Preparation of Polyethylene/α-Zirconium Phosphate Nanocomposites via a Well-Controlled Polyethylene-Grafted Interface.

It is a daunting task to prepare polyolefin nanocomposites that contain well-exfoliated nanoplatelets due to the nonpolar and high crystallinity nature of polyolefins. In this research, a robust approach was developed to prepare polyethylene (PE) nanocomposites by grafting maleated polyethylene (MPE) onto pre-exfoliated α-zirconium phosphate (ZrP) nanoplatelets via a simple amine-anhydride reaction to form ZrP--MPE. Several variables, including maleic anhydride (MA) content, MPE graft density, MPE molecular weight, and PE matrix crystallinity, were investigated to determine how they influence ZrP--MPE dispersion in PE.

Preparation of Well-Exfoliated Poly(ethylene--vinyl acetate)/α-Zirconium Phosphate Nanocomposites.

Poly(ethylene--vinyl acetate) (PEVAc) nanocomposites containing exfoliated α-zirconium phosphate (ZrP) have been prepared using a simple solution mixing method to improve their barrier and mechanical properties. ZrP was pre-exfoliated with a surfactant, followed by additional targeted surface functionalization and surfactant exchange to allow for hydrogen bonding of ZrP with the acetate functionality on PEVAc and to improve ZrP surface hydrophobicity. The solvent is found to play an important role in stabilizing ZrP exfoliation in the presence of PEVAc to retain full exfoliation and homogeneous dispersion upon the removal of the solvent.

XFinger-Net: Pixel-Wise Segmentation Method for Partially Defective Fingerprint Based on Attention Gates and U-Net.

Partially defective fingerprint image (PDFI) with poor performance poses challenges to the automated fingerprint identification system (AFIS). To improve the quality and the performance rate of PDFI, it is essential to use accurate segmentation. Currently, most fingerprint image segmentations use methods with ridge orientation, ridge frequency, coherence, variance, local gradient, etc.