Bubble boy Ram Sabnis helped an inventor complete his decade-long quest to create a new kids’ toy: the first bubbles with disappearing color, so they won’t stain your kids or your floor (see photos). Like sticky notes, their impermanence is their selling point (via Boing Boing). I knew that textile industry would come in handy someday!
Ram Sabnis is a leader among a very small group of people who can point to a dye-chemistry Ph.D. on their wall. Only a handful of universities in the world offer one, and none are in the U.S. (Sabnis got his in Bombay). He holds dozens of patents from his work in semiconductors (dying silicon) and biotechnology (dying nucleic acids)…
Sabnis told them he’d have it ready to market in a year… “This is the most difficult project I have ever worked on,” Sabnis says now… For months, he ran 60 to 100 experiments a week, filling notebooks with sketches of molecules, spending weekends in the library studying surfactant chemistry, trying one class of dyes after another…
He synthesized a dye that would bond to the surfactants in a bubble to give it bright, vivid color but would also lose its color with friction, water or exposure to air… go away completely, as though it had never been there. When one of these bubbles breaks on your hand, rub your hands together a few times and look: Poof. Magic. No more color… [Link]
Ah, lactone rings. Why didn’t I think of that 
Sabnis’s solution was to build a dye molecule from an unstable base structure called a lactone ring that functions much like a box. When the ring is open, the molecule absorbs all visible light save for one color—the color of the bubble. But add air, water or pressure, and the box closes, changing the molecule’s structure so that it lets visible light pass straight through. Sabnis builds each hue by adding different chemical groups onto this base.
“Nobody has made this chemistry before,” Sabnis says. “All these molecules—we will make 200 or 300 to cover the spectrum—they don’t exist. We have synthesized a whole new class of dyes…” [Link]
There are many other potential applications besides bubbles:
Among the ideas Kehoe has already mocked up are a finger paint that fades from every surface except a special paper, a hair dye that vanishes in a few hours, and disappearing-graffiti spray paint. There’s a toothpaste that would turn kids’ mouths a bright color until they had brushed for the requisite 30 seconds, and a soap that would do the same for hand washing.
He’s also thinking outside the toy chest, mucking around in the lab on weekends making things like a Swiffer that leaves a momentary trace showing where you’ve Swiffered and a temporary wall paint that would let you spend a few hours with a color before committing to it. [Link]
