Micro-/Nanoscale Approach for Studying Scale Formation and Developing Scale-Resistant Surfaces

Hossein Sojoudi; Srinivasa Kartik Nemani; Kaitlyn M Mullin; Matthew G Wilson; Hamad Aladwani; Haitham Lababidi; Karen K Gleason

doi:10.1021/acsami.8b18523

Micro-/Nanoscale Approach for Studying Scale Formation and Developing Scale-Resistant Surfaces

ACS Appl Mater Interfaces. 2019 Feb 20;11(7):7330-7337. doi: 10.1021/acsami.8b18523. Epub 2019 Feb 8.

Authors

Hossein Sojoudi¹, Srinivasa Kartik Nemani¹, Kaitlyn M Mullin², Matthew G Wilson², Hamad Aladwani³, Haitham Lababidi³, Karen K Gleason²

Affiliations

¹ Department of Mechanical, Industrial, and Manufacturing Engineering , University of Toledo , 2801 W. Bancroft Street , Toledo , Ohio 43606 , United States.
² Department of Chemical Engineering , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States.
³ Department of Chemical Engineering, College of Engineering & Petroleum , Kuwait University , P.O. Box 5969, 13060 Safat , Kuwait.

PMID: 30689336
DOI: 10.1021/acsami.8b18523

Abstract

Blockage of pipelines due to accretion of salt particles is detrimental in desalination and water-harvesting industries as they compromise productivity, while increasing maintenance costs. We present a micro-/nanoscale approach to study fundamentals of scale formation, deposition, and adhesion to engineered surfaces with a wide range of surface energies fabricated using the initiated chemical vapor deposition method. Silicon wafers and steel substrates are coated with poly(1 H,1 H,2 H,2 H-perfluorodecylacrylate) or pPFDA, poly(tetravinyl-tetramethylcyclotetrasilohexane) or pV4D4, poly(divinylbenzene) or pDVB, poly(1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasilohexane) or pV3D3, and cross-linked copolymers of poly(2-hydroxyethylmethacrylate) and poly(ethylene glycol) diacrylate or p(PHEMA- co-EGDA). Particles of salt (CaSO₄·2H₂O) are formed and shaped with a focused ion beam and adhered to a tipless cantilever beam using a micromanipulator setup to study their adhesion strength with a molecular force probe (MFP). Adhesion forces were measured on the substrates in wet and dry conditions to evaluate the effects of interfacial fluid layers and capillary bridges on net adhesion strength. The adhesion between salt particles and the pPFDA coatings decreased by 5.1 ± 1.15 nN in wet states, indicating the influence of capillary bridging between the particle and the liquid layer. In addition, scale nucleation and growth on various surfaces is examined using a quartz crystal microbalance (QCM), where supersaturated solution of CaSO₄·2H₂O is passed over bare and polymer-coated quartz substrates while mass gain is measured in real time. The salt accretion decreased by 2 folds on pPFDA-coated substrates when compared to that on p(HEMA- co-EGDA) coatings. Both MFP and QCM studies are essential in studying the impact of surface energy and roughness on the extent of scale formation and adhesion strength. This study can pave way for the design of scale-resistant surfaces with potential applications in water treatment, energy harvesting, and purification industries.

Keywords: MFP; QCM; adhesion; iCVD polymer coatings; scaling; surface energy.