What absorbs at 828 cm⁻¹ in an FTIR spectrum?
A band near 828 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
A band near 828 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Phosphate (PO4) | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Ring structure | 2 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Imide | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| PVA | 828, 1660, 2930 | Alkyl C-H | 3 |
| PVP | 828, 2983, 1648 | Alkyl C-H | 1 |
| Epoxy | 828, 1660, 1735 | Alkyl C-H, Aromatic ring | 1 |
| polyurethane | 828, 2270, 1700 | Alkyl C-H | 1 |
| epoxy resin | 828, 905, 1100 | Alkyl C-H, Aromatic ring | 1 |
| alginate | 828, 1100, 1715 | Alkyl C-H | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 828 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Literature behind these assignments
-
Aromatic ring confidence 1.0
“The sharp and intense band at cm-1 828 could be ascribed to out of plane vibrations of the p-disubstituted benzene ring [41, 44, 45].”
Synthesis, crystal structures, quantum chemical studies and corrosion inhibition potentials of 4-(((4-ethylphenyl)imino)methyl)phenol and (E)-4-((naphthalen-2-ylimino) methyl) phenol Schiff bases DOI: 10.1016/j.molstruc.2017.06.104 -
Water (H2O) confidence 1.0
“absorption losses at 1646 and below There The presence of adsorbed water must therefore play an are also three distinct absorption gain peaks at 828, 745, and important role in the activity of the modes giving rise to the cm-1 685 superimpo”
Influence of Adsorbed Water on Phonon and UV-Induced IR Absorptions of TiO<sub>2</sub> Photocatalytic Particle Films DOI: 10.1021/jp0471812 -
C c single bond confidence 1.0
“The detected peaks at 828 cm-1 steady value for the remaining part of the investigated waveand 888 are assigned to C-C chain in the polymer length.”
Improvement of Optical Properties of Functionalized Polyvinyl Alcohol-Zinc Oxide Hybrid Nanocomposites for Wide UV Optoelectronic Applications DOI: 10.1007/s10904-023-02616-w -
Borate confidence 1.0
“The band cm-1 at 828 quently the removal efficiency of the six cleaning sysis assigned to the B-O stretching vibration”
Evaluation of polyvinyl alcohol–borax/agarose (PVA–B/AG) blend hydrogels for removal of deteriorated consolidants from ancient Egyptian wall paintings DOI: 10.1186/s40494-019-0264-z -
Aromatic ring confidence 1.0
“Moreover, the characteristic absorption bands of the benzene ring near 1509 cm-1 (Stretching vibration of -C = Cskeleton in the benzene ring) and 828 cm-1 (in-plane deformation”
Reinforced Structure Effect on Thermo-Oxidative Stability of Polymer-Matrix Composites: 2-D Plain Woven Composites and 2.5-D Angle-Interlock Woven Composites DOI: 10.3390/polym14173454 -
Alkyl C-H confidence 1.0
“3 respectively attributed to the asymmetric stretching of C-O-C and the deformation of C=CH [43,44], 2 cm-1 while the peak at 828 might be assigned to CH rocking [43].”
Hosseini 等 - 2017 - Polymethacrylate Coated Electrospun PHB Fibers as DOI: 10.3390/s17102292 -
Imide confidence 1.0
“cm-1 At lower wavenumbers, the sharp band between 828 and 800 is assigned to the out-of-plane bending of the H-C= vibration present in maleimide (MI) units and 1-4 subcm-1 stituted aromatic rings.”
Influence of the Epoxy Resin Process Parameters on the Mechanical Properties of Produced Bidirectional [45] Carbon/Epoxy Woven Composites DOI: 10.3390/polym -
Alkyl C-H confidence 1.0
“The bands at 1418 cm-1 and 828 cm-1 are related to the scissor vibration of δCH2 and stretching of the zigzag-shaped carbon base of νC-C, respectively.”
Composite Cement Materials Based on -Tricalcium Phosphate, Calcium Sulfate, and a Mixture of Polyvinyl Alcohol and Polyvinylpyrrolidone Intended for Osteanagenesis DOI: 10.3390/polym15010210
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