# Poly (vinyl alcohol)/hydroxyapatite nanocomposite films with efficient adsorption and oil-water separation capabilities

## TL;DR

This paper develops PVA nanocomposite films with hydroxyapatite that can efficiently separate oil and water and adsorb substances like alcohol.

## Contribution

The study introduces a novel method to regulate composite film properties using HAPR and HAPW with different aspect ratios.

## Key findings

- PVA/HAPR and PVA/HAPW composite films show improved mechanical properties compared to pure PVA films.
- The optimized PVA/HAPW composite film has an adsorption capacity of 26.2 g/g for 1-Pentanol.
- The composite films have potential for scalable industrial oil-water separation applications.

## Abstract

This study used two adsorptive hydroxyapatite nanorods (HAPR) and hydroxyapatite nanowires (HAPW) as modifiers. HAPR and HAPW with different aspect ratios have different abilities to induce axial alignment of adjacent Poly (vinyl alcohol) (PVA) molecular chains as nucleation sites. Thus, they can regulate the comprehensive properties of the two composite films. Tensile curves show that the properties of the two composite films are optimal when the PVA/HAPR ratio is 25% and the PVA/HAPW ratio is 10%. Compared with pure PVA films, they are improved by 2.17 times and 1.62 times, respectively. In addition, the optimized PVA/HAPW composite film has an adsorption capacity of 26.2 g/g for 1-Pentanol. This is due to the microporous structure and surface groups constructed by HAPW. This study provides a new research idea for the preparation of PVA/HAPR and PVA/HAPW composite films with simple processes. It has potential scalability in the direction of achievable industrial oil-water separation materials.

Schematic diagrams at the top illustrate the preparation processes for HAPR and HAPW composites with PVA, displaying molecular interactions via hydrogen bonds. Below, two line charts show the stress versus strain performance of PVA composites containing various proportions of HAPR or HAPW, using color-coded lines to compare mechanical properties across samples.