects of polyamines on silicic acid oligomerization and precipitation are well known, the impact of polyamines chain length on silica particle growth is unclear. We studied the effects of polyamine chain length on silica particle growth and condensation in a known, simple, and salt-free biphasic reaction system; with tetraethyl orthosilicate as organic phase and polyamine dissolved in the aqueous phase. The particles at various growth stages were characterized by Cryo- Transmission Electron Microscopy, Scanning Electron Microscopy, Thermogravimetric Analysis, Zeta Potential, and solid-state NMR analysis. Polyamines were found co-localized within silica particles and the particle diameter increased with an increase in polyamine chain length, whereas silica condensation showed the opposite trend. Particle growth is proposed to progress via a coacervate intermediate while the final particles have a core shell structure with an amine-rich core and silica-rich shell. The results presented in this paper would of interest for researchers working in the field of bioinspired materials.
多胺在硅藻和海绵的生物硅化反应中起主要作用。虽然多胺对硅酸寡聚化和沉淀的影响是众所周知的，但多胺链长对二氧化硅颗粒生长的影响尚不清楚。我们在一个已知的、简单的、无盐的双相反应体系中研究了多胺链长对二氧化硅颗粒生长和缩合的影响；以原硅酸四乙酯为有机相，多胺溶解在水相中。通过低温透射电子显微镜、扫描电子显微镜、热重分析、zeta电位和固态核磁共振分析对不同生长阶段的颗粒进行了表征。发现多胺共定位在二氧化硅颗粒内，颗粒直径随着多胺链长的增加而增加，而二氧化硅缩合则呈现相反的趋势。提出颗粒生长通过凝聚层中间体进行，而最终颗粒具有核壳结构，核富含胺，壳富含二氧化硅。本文的研究结果将引起从事生物启发材料领域研究的人员的兴趣。
