@article{williams_vacchi_santos_szymczyk_umbuzeiro_freeman_2022, title={Evaluation of the Toxicological and Color Properties of Anionic Hydrophobic Monoazo Dyes for Sustainable Human Hair Coloration}, volume={10}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.1c05702}, DOI={10.1021/acssuschemeng.1c05702}, abstractNote={The design of hair dyes having environmentally benign characteristics in addition to very good durability to washing and UV light is of importance to overcome the limitations of conventional permanent hair dyes in the marketplace. As a step toward meeting this vision, we synthesized anionic azo dyes having a built-in C4, C8, or C12 alkyl chain and evaluated their hair dyeing and toxicological properties. As anticipated, the dyes increased in hydrophobicity (SlogP) with the increase in alkyl chain length. Based on prior technology, it is known that certain anionic textile dyes possessing a C12 group exhibit high affinity for wool fibers during rigorous washing in the commercial milling process. In the present study, the dye containing the C8 chain displayed the greatest uptake and the most promise as a potential permanent hair dye. Further, dyes containing a C4 or C8 carbon chain were found to be nontoxic ≤100 mg L using the crustaceans Daphnia similis and Parhyale hawaiensis as test organisms. The dye containing a C12 carbon chain provided an EC50 of 57.4 mg L–1 using D. similis, but it was nontoxic ≤100 mg L–1 to P. hawaiensis. All dyes were nontoxic using the algae Raphidocelis subcapitata, and none of the dyes exhibited mutagenicity toward the strains used.}, number={8}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Williams, Tova N. and Vacchi, Francine I. and Santos, Amanda and Szymczyk, Malgorzata and Umbuzeiro, Gisela de Aragao and Freeman, Harold S.}, year={2022}, month={Feb}, pages={2593–2601} }
 @article{williams_2022, title={Mad about madder}, volume={7}, ISSN={["1755-4349"]}, url={http://dx.doi.org/10.1038/s41557-022-01015-x}, DOI={10.1038/s41557-022-01015-x}, number={8}, journal={NATURE CHEMISTRY}, publisher={Springer Science and Business Media LLC}, author={Williams, Tova N.}, year={2022}, month={Jul} }
 @article{williams_vacchi_santos_aragaumbuzeiro_freeman_2022, title={Metal-complexed monoazo dyes as sustainable permanent hair dye alternatives-Toxicological and durability properties}, volume={197}, ISSN={["1873-3743"]}, url={https://doi.org/10.1016/j.dyepig.2021.109819}, DOI={10.1016/j.dyepig.2021.109819}, abstractNote={As a new approach to permanent/oxidative hair dyes, we demonstrated that certain monoazo dyes containing substituents that enable diffusion into hair fibers and subsequent chelation/complexation using benign metal ions (Al3+ and Fe3+), rather than a harsh oxidant and strong alkali, merit consideration in this application area. This is important, because billions of individuals worldwide color their hair using permanent hair dye products that can contain aromatic amines and phenols that display genotoxicity and/or skin sensitization (e.g., para-phenylenediamine, PPD). Herein, our work is extended to an examination of the toxicological properties and durability of metallizable monoazo dyes, in comparison to a commercially used permanent hair dye product. Results from the Salmonella/microsome mutagenicity assay and from acute toxicity tests using aquatic test organisms (Daphnia similis, 48-h and Parhyale hawaiensis, 96-h) indicated that the proposed dyes were significantly less toxic than the top-eight permanent hair dye precursors utilized annually. Regarding durability, monoazo dye chelation in situ led to a higher degree of resistance to removal by washing than a commercial permanent hair dye. Taken together, these results further demonstrate the potential of the dyes as sustainable alternatives to conventional permanent hair dyes.}, journal={DYES AND PIGMENTS}, publisher={Elsevier BV}, author={Williams, Tova N. and Vacchi, Francine I. and Santos, Amanda and AragaUmbuzeiro, Gisela and Freeman, Harold S.}, year={2022}, month={Jan} }
