Sara K. Fleetwood

• Bachelor of Science
• PhD Student at University of British Columbia

This study analyzes and evaluates the use of cellulose nanocrystals (CNCs), stiff nano-sized, natural materials that have been modified to mimic heparin. These CNCs are simple polysaccharides with a similar backbone structure to heparin, that when modified reduce coagulation and potentially the long-term effects of solution-based anticoagulants. Th...

Deciduous broad-leaf trees survive and prepare for winter by shedding their leaves in fall. During the fall season, a change in a leaf’s wettability and its impact on the leaf-fall are not well understood. In this study, we measure the surface morphology and wettability of Katsura leaves from the summer to winter, and reveal how leaf structural cha...

[This corrects the article DOI: 10.1371/journal.pone.0202900.].

The areal fraction of intact wax regions is measured by using the contrast difference. We ignored intact wax regions of less than 5 μm2 and eroded wax regions of less than 22.5 μm2 when measuring the α value. (a) The schematic of a brown leaf depicts how the wax-coated and eroded regions are located from the side view. (b) A top-viewed SEM image of...

The cross-sectional ESEM images of leaves after various treatments:(a) green, (b) brown, (c) heat-treated, (d) vacuum-treated leaves. The surface roughness has been measured from the blue lines extracted from a customized Matlab code. (PDF)

Contact angle vs. heating-time plots for several oven temperatures. As the epicuticular wax tubules melt away due to the heat, the contact angle decreases. (a) The epicuticular wax tubules did not significantly melt even after 20 hours at 55°C. (b) At 65°C, the wax starts to disappear after 1 hour. (c) Most of the wax tubules melted away after 1 ho...

The areal fraction of liquid/solid interface is evaluated from ESEM images by tracking liquid/solid interface. To determine ϕnano, the image histogram was used to choose a reliable and systematic parameter in the grayscale. Typically, two peaks were observed in the histogram as shown in the inset of S4 Fig (a). First, the region brighter than the u...

To measure the efficiency of a solar cell, we placed a halogen lamp (200W, 120V, LOWEL PRO) at 70 cm from the solar cell. (a) An uncoated solar cell (GP80 × 80-10A 100, sunnytech) has a hydrophilic surface (63.66 ± 2.44°) and performs Voc = 5.73 ± 0.14 V, Isc = 98.44 ± 1.88 mA, Pmax = 0.56 ± 0.02 W, where Isc is the short-circuit current, Voc is th...

Schematics of the procedure to experimentally visualize the liquid/solid interface on epidermal cells using environmental scanning electron microscopy (ESEM). (a) A water droplet is placed on the Katsura leaf. (b) We then freeze the water droplet by rapidly decreasing the temperature using liquid nitrogen. There is 9% volume expansion when the phas...

(a) 10 ml chloroform was dripped onto a green Katsura leaf which was tilted at about 30 degrees from the horizontal axis. Then, the collected wax-dissolved chloroform solution was coated on a target substrate and gently dried with nitrogen gas. (b) An SEM image of the flat wax-coated substrate. The inset shows an optical image of the wax-coated sil...

Top and cross-sectional SEM images of leaves with various treatments: (a) A heat-treated Katsura leaf shows shrunken epidermal cells and melted epicuticular waxes. (b) A vacuum dried procedure preserves epiculticular waxes, but makes the cells shrink. (c) Chloroform treatment removed only the epicuticular wax. The epidermal cells were intact from t...

Combined Wenzel and Cassie-Baxter model. The expression of the apparent contact angle by finding the equilibrium state of surface energies at the three-phase contact line. (PDF)