Monolithic polymeric porous superhydrophobic material with pneumatic plastron stabilization for functionally durable drag reduction in blood-contacting biomedical applications

Jennifer Marlena,Justin Kok Soon Tan,Choon Hwai Yap,Boxin Zhao,Hwa Liang Leo,Sangho Kim,Zenggan Lin,David Xinzheyang Li

doi:10.1038/s41427-021-00325-9

Abstract

Superhydrophobic (SHP) surfaces can provide substantial reductions in flow drag forces and reduce blood damage in cardiovascular medical devices. However, strategies for functional durability are necessary, as many SHP surfaces have low durability under abrasion or strong fluid jetting or eventually lose their air plastron and slip-flow capabilities due to plastron gas dissolution, high fluid pressure, or fouling. Here, we present a functional material that extends the functional durability of superhydrophobic slip flow. Facile modification of a porous superhydrophobic polytetrafluoroethylene (PTFE, Teflon) foam produced suitable surface structures to enable fluid slip flow and resist protein fouling. Its monolithic nature offered abrasion durability, while its porosity allowed pressurized air to be supplied to resist fluid impalement and to replenish the air plastron lost to the fluid through dissolution. Active pore pressure control could resist high fluid pressures and turbulent flow conditions across a wide range of applied pressures. The pneumatically stabilized material yielded large drag reductions (up to 50%) even with protein fouling, as demonstrated from high-speed water jetting and closed loop pressure drop tests. Coupled with its high hemocompatibility and impaired protein adsorption, this easily fabricated material can be viable for incorporation into blood-contacting medical devices.

Highlights

IntroductionSuperhydrophobic (SHP) materials have received growing attention for their suitability to address these problems[7,8,9] by enabling fluid slip and reduction of fluid stresses and by preventing coagulation reactions
We have previously demonstrated the reduction in hemolysis with the use of a nearsuperhydrophobic surface through the reduction of fluid shear stresses with slip flow[53]
In this study, we presented a robust method of air plastron stabilization through active pneumatic air plastron control to oppose the fluid impalement pressure

Summary

Introduction

Superhydrophobic (SHP) materials have received growing attention for their suitability to address these problems[7,8,9] by enabling fluid slip and reduction of fluid stresses and by preventing coagulation reactions. SHP surfaces have low surface energies and textured surfaces that reduce flow friction and drag[7,10] to reduce stress-induced blood damage and hemolysis. Micro- or nanoscale surface asperities trap pockets of air (air plastrons), which reduce liquid-solid contact and the accompanying skin friction. This reduced contact manifests in a high water contact angle (>150°) and low roll-off angle (

Methods

Results

Conclusion