 @inbook{williams_2021, place={Berlin, Heidelberg}, title={Coloration, Hair}, ISBN={9783642278518}, DOI={10.1007/978-3-642-27851-8_441-1}, booktitle={Encyclopedia of Color Science and Technology}, publisher={Springer}, author={Williams, T.N.}, editor={Shamey, R.Editor}, year={2021}, pages={1–10} }
 @article{williams_szymczyk_freeman_2021, title={In situ Chelation of Monoazo Dyes in Human Hair Keratin Fibers Using Environmentally Benign Metal Ions}, volume={4}, url={https://doi.org/10.1021/acsabm.1c00512}, DOI={10.1021/acsabm.1c00512}, abstractNote={The coloration of human hair keratin fibers has long involved the oxidative coupling of primarily aromatic amines and phenols inside the fibers with the aid of harsh agents such as H2O2 and NH4OH. Further, the traditional process has exposed millions of consumers and their hairstylists to toxic substances such as skin sensitizers. While alternative hair dyeing processes have been explored, they fail to be competitive with the traditional method, for reasons including impracticality and limited colors achievable. In the present study, we developed an approach to imparting color to human hair fibers that involves entrapping colorants inside hair fibers by forming chelated monoazo dyes in situ. Dyes employed were based on monoarylide, arylazopyrazolone, and arylazonaphthol families, which display yellow, orange, and magenta colors on dyed hair. The dyes were applied at 40 °C without the use of oxidants and alkali associated with current commercial hair dyes, with the best dye uptake observed when the arylazonaphthol dye was employed. The dyed hair fibers showed good durability to washing, and treatment of these fibers with Al3+ or Fe3+ ions at 40 °C led to the rapid in situ formation of 1:2 metal/dye structures. In addition, the dyed hair was soft, indicating that chelated dye occupies the interior of the fibers rather than the surface. Such an approach can be applied to the coloration of other materials, including textiles.}, number={8}, journal={ACS Applied Bio Materials}, publisher={American Chemical Society (ACS)}, author={Williams, Tova N. and Szymczyk, Malgorzata and Freeman, Harold S.}, year={2021}, month={Aug}, pages={6195–6202} }
 @inbook{williams_2021, place={Berlin, Heidelberg}, title={Melanin}, DOI={10.1007/978-3-642-27851-8_446-1}, booktitle={Encyclopedia of Color Science and Technology}, publisher={Springer}, author={Williams, T.N.}, editor={Shamey, R.Editor}, year={2021}, pages={1–5} }
 @article{williams_freeman_2019, title={Analysis of keratin films as screening tools for predicting the efficacy of potential hair dyes}, volume={135}, ISSN={["1478-4408"]}, url={https://doi.org/10.1111/cote.12408}, DOI={10.1111/cote.12408}, abstractNote={Abstract The technology for generating high quality keratin films has recently advanced and led to their implementation in a variety of applications. As an initial step toward investigating the films as a screening tool for predicting the efficacy of potential hair dyes, CI Acid Orange 7 was applied to a set of opaque and translucent films. Overlaid time‐of‐flight secondary ion mass spectrometry images arising from protein and dye fragments revealed that dye uniformly penetrated both film types. Results also showed that the relative concentration of dye in each film complemented outcomes from ultraviolet‐visible analysis and revealed that the translucent film contained a higher dye concentration. Scanning electron microscopy analysis of film morphology suggested that the observed difference was due to the higher porosity of the opaque film, which facilitated dye desorption during the rinsing step. Consequently, the translucent film was judged to be a better substrate for screening potential new hair dyes.}, number={4}, journal={COLORATION TECHNOLOGY}, publisher={Wiley}, author={Williams, Tova N. and Freeman, Harold S.}, year={2019}, month={Aug}, pages={253–266} }
 @inproceedings{williams_van den driessche_fourches_freeman_2019, title={Designing the next generation of hair dyes using cheminformatics}, booktitle={American Chemical Society National Meeting & Expo}, author={Williams, T.N. and Van Den Driessche, G.A. and Fourches, D. and Freeman, H.S.}, year={2019}, month={Apr} }
