Biodegradable shape memory nanocomposites with thermal and magnetic field responsiveness.

Abstract

Thermal and magnetic field responsive biodegradable shape memory polymer nanocomposite was prepared with Fe3O4 nanoparticles and poly(L-lactides) (PLLA). The magnetic Fe3O4 nanoparticles with an average size of 9 nm were initially synthesized by co-precipitation method and then followed by surface modification using oleic acid. The TEM and SEM results show that the surface modified Fe3O4 nanoparticles can evenly disperse in chloroform and PLLA polymer matrix. The tensile test results show that the addition of Fe3O4 nanoparticles to a PLLA matrix greatly improved the elastic modulus, tensile strength, elongation at break, and the shape memory properties as well. Moreover, the shape recovery process of the nanocomposites driven by an alternating magnetic field was also observed. However, the shape recovery ratio and the recovery speed in an alternating magnetic field are lower than that occurred in 70 °C water. The lower shape recovery ratio and the recovery speed in an alternating magnetic field is attributed to the low frequency and strength of the magnetic field, which lead to small heat generated by Fe3O4 nanoparticles.

AI evidence extraction

Main findings

A biodegradable shape memory PLLA nanocomposite containing surface-modified Fe3O4 nanoparticles was prepared and showed improved mechanical properties and shape memory properties versus PLLA. Shape recovery driven by an alternating magnetic field was observed, but the recovery ratio and speed under the alternating magnetic field were lower than in 70C water; this was attributed to low frequency/strength of the magnetic field producing limited heating.

Outcomes measured

• Shape recovery (shape memory behavior)
• Mechanical properties (elastic modulus, tensile strength, elongation at break)
• Nanoparticle dispersion (TEM/SEM)

Limitations

• No magnetic field parameters (frequency/field strength) are provided in the abstract.
• No quantitative results are provided in the abstract for mechanical or shape recovery outcomes.
• No sample size or number of specimens is reported in the abstract.

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    "study_type": "engineering",
    "exposure": {
        "band": null,
        "source": "alternating magnetic field",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "Shape recovery (shape memory behavior)",
        "Mechanical properties (elastic modulus, tensile strength, elongation at break)",
        "Nanoparticle dispersion (TEM/SEM)"
    ],
    "main_findings": "A biodegradable shape memory PLLA nanocomposite containing surface-modified Fe3O4 nanoparticles was prepared and showed improved mechanical properties and shape memory properties versus PLLA. Shape recovery driven by an alternating magnetic field was observed, but the recovery ratio and speed under the alternating magnetic field were lower than in 70\u0000C water; this was attributed to low frequency/strength of the magnetic field producing limited heating.",
    "effect_direction": "benefit",
    "limitations": [
        "No magnetic field parameters (frequency/field strength) are provided in the abstract.",
        "No quantitative results are provided in the abstract for mechanical or shape recovery outcomes.",
        "No sample size or number of specimens is reported in the abstract."
    ],
    "evidence_strength": "insufficient",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "shape memory polymer",
        "PLLA",
        "Fe3O4 nanoparticles",
        "alternating magnetic field",
        "magnetothermal actuation",
        "biodegradable nanocomposite",
        "mechanical properties"
    ],
    "suggested_hubs": []
}

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