Electric Field Controlled Self-Assembly of Hierarchically Ordered Membranes.

Advanced functional materials · 2012 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 3191

Study snapshot

PublicationAdvanced functional materials · 2012

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

Self-assembly in the presence of external forces is an adaptive, directed organization of molecular components under nonequilibrium conditions. While forces may be generated as a result of spontaneous interactions among components of a system, intervention with external forces can significantly alter the final outcome of self-assembly. Superimposing these intrinsic and extrinsic forces provides greater degrees of freedom to control the structure and function of self-assembling materials. In this work we investigate the role of electric fields during the dynamic self-assembly of a negatively charged polyelectrolyte and a positively charged peptide amphiphile in water leading to the formation of an ordered membrane. In the absence of electric fields, contact between the two solutions of oppositely charged molecules triggers the growth of closed membranes with vertically oriented fibrils that encapsulate the polyelectrolyte solution. This process of self-assembly is intrinsically driven by excess osmotic pressure of counterions, and the electric field is found to modify the kinetics of membrane formation, and also its morphology and properties. Depending on the strength and orientation of the field we observe a significant increase or decrease of up to nearly 100% in membrane thickness, as well as the controlled rotation of nanofiber growth direction by 90 degrees, resulting in a significant increase in mechanical stiffness. These results suggest the possibility of using electric fields to control structure in self-assembly processes involving diffusion of oppositely charged molecules.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In an aqueous in vitro self-assembly system (negatively charged polyelectrolyte with positively charged peptide amphiphile), an applied electric field modified the kinetics of membrane formation and altered membrane morphology and properties. Field strength and orientation were associated with increases or decreases in membrane thickness (reported up to nearly 100%), a 90° rotation of nanofiber growth direction, and increased mechanical stiffness.

Outcomes measured

membrane formation kinetics
membrane thickness
nanofiber growth direction/orientation
membrane morphology
mechanical stiffness

Limitations

No electric field parameters (e.g., field strength values, waveform/frequency, exposure duration) are provided in the abstract.
No sample size or replication details are provided in the abstract.
In vitro materials self-assembly study; not a health or epidemiology outcome.

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": null,
    "source": "external electric field",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "membrane formation kinetics",
    "membrane thickness",
    "nanofiber growth direction/orientation",
    "membrane morphology",
    "mechanical stiffness"
  ],
  "main_findings": "In an aqueous in vitro self-assembly system (negatively charged polyelectrolyte with positively charged peptide amphiphile), an applied electric field modified the kinetics of membrane formation and altered membrane morphology and properties. Field strength and orientation were associated with increases or decreases in membrane thickness (reported up to nearly 100%), a 90° rotation of nanofiber growth direction, and increased mechanical stiffness.",
  "effect_direction": "mixed",
  "limitations": [
    "No electric field parameters (e.g., field strength values, waveform/frequency, exposure duration) are provided in the abstract.",
    "No sample size or replication details are provided in the abstract.",
    "In vitro materials self-assembly study; not a health or epidemiology outcome."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "electric field",
    "self-assembly",
    "polyelectrolyte",
    "peptide amphiphile",
    "membrane",
    "nanofibers",
    "morphology",
    "mechanical stiffness",
    "kinetics"
  ],
  "suggested_hubs": [
    {
      "slug": "engineering",
      "weight": 0.9,
      "reason": "Study investigates how applied electric fields control material self-assembly and membrane properties."
    }
  ]
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1002/adfm.201101538
PubMed: 23166533

Read the original paper →

Related papers

← Back to the Research Library