Warner first articulated the concept of Non-Covalent
Derivatization (NCD) at a conference in 1997, but he employed this concept in practice as early as 1988. He initially devised this method as a solution to a common engineering problem that
hydroquinone (HQ), an essential developer in
Polaroid instant photography, is not readily
soluble in water. HQ is desired in more modern applications for its potency as a
reducing agent, and until Warner, this problem was typically addressed by traditional chemical synthesis, or modifying a target material by attaching various
functional groups via
covalent bonds, also referred to as "covalent derivatization."
Inspired by phenomena he observed in nature, Warner proposed NCD as an alternative means of modifying a target material, not via covalent bonds, but innate
intermolecular forces. The applications of this process ranged from
film development to more recently
cosmetic dermatology. NCD is now most often employed as an effective means of reducing the
environmental impact of a process, by the minimizing the materials and energy required and
waste produced, and is successfully applied in the production of
pharmaceuticals as well as
fragrances,
agrochemicals,
pigments, and
food additives. Warner holds patents based on NCD in many of these areas, most notably drugs to treat
nervous system disorders, additives to increase
recyclability of asphalt, and processes to reverse
depigmentation in hair. NCD was also the impetus for a consequential meeting between Warner and the
Environmental Protection Agency (EPA), after the agency rejected a manufacturing model proposed by Polaroid based on the method. It was there that Warner was reunited with his long-time friend
Paul Anastas, and the two began to formulate the
Twelve Principles of Green Chemistry. Warner became so infatuated with Non-Covalent Derivatization that his
Massachusetts license plate bears the initials NCD. == Green Chemistry: Theory and Practice ==