# Versatile photoactive latex particles for singlet oxygen production as a tool for sustainable solutions

Guillaume Mageste, M. Ali Aboudzadeh, Charlène Boussiron, Luca Petrizza, Sylvie Lacombe-Lhoste, Thierry Pigot, Mickael Le Béchec, Maud Save

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Guillaume Mageste, M. Ali Aboudzadeh, Charlène Boussiron, Luca Petrizza, Sylvie Lacombe-Lhoste, et al.. Versatile photoactive latex particles for singlet oxygen production as a tool for sustainable solutions. Club Emulsion, Oct 2025, Pau, France. hal-05404181

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Submitted on 8 Dec 2025

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Distributed under a Creative Commons Attribution 4.0 International License
# Versatile photoactive latex particles for singlet oxygen production as a tool for sustainable solutions

Guillaume Mageste, Ali Aboudzadeh, Charlène Boussiron, Luca Petrizza, Sylvie Lacombe, Thierry Pigot, Mickaël Le Bechec, Maud Save

IPREM UMR 5254, CNRS UPPA, 2 av. Président Pierre Angot, 64053 Pau, France

Contact : guillaume.mageste@univ-pau.fr

## Interest of the study

Rose Bengal covalent grafting on polymer colloids for singlet oxygen production

## Applications

### Oxygenation of biobased molecules
Flow photochemistry

### 2 generations of ethanolic dispersions of Rose-Bengal polymer particles

Collaboration
R. Radjagobalou,
A. Desriac, J-F.
Blanco, K.
Loubière

<figure><img src="image_2.png" /></figure>

LABORATOIRE
DE GÉNIE
CHIMIQUE

TOULOUSE • UMR 5503

Conversion of alpha-terpinene versus time for free RB and microgel-VBRB [2]
Led panel, 38 mW.cm⁻² 400-800 nm

<figure><img src="image_3.png" /></figure>

* ✓ 100% conversion α-terpinene into ascaridole / Reactivity RB particles ~ free RB

* ✓ Very short residence times (< 6 min)

* ✓ Low photobleaching (RB- colloids <1- 5 %)

* ✓ High Selectivity to produce ascaridol

* ✓ Similar efficiency for all latex particles Dh / DP block core-shell copolymer particles

<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /></figure>

α- Terpinene

Ascaridole

<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /></figure>

Latent colloids

<figure><img src="image_9.png" /></figure>

Photoactive microgels

✓ OFF/ON photosensitized production of ¹O₂ with Poly(N-vinylcaprolactam) microgels [1]

<figure><img src="image_10.png" /></figure>

Poly(oligo(ethylene glycol) methyl ether methacrylate)
Poly(benzyl methacrylate)

<figure><img src="image_11.png" /></figure>

Photoactive latexes

<figure><img src="image_12.png" /></figure>

Time-evolving photobleaching for free RB and latexes EMARB by UV-vis spectroscopy

<figure><img src="image_13.png" /></figure>

300 W Xe lamp, 25 mW.cm⁻²
400-800 nm to enhance
photobleaching to assess Free vs
grafted properties

<figure><img src="image_14.png" /></figure>

✓ Latexes are less sensitive to photobleaching than free RB

Conversion of alpha-terpinene versus time for free RB and latexes EMARB

Led panel, 38 mW.cm⁻² 400-800 nm

<figure><img src="image_15.png" /></figure>

### Antibacterial Photoactive coating
Film forming latex

### Mechanical properties

<figure><img src="image_16.png" /></figure>

ESPCI

<figure><img src="image_17.png" /></figure>

PARIS

Collaboration Helen Minsky, Constantino Creton (ESPCI), Virginie Pellerin (IPREM, AFM)

AFM picture of RB based latex films

<figure><img src="image_18.png" /></figure>

Deformation

<figure><img src="image_19.png" /></figure>

<figure><img src="image_20.png" /></figure>

* ✓ Tunable mechanical properties according to PAA fraction

* ✓ Similar trend in the presence of photosensitizer in the shell

<figure><img src="image_21.png" /></figure>

Surfactant-free core-shell
photoactive latexes [3] [4]

Aqueous
solution of Escherichia Coli
Gram negative bacteria in
Tryptic soy broth/PBS

Casted annealed P(AA-
co-EARB₀.₁%)₇₀-b-
PnBA₇₀₀ latex

<figure><img src="image_22.png" /></figure>

Cell culture well plate
24 well, material: PS

### Antibacterial activity against E.Coli

<figure><img src="image_23.png" /></figure>

Collaboration P. Fernandez S. McMichael

Ulster
University

<figure><img src="image_24.png" /></figure>

White led panel (5 mW.cm⁻²)

<figure><img src="image_25.png" /></figure>

Coating prepared by simple casting of film-forming polyacrylic waterborne latex

* ✓ Low level of leaching

* ✓ Low contact toxicity

* ✓ Inactivation of E. Coli bacteria under white light in 4 hours: efficient antibacterial coating

## Green Chemistry

## Conclusion

<figure><img src="image_26.png" /></figure>

### Waste prevention

Recycle photosensitizer
Supported on polymer colloids
Separation procedures

<figure><img src="image_27.png" /></figure>

<figure><img src="image_28.png" /></figure>

<figure><img src="image_29.png" /></figure>

### Atom economy

Photon
Reduced steps hv

<figure><img src="image_30.png" /></figure>

### Hazard reduction

O₂ from air as reactant
Low energy LED sources / visible light

<figure><img src="image_31.png" /></figure>

<figure><img src="image_32.png" /></figure>

<figure><img src="image_33.png" /></figure>

### Energy efficiency

Room T° photochemistry
Process intensification Flow
photochemistry

Good level of photostability

<figure><img src="image_34.png" /></figure>

<figure><img src="image_35.png" /></figure>

<figure><img src="image_36.png" /></figure>

### Safer solvents

Polymerization in dispersed media
Eco-friendly solvent (EtOH, H₂O)

<figure><img src="image_37.png" /></figure>

### Renewable feedstocks

Carbon footprint
Biobased feedstock
photo-oxidized

<figure><img src="image_38.png" /></figure>

* Syntheses of **photoactive** Rose Bengal based polymer particles

* Versatile media from polymer colloids (water, ethanol)

* Versatile and promising applications (coating->surface disinfection ; flow photooxygenation)

### Acknowledgements

The research projects have received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 893426 from ANR (APOFLOW project ANR-21-CE06-0038-01 and ANR-15-CE08-0005).

### References

[1] L. Petrizza, M. Le Bechec, E. Decompte, H. El Hadri, S. Lacombe, M. Save Polymer Chemistry. **2019**, 10, 3170

[2] M. Save, K. Loubière et coll. ACS Sust. Chem. & Eng. **2020**, 8, 18568

[3] C. Boussiron, M. Le Bechec, L. Petrizza, J. Sabalot, S. Lacombe, M. Save Macromol. Rapid. Commun. **2018**, p 1800329.

[4] C. Boussiron, M. Le Bechec, J. Sabalot, S. Lacombe, M. Save Polymer Chemistry **2021**, 12, 134 - 147