Hair Resilience: Advanced Techniques to Evaluate Hair Bonding and Validate Cosmetic Claims
- TRI Princeton
- Jan 16
- 2 min read
This third TRI Talk of 2025/26 was given by Dr. Larry Senak, and outlined the evaluation of hair bond repair using vibrational spectroscopy (which includes IR and Raman). As ever, the event stimulated significant discussion and pushed the boundaries of what we know – particularly relating to the potential recovery of hair from bleach damage through the re-formation of disulfide bonds, which can now be monitored and quantified.
After a brief introduction to the molecular structure of the hair fiber, including how the adjacent peptide chains with hair structure interact with each other, Larry gave an overview of vibrational spectroscopic techniques, including when to use IR or Raman to probe samples and a discussion of the advantages and disadvantages of each, with examples. The impact of bleaching on the hair fiber’s hydrogen bonding network, and how we can monitor it – both in terms of structure damage and repair – was then covered, alongside an overview of how disulfide bonds can be broken (focussing on chemical damage), and how confocal Raman spectroscopy can quantify bleaching damage and repair across the hair fiber. The final section of the talk included a discussion around the observation that disulfide bonds broken during chemical treatments appear to naturally repair in some hair fibers, how the use of these spectroscopies can support bond repair claims for products, and some thoughts for the further development of this work in future.
If you missed the talk and would like to watch it again, head to your original Zoom link and it should be available on playback. These talks are also available in the TRI library and are free to access for TRI Member Companies. The TRI Talks from 2025 are also available to purchase as a Box Set for USD 25.
If you would like more information about becoming an TRI Member Company and all the advantages that this offers, please get in touch!
The next TRI Talk is by Dr Ernesta Malinauskyte on 28th January, and is titled “Scratching the Surface: Lipids, Protection & the Sebum–Microbiome Relationship”.