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Updated: Jan 10, 2026

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
Salt ions can control supraparticle structure during spray-drying of colloids, but they affect functionality-Volatile
Andreas Zink1, Sebastian Kolb1, Susanne Wintzheimer2
1Department of Chemistry and Pharmacy, Section Materials Chemistry, Chair Particle-Based Materials Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, D-91058 Erlangen, Germany.
None:
Salts were found to be useful in order to manipulate the structure formation and shaping of supraparticles during spray-drying. However, commonly utilized salts such as calcium chloride (CaCl2) remain in the framework of the supraparticles and thus, potentially interfere with the properties of the supraparticles. In this study, ammonium carbonate ((NH4)2CO3) is introduced as a structure-directing agent and compared to CaCl2. Due to its thermal decomposability into gaseous species, (NH4)2CO3 can be completely post-synthetically removed by a simple heat treatment. Thus, undesired washing steps of the supraparticle products are avoided and interferences of the salt with the functional properties of supraparticles are eliminated. These advantages are highlighted for the example of hydrogen-indicating gasochromic supraparticles. In summary, (NH4)2CO3 acts as a structure-directing agent without affecting the intrinsic properties of the supraparticles, making it suitable for applications in systems where residual salt is undesired.
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