RF Safe

Study of microwave non-thermal effects on hydrogen bonding in water by Raman spectroscopy

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy · 2022 · Harm · Low evidence

← Research stream
HarmLow evidencePaper 701

By comparing Raman spectra of pure water heated by oil bath versus microwave, the authors report evidence consistent with a microwave non-thermal effect. They report microwave heating causes more severe and faster disruption of fully hydrogen-bonded water str…

Study snapshot

PublicationSpectrochimica acta. Part A, Molecular and biomolecular spectroscopy · 2022
Study typein_vitro
Reported directionHarm
Evidence ratingLow

Abstract

Study of microwave non-thermal effects on hydrogen bonding in water by Raman spectroscopy Han G, Liu F, Zhang T, Xu W, Zhang Y, Wu N, Ouyang S. Study of microwave non-thermal effects on hydrogen bonding in water by Raman spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc. 2022 Sep 22;285:121877. doi: 10.1016/j.saa.2022.121877. Abstract Microwave chemistry plays an important role in organic synthesis. It has been debatable whether or not there are microwave non-thermal effects. Through analyzing the Raman spectra of pure water under two different heating methods (oil bath and microwave), the existence of microwave non-thermal effect is verified in this paper. The findings demonstrate that temperature has a significant impact on the Raman shift of the OH stretching band, which shifts to a high wave number as temperature rises and deforms the hydrogen bond (HB) network structure. Because microwave electric fields selectively heat water molecules (polar molecules) and destroy hydrogen bond structures in water, results in microwave heating more severe destruction of fully hydrogen-bonded structure than oil bath and transforms it more quickly into the partially hydrogen-bonded and free H2O structure. Under the non-thermal effects of microwaves, hydrogen bonds that initially existed as stable tetrahedral structures are transformed into chain-like structures more rapidly. By comparing the Raman shift, it can be found that the microwave non-thermal effect can affect the hydrogen bonding in water for a long time (>1h). This study provides an experimental basis for enriching the mechanism of microwave non-thermal effects on hydrogen bonding. pubmed.ncbi.nlm.nih.gov

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 directionharm
PopulationNot supplied
Sample sizeNot supplied
Exposuremicrowave · >1h
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

By comparing Raman spectra of pure water heated by oil bath versus microwave, the authors report evidence consistent with a microwave non-thermal effect. They report microwave heating causes more severe and faster disruption of fully hydrogen-bonded water structures than oil-bath heating, with effects on hydrogen bonding reported to persist for >1 hour.

Outcomes measured

  • Raman shift of OH stretching band in water
  • Hydrogen bond (HB) network structure changes in water (fully hydrogen-bonded vs partially hydrogen-bonded/free H2O; tetrahedral vs chain-like structures)
  • Persistence of microwave non-thermal effects on hydrogen bonding (>1h)

Limitations

  • No microwave exposure parameters reported (e.g., frequency, power, field strength, SAR).
  • In vitro/physical chemistry study in pure water; no biological or health outcomes assessed.
  • Sample size and experimental replication details not provided in the abstract.
View raw extracted JSON
{
  "study_type": "in_vitro",
  "exposure": {
    "band": "microwave",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": ">1h"
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Raman shift of OH stretching band in water",
    "Hydrogen bond (HB) network structure changes in water (fully hydrogen-bonded vs partially hydrogen-bonded/free H2O; tetrahedral vs chain-like structures)",
    "Persistence of microwave non-thermal effects on hydrogen bonding (>1h)"
  ],
  "main_findings": "By comparing Raman spectra of pure water heated by oil bath versus microwave, the authors report evidence consistent with a microwave non-thermal effect. They report microwave heating causes more severe and faster disruption of fully hydrogen-bonded water structures than oil-bath heating, with effects on hydrogen bonding reported to persist for >1 hour.",
  "effect_direction": "harm",
  "limitations": [
    "No microwave exposure parameters reported (e.g., frequency, power, field strength, SAR).",
    "In vitro/physical chemistry study in pure water; no biological or health outcomes assessed.",
    "Sample size and experimental replication details not provided in the abstract."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "microwave",
    "non-thermal effects",
    "Raman spectroscopy",
    "water",
    "hydrogen bonding",
    "OH stretching band",
    "heating methods",
    "oil bath"
  ],
  "suggested_hubs": []
}
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: 10.1016/j.saa.2022.121877
PubMed: 36174402

Read the original paper →

Related papers

← Back to the Research Library