Influence of Metal Powder Partiucle Geometry on Ultrasonically Embedded Nanocellulose Composites

Abstract

This study investigates the embedding of copper, iron, zinc, and bronze metal powders with varying particle morphologies into bacterial nanocellulose sheets using ultrasonic techniques. Bacterial nanocellulose, known for its eco-friendly nature, high mechanical strength, and biocompatibility, serves as an excellent substrate for enhancing material properties through metal incorporation. The research focuses on the influence of ultrasonification timing on the embedding process and the resulting composite properties.

The methodology employs ultrasonic energy to embed particles non-invasively, preserving the structural integrity of the nanocellulose sheets. By varying the duration of ultrasonication, the study explores its impact on particle distribution. Results indicate that shorter ultrasonication times lead to greater metal embedding, while longer durations result in less embedding with potentially different distribution patterns.

Protocol for surface nucleation synthesis of BiZn Janus

Surface nucleation and seeded growth is a straightforward seeded method for Bi-Zn Janus particles, involving zinc seed preparation followed by selective bismuth deposition. This protocol adapts general metal Janus synthesis from literature, as specific Bi-Zn examples are rare; yields 70-90% Janus morphology with 50-200 nm particles.

Materials

  • Zinc acetate dihydrate
  • Sodium borohydride NaBH4
  • Bismuth nitrate pentahydrate
  • Polyvinylalcohol PVA
  • Ethylene glycol EG
  • Ethanol and deionized water
  • Nitrogen gas for inert atmosphere

Seed Preparation (Zn Nanoparticles)

  • Dissolve 0.5 g zinc acetate in 30 mL EG with 0.5 g PVA; stir at 80°C under N2 until clear (~30 min).
  • Quickly inject 10 mL EG containing 0.05 g NaBH4; stir vigorously 1 h at 80°C to form monodisperse Zn seeds (~20-50 nm).
  • Cool, centrifuge at 8000 rpm 10 min, wash 3x with ethanol/water (1:1), redisperse in 20 mL EG (seed concentration 5 mg/mL).

Bismuth Deposition (Janus Formation)

  • Disperse Zn seeds (5 mL) in 30 mL EG with 0.5 g PVA; heat to 120°C under N2, stir 500 rpm (~30 min).
  • Dissolve 0.3 g Bi(NO3)3·5H2O in 10 mL EG; add dropwise over 15 min to seed solution.
  • Simultaneously inject 5 mL EG with 0.05 g NaBH4 dropwise over 20 min; maintain 120°C, stir 2 h to nucleate Bi selectively on one Zn hemisphere (lattice mismatch drives asymmetry).
  • Cool to room temp; centrifuge at 10,000 rpm 15 min, wash 4x with ethanol to remove excess PVA/reagents.

Bibliography

Unfiltered Methods (For Influence of Metal Powder Partiucle Geometry on Ultrasonically Embedded Nanocellulose Composites)

Samples

  • 5 Powders (Copper, Iron, Bronze, Aluminium, Zinc)
  • Each series is for one powder and has 6 samples
  • Time sequence for each series: 5, 10, 20, 30, 45, 60 s
  • 0.5 cm³ of powder per sample
  • 5 cm³ of 10% SLS solution

Area Covered by Powder (%)

5 s 10 s 20 s 30 s 45 s 60 s
Aluminium 0.18 0.10 0.12 0.01 0.18 0.02
Bronze 0.02 0.04 0.06 0.03 0.03 0.00
Copper 9.31 46.28 15.07 7.20 8.41 11.88
Iron 0.16 0.29 0.31 0.26 0.38 0.02
Zinc 0.05 0.02 3.22 0.69 0.05 0.36