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Research Series
Growth on pristine surfaces
CaCO 3 on steel
BaSO 4 on steel
Growth on pre-fouled surfaces
CaCO 3 on BaSO 4
BaSO 4 on CaCO 3
Figure 2 . The order in which foulants grow is crucial . The figure shows an example where BaSO 4 promotes CaCO 3 growth , while CaCO 3 promotes detachment of BaSO 4
. See more in [ 3 ]
Notable techniques within surface engineering include magnetic coatings , hydrophobic coatings , and patterned surfaces . Liquid-infused surfaces ( LISs ) are biomimetic coatings known for their remarkable antifouling properties [ 4 ] . Nevertheless , the primary challenge lies in ensuring durability , as the coatings tend to degrade over time during operation . In response to this challenge , researchers have created resilient ferromagnetic coatings with a liquid-liquid interface . These coatings drastically reduced deposition rates and promoted easy detachment with increased shear stress . To further enhance longevity , these coatings have been seamlessly integrated into a gel structure [ 5 ] . Another innovative nature-inspired surface modification is referred to as the lotus flower effect . The lotus flower has a fractal-like surface structure , wherein each protrusion on the surface is replicated on a progressively smaller scale . This intricate arrangement results in a superhydrophobic surface . This hydrophobic nature gives rise to a selfcleaning effect , rendering it more challenging for weakly adhering crystals to persist on the surface . Researchers have demonstrated that surfaces featuring numerous small curvy features outperformed those with protruded or inverted squared patterns in mitigating scaling issues [ 6 ] . This pattern was found to enhance detachment events , primarily attributed to the presence of heightened local shear stress . While surface engineering provides many benefits , challenges such as cost , durability , and potential environmental impact remain . Current ongoing research is dedicated to the pursuit of environmentally friendly , enduring , and cost-effective antifouling strategies .
The way forward Surfaces play a pivotal role in fouling processes . However , many existing models fall short in capturing the complexities arising from the dynamic behavior of surfaces . Prediction errors can lead to expensive design errors . For instance , an overestimation of the surface area in a heat exchanger can significantly inflate the price of the unit . Therefore , models that can illuminate how fouling modes and surfaces intersect and influence each other are needed . To advance our understanding and enhance model development , further experimental research is imperative . Research studies should focus on unraveling the adhesive interactions that arise from the interplay of diverse surfaces and fouling modes . With a deeper understanding of fouling , we can develop more effective strategies to combat it . Surface modifications through coatings and surface patterning present promising opportunities . As scientific exploration continues , we can expect to develop even more innovative solutions to fouling .
References
[ 1 ] Keysar , S . et al . ( 1994 ) ‘ Effect of surface roughness on the morphology of calcite crystallizing on mild steel ’, Journal of Colloid and Interface Science , 162 ( 2 ), pp . 311 – 319 . doi : 10.1006 / jcis . 1994.1044 .
[ 2 ] Løge , I . A . et al . ( 2022 ) ‘ Scale attachment and detachment : The role of Hydrodynamics and surface morphology ’, Chemical Engineering Journal , 430 , p . 132583 . doi : 10.1016 / j . cej . 2021.132583 .
[ 3 ] Løge , I . A ., Anabaraonye , B . U . and Fosbøl , P . L . ( 2022 ) ‘ Growth mechanisms of composite fouling : The impact of substrates on detachment processes ’, Chemical Engineering Journal , 446 , p . 137008 . doi : 10.1016 / j . cej . 2022.137008 .
[ 4 ] Villegas , M . et al . ( 2019 ) ‘ Liquid-infused surfaces : A review of theory , design , and applications ’, ACS Nano , 13 ( 8 ), pp . 8517 – 8536 . doi : 10.1021 / acsnano . 9b04129 .
[ 5 ] Masoudi , A . et al . ( 2017 ) ‘ Antiscaling magnetic slippery surfaces ’, ACS Applied Materials & amp ; Interfaces , 9 ( 24 ), pp . 21025 – 21033 . doi : 10.1021 / acsami . 7b05564 .
[ 6 ] Pääkkönen , T . M . et al . ( 2013 ) ‘ Surface patterning of stainless steel in prevention of fouling in heat transfer equipment ’, Materials Science Forum , 762 , pp . 493 – 500 . doi : 10.4028 / www . scientific . net / msf . 762.493 .
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