کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
610370 880647 2009 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Wetting transition and optimal design for microstructured surfaces with hydrophobic and hydrophilic materials
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Wetting transition and optimal design for microstructured surfaces with hydrophobic and hydrophilic materials
چکیده انگلیسی

We present wetting transition of a water droplet on microstructured polymer surfaces using materials with different hydrophilicity or hydrophobicity: hydrophobic polydimethyl siloxane (PDMS) (θwater ∼ 110°) and hydrophilic Norland Optical Adhesive (NOA) (θwater ∼ 70°). The microstructures were fabricated by replica molding and self-replication with varying pillar geometry [diameter: 5 μm, spacing-to-diameter ratio (s/d): 1–10 (equal interval), height-to-diameter ratio (h/d): 1–5] over an area of 100 mm2 (10 mm × 10 mm). Measurements of contact angle (CA) and contact angle hysteresis (CAH) demonstrated that wetting state was either in the homogeneous Cassie regime or in the mixed regime of Cassie and Wenzel states depending on the values of s/d and h/d. These two ratios need to be adjusted to maintain stable superhydrophobic properties in the Cassie regime; s/d should be smaller than ∼7 (PDMS) and ∼6 (NOA) with h/d being larger than ∼2 to avoid wetting transition by collapse of a water droplet into the microstructure. Based on our observations, optimal design parameters were derived to achieve robust hydrophobicity of a microstructured surface with hydrophobic and hydrophilic materials.

The wetting transition and optimal design parameters to achieve robust superhydrophobicity are considered for microstructured polymer surfaces of hydrophobic and hydrophilic materials with varying spacing/diameter and height/diameter ratios.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 336, Issue 1, 1 August 2009, Pages 298–303
نویسندگان
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