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

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(1H,1H,2H,2H-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 (CaSO 4 •2H 2 O) 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 CaSO 4 •2H 2 O 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.

On Coating Techniques for Surface Protection: A Review

“…Another type of vapor deposition is called CVD. This process undergoes a high vacuum and is widely used in the semiconductors industry providing a solid, high quality, and a high resistance coating layer on any substrate [19][20][21][22]. CVD can be used for mechanical parts in constant contact, which need protection against corrosion and wear.…”

Advanced Antiscaling Interfacial Materials toward Highly Efficient Heat Energy Transfer

“…For example, by using gold‐coated Si 3 N 4 tips modified with various thiol molecules (Figure C), the mean adhesion force between Au:S(CH 2 ) 10 COO − modified tip and calcium oxalate monohydrate with exposed (100) crystal face was 4.28 ± 0.62 nN, which was approximately five times of the value for Au:S(CH 2 ) 10 CH 2 OH (0.83 ± 0.33 nN) and Au:S(CH 2 ) 10 CH 3 (0.66 ± 0.17 nN). On the other, to study their adhesion strength, the shaped particles of crystals (e.g., CaSO 4 ·2H 2 O) were adhered to a tipless cantilever beam using a micromanipulator setup (Figure D) . For example, Gleason observed that polymer coatings with lower polar components of surface energies exhibited lower adhesion strengths.…”

“…For example, Gleason observed that polymer coatings with lower polar components of surface energies exhibited lower adhesion strengths. Compared with polymer coatings such as poly(1,3,5,7‐tetravinyl‐1,3,5,7‐tetrame‐thylcyclotetrasilohexane) (pV 3 D 3 ), poly(tetravinyl‐tetrame‐thylcyclotetrasilohexane) (pV 4 D 4 ), poly(divinylbenzene) (pDVB), and copolymer of poly(2‐hydroxyethylmethacrylate) and polyethylene glycol diacrylate (pHEMA‐co‐pEGDA), poly(1 H ,1 H ,2 H ,2 H ‐perfluorodecyl acrylate) (pPFDA)‐coated substrates showed the lowest salt adhesion forces of 11.1 ± 1.6 and 6.0 ± 2.75 nN in dry and wet states, respectively . This result indicates the effect of polar components of surface energies on developing efficient scale‐resistant engineered surfaces.…”

“…AFM has been used extensively for direct measurement of adhesion forces between fouling materials and solid surfaces. Significantly, it can be used to directly measure adhesion forces between functional molecules decorated AFM tips and selected crystal faces, and those between crystal‐adhered cantilever and substrates . On the one hand, to identify the combinations of adhesive functional group and crystal faces, decorated AFM tips (e.g., organosulfur molecule) were brought into contact with selected crystals and even its particular crystal face .…”

Scale Deposition Inhibiting Composites by HDPE/Silicified Acrylate Polymer/Nano-Silica for Landfill Leachate Piping

“…The pipe scale formation is considered as a joint reaction between the leachate and piping materials [ 5 ]. To mitigate clogging consequences, conventional engineering measures have mainly focused on pipe cleaning, including aeration in the pipeline [ 6 ], adjustment of hydraulic loading [ 7 ], high-pressure water jetting [ 8 ], addition of scale inhibitors [ 9 ], etc.…”