 @inproceedings{woods_williams_ormond_2019, title={Development of a Colorimetric Sensor for the Detection of Methyl Salicylate during Man-In-Simulant Test}, booktitle={133rd NC Local Section Meeting of the American Chemical Society}, author={Woods, E. and Williams, T.N. and Ormond, R.B.}, year={2019}, month={Nov} }
 @misc{williams_van den driessche_fourches_freeman_2018, title={Chemistry to Dye For: Hair Dyes— Designing the next generation of hair dyes using cheminformatics}, author={Williams, T.N. and Van Den Driessche, G.A. and Fourches, D. and Freeman, H.S.}, year={2018}, month={Nov} }
 @article{williams_kuenemann_driessche_williams_fourches_freeman_2018, title={Toward the Rational Design of Sustainable Hair Dyes Using Cheminformatics Approaches: Step 1. Database Development and Analysis}, volume={6}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.7b03795}, DOI={10.1021/acssuschemeng.7b03795}, abstractNote={Herein, we report on the initial step of the design process of new hair dyes with the desired properties. The first step is dedicated to the development of the largest, publicly available database of hair dye substances (containing temporary and semipermanent hair dyes as well as permanent hair dye precursors) used in commercial hair dye formulations. The database was utilized to perform a cheminformatics study assessing the computed physicochemical properties of the different hair dye substances, especially within each cluster of structurally similar dyes. The various substances could be differentiated based on their average molecular weight, hydrophobicity, topological polar surface area, and number of hydrogen bond acceptors, with some overlap also observed. In particular, we found that dyes such as C.I. Basic Orange 1 and 2 were clustered among the precursors, suggesting that their diffusion behavior is similar to that of permanent hair dye precursors. We anticipate taking advantage of this interestin...}, number={2}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, publisher={American Chemical Society (ACS)}, author={Williams, Tova N. and Kuenemann, Melaine A. and Driessche, George A. and Williams, Antony J. and Fourches, Denis and Freeman, Harold S.}, year={2018}, month={Feb}, pages={2344–2352} }
 @article{williams_driessche_valery_fourches_freeman_2018, title={Toward the Rational Design of Sustainable Hair Dyes Using Cheminformatics Approaches: Step 2. Identification of Hair Dye Substance Database Analogs in the Max Weaver Dye Library}, volume={6}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.8b02882}, DOI={10.1021/acssuschemeng.8b02882}, abstractNote={We report on part 2 of the cheminformatics-assisted development of sustainable hair dyes with enhanced technical and toxicological properties. In this study, an initial similarity search analysis was performed using two reference probes (C.I. Basic Orange 1 and Orange 2) as structural templates for the identification of potential analogs among the Max Weaver Dye Library (MWDL). The analysis revealed an interesting subset of 158 MWDL compounds that were close analogs of the classical aminoazobenzene dyes. A more detailed similarity search analysis of this subset ultimately led to the selection of four dyes for further in silico quantum calculations and experimental dye uptake (color depth on hair) studies. Results from quantum calculations indicated that the ESP surface properties of these dyes were consistent with nonionic interactions between dye and keratin. Among the four dye analogs, 2-amino-6-methyl-5-(phenyldiazenyl)pyrimidin-4-ol and 2-amino-4-chloro-1,6-dimethyl-5-(phenyldiazenyl)-pyrimidin-1-ium ...}, number={11}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, publisher={American Chemical Society (ACS)}, author={Williams, Tova N. and Driessche, George A. and Valery, Alain R. B. and Fourches, Denis and Freeman, Harold S.}, year={2018}, month={Nov}, pages={14248–14256} }