Porous Waterborne Polyurethane Films Templated from Pickering Foams for Fabrication of Synthetic Leather

Waterborne polyurethane (WPU) latex nanoparticles with proven interfacial activity were utilized to stabilize air–water interfaces of Pickering foams through interfacial interaction with hydrophobic fumed silica particles (SPs). The rheological properties of the Pickering foam were tailored through adjustment of their SP content, which influenced their formability and stability. A Pickering foam stabilized with WPU and SPs was used as a template to prepare a WPU–SP composite porous film. The as-prepared film had intact open-cell porous structures, which increased its water absorption and water-vapor permeability. The porous film was used as a middle layer in the preparation of synthetic leather via a four-step “drying method”. Compared with commercial synthetic leather, the lab-made synthetic leather with a middle layer made of the WPU–SP composite porous film exhibited a richer porous structure, acceptable wetting on a fabric substrate, a thicker porous layer, and higher water-vapor permeability. This work provides a novel and facile approach for preparing WPU–SP Pickering foams. Furthermore, the foams have the potential to function as a sustainable material for creating a porous-structured synthetic leather made from WPU, which may be utilized as an alternative to solvent-based synthetic leather

Results of PET/CT image registration.

<p>(a) CT image; (b) PET image at the same position; (c) results of image registration.</p

Accuracy of pulmonary nodules segmentation.

<p>APNSL: average pixels of segmented lesions; PNSLM: pixels in segmented lesions based on the manual; ONPMS: number of overlapping pixels with manual segmentation; SAR: accuracy of segmentation.</p><p>Accuracy of pulmonary nodules segmentation.</p

Results of nodule segmentation in different PET/CT images.

<p>(a-1, -2, and 3) CT images; (b-1, -2, and 3) corresponding PET images; (c-1, -2, and 3) results of segmentation.</p

Non-nodules correctly detected based on the proposed method.

<p>Non-nodules correctly detected based on the proposed method.</p

Characteristics of nodules and non-nodules.

<p>Characteristics of nodules and non-nodules.</p

Segmentation as produced by the proposed method.

<p>(a) original image; (b) results of segmentation; (c) binarized lung parenchyma.</p

Comparison of the traditional methods based on SVM.

<p>Comparison of the traditional methods based on SVM.</p

Segmentation results of suspicious nodules in CT images.

<p>(a-1, -2, and 3) suspicious nodule areas; (b-1, -2, and 3) suspicious nodules evaluated by a dynamic threshold segmentation method; (c-1, -2, and 3) show the resulting outer rectangle templates; (d-1, -2, and 3) show the suspicious nodules with the outer rectangles.</p

Sensitivity and false-positives for traditional and proposed methods.

<p>Sensitivity and false-positives for traditional and proposed methods.</p