PAA-PAMPS Copolymers as an Efficient Tool to Control CaCO3 Scale Formation

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• 作者：Michael Dietzsch ; Matthias Barz ; Timo Sch眉ler ; Stefanie Klassen ; Martin Schreiber ; Moritz Susewind ; Niklas Loges ; Michael Lang ; Nadja Hellmann ; Monika Fritz ; Karl Fischer ; Patrick Theato ; Angelika K眉hnle ; Manfred Schmidt ; Rudolf Zentel ; Wolfgang Tremel
• 刊名：Langmuir
• 出版年：2013
• 出版时间：March 5, 2013
• 年：2013
• 卷：29
• 期：9
• 页码：3080-3088
• 全文大小：507K
• 年卷期：v.29,no.9(March 5, 2013)
• ISSN：1520-5827

文摘

Scale formation, the deposition of certain minerals such as CaCO₃, MgCO₃, and CaSO₄路2H₂O in industrial facilities and household devices, leads to reduced efficiency or severe damage. Therefore, incrustation is a major problem in everyday life. In recent years, double hydrophilic block copolymers (DHBCs) have been the focus of interest in academia with regard to their antiscaling potential. In this work, we synthesized well-defined blocklike PAA-PAMPS copolymers consisting of acrylic acid (AA) and 2-acrylamido-2-methyl-propane sulfonate (AMPS) units in a one-step reaction by RAFT polymerization. The derived copolymers had dispersities of 1.3 and below. The copolymers have then been investigated in detail regarding their impact on the different stages of the crystallization process of CaCO₃. Ca²⁺ complexation, the first step of a precipitation process, and polyelectrolyte stability in aqueous solution have been investigated by potentiometric measurements, isothermal titration calorimetry (ITC), and dynamic light scattering (DLS). A weak Ca²⁺ induced copolymer aggregation without concomitant precipitation was observed. Nucleation, early particle growth, and colloidal stability have been monitored in situ with DLS. The copolymers retard or even completely suppress nucleation, most probably by complexation of solution aggregates. In addition, they stabilize existing CaCO₃ particles in the nanometer regime. In situ AFM was used as a tool to verify the coordination of the copolymer to the calcite (104) crystal surface and to estimate its potential as a growth inhibitor in a supersaturated CaCO₃ environment. All investigated copolymers instantly stopped further crystal growth. The carboxylate richest copolymer as the most promising antiscaling candidate proved its enormous potential in scale inhibition as well in an industrial-filming test (Fresenius standard method).