Wetting of Superhydrophobic Polylactic Acid Micropillared Patterns

Abstract

Superhydrophobic (SH) polylactic acid (PLA) surfaces were previously produced by various methods and used especially in biomedical applications and oil/water separation processes after 2008. However, the wettability of SH-PLA patterns containing micropillars has not been investigated before. In this study, PLA patterns having regular microstructured pillars with 12 different pillar diameters and pillar-to-pillar distances were prepared by hot pressing pre-flattened PLA sheets onto preformed polydimethylsiloxane (PDMS) soft molds having micro-sized pits. PDMS templates were previously prepared by photolithography using SU-8 molds. Apparent, advancing, and receding water contact angle measurements were carried out on the PLA patterns containing micropillars, and the morphology of the patterns was examined by optical and SEM microscopy. The largest contact angle obtained without the surface modification of the pure PLA pattern was 139°. Then, PLA micropatterns were hydrophobized using three types of silanes via chemical vapor deposition method, and SH-PLA patterns were obtained having θs of up to 167°. It was found that the highest θ values could be obtained when PLA pattern samples were coated with a silane containing a fluorine atom in its chemical structure. Washing and service life stability tests were also performed on the coated pattern samples and all of the silane coatings on the PLA patterns were found to be resistant over a 6 month period.

Revalorization of Yerba Mate Residues: Biopolymers-Based Films of Dual Wettability as Potential Mulching Materials

“…Layers can be considered hydrophilic, as all WCA values are below 90°. The PLA side of the bilayer film has a WCA of 73 + 1°, close to the 75–85° reported range [ 63 ]. However, the CH/TO-YCNF side is much more hydrophilic (WCA 53 + 2°).…”

Effect of Collector Rotational Speed on the Morphology and Structure of Solution Blow Spun Polylactic Acid (PLA)

“…As can be seen in the Figure 8 , all materials presented the similar water contact angle within the range of 125–130°. These results point out that when PLA is prepared in the form of nonwoven mats it behaves quite more hydrophobic than when PLA is prepared in the form of flat solid films with water contact angles lower than 80° [ 31 , 32 , 33 ]. This result can be explained considering that the higher the PLA surface available, the lower the water contact angle.…”

In Vivo Laser-Induced Vasoactive Microenvironmental Setting via a Stimuli-Responsive Microstructured Depot

“…The PTMFs were made using PLA biopolymer because PLA has been approved by the US Food and Drug Administration (FDA) for human use and has also demonstrated potential for the production of patterned films. , Due to its significant hydrophobic properties, this polymer is highly suitable for the effective packing and retention of low-molecular-weight substances. , Our previous research has demonstrated that PLA microchamber arrays exhibit excellent resistance to mechanical deformation and better retention of FITC-dextran and Solumedrol (methylprednisolone sodium succinate) in saline solution than other hydrophobic polymers such as PLGA and PCL …”