Going with the flow

Seher Özkan uses rheology to take guesswork out of consumer perceptions [tweet this]

Seher Özkan has followed her curiosity from Turkey to the United States and from mechanical engineering to rheology (the physics of how matter flows). A career that started with internships in foundries – drawing questions from workers about what a woman was doing there – has transformed into playing a key role in the development of skin care products, pharmaceuticals and paint.

It has been an almost magical transformation – perhaps with good reason.

“I was born in Midas City, the King Midas of the golden touch,” she says. “The village has ruins from ancient Christianity, Phrygians and some other really ancient civilizations. I used to play in those ruins. Being in that type of village kind of makes you ask a lot of questions.”

Now she’s answering tricky questions about how flow properties may affect consumers’  perceptions, primarily for skin-care products, as a senior scientist with the Materials Science team at the Ashland Specialty Ingredients lab in Bridgewater, N.J.

“Performance is important, but performance is secondary,” she says. “When you are first buying a product, you don’t know about the performance. What makes you buy the product is your initial perception. The second time you’re buying it’s about the performance.”

Making the subjective measurable
But how do you translate something as subjective as perception – which, Özkan points out, includes psychological factors – into measurable information that scientists can work with?

“Basically, it was a fingerprinting of the formulations. Just like people have fingerprints, we can generate ‘fingerprints’ for every formulation that are unique to materials used,” she explains. “It made it easier for formulators to see the differences. Then we applied some sophisticated mathematical analysis on that data, so we have more knowledge to correlate with the sensory perception.”

In short, Özkan’s work has taken the guesswork out of the process and created data-driven product evaluations, says Roger McMullen, senior scientist in Materials Science.

“Seher has found ways to take perception from being a subjective measurement and make it into an objective measurement that we can actually engineer, and predict outcomes for new products,” he says.

Driving precision
“It really lets you precisely identify the end point where you want to be with your product. You can say that we have certain A, B and C properties and we want this formulation or this new product to deliver those properties,” McMullen adds. “With the techniques she’s utilizing, you can arrive at those points with much greater precision.”

The key is determining which ingredients in a product drive the perceptions.

“We focused on how to objectively measure and link those physical aspects to the chemical structure,” Özkan says. “Then you can go back, change your chemical structure and modify that perception.”

That capability can be crucial, especially for companies selling expensive cosmetics and other skin-care products.

“It’s very important, especially for a skin cream. Even if you are certain that the product will work, if it feels sticky or nasty on your skin, you’re not going to want to wear it,” Özkan says. “You’re not going to spend $500 on that product if there is another that feels nicer.

“Using simplified measurement techniques may not be enough. So you need as much information as possible to see which one actually defines what customers are trying to tell us,” she adds. 

Her expertise in rheology has helped customers in fields typically perceived as unrelated. 

Very broad industrial applications
“It is relevant to many industries now – personal care, coatings, pharmaceuticals, agriculture,” she points out. “In one way or another, everything flows. We get to work with a variety of customers and you learn from each and you may use that knowledge for other customers.”

Road-tripping with her sister, Serpil, at right, and a friend on the left

If you think of cosmetics for buildings, the big new thing in paint is one-coat coverage. 

“We use the profilometer to analyze paint, to study the hiding properties. Customers, people like us, want it to cover without the necessity of a second coat,” she says. “That requires a more sophisticated material design. If you don’t have the right measurement tools, you don’t know what you’re dealing with and you don’t know what you should be targeting to fix.”

While they didn’t actually watch paint dry, that’s where Özkan and her colleagues found the solution. Some areas were drying too thick and others too thin.

“You prefer to have a uniform thickness so it will color everything,” she says. “You need to be able to measure that topography. Our approach was using a profilometer that was used for a pharmaceutical application for other purposes.

Innovation in lab applications
“We knew it existed, we knew what it was used for, so we applied that technique to measuring the correct thickness of paint films. Now you can go back and fix what is causing thick and thin sections,” she says.

Approaching problems from a rheological perspective sheds new light on problems, says Larry Senak, a principal scientist in Ashland’s Measurement Science group.

“Seher‘s vantage points are often fresh and different. Because Seher comes from an engineering background, she’s able to apply certain disciplines to understanding our problems in a way that somebody that comes from a pure chemistry background would not,” he says. “So we get a chance to watch these two worlds come together and mesh. In the end, we get a better product to our customers; a perceptibly better product.”

Achieving that goal delivers satisfaction to Ashland’s scientists.

“You get a high by simply talking about a new problem, discovering something new about it. We see delight in each other’s eyes,” says Özkan. “Innovation can be just applying an existing method from another field to your problem. It could be that simple. Or analyzing data that already was there through a different pair of eyes and coming up with a different conclusion.

“I like working with my team,” she adds. “They’re like my family here. They’re really good scientists; they share the same passion that I do; we work well together. Learning new things makes me fulfilled.”

Meet Seher Özkan

When she was in elementary school, Seher Özkan would listen to a radio show about scientists. It led an already-inquisitive child – who turned out to be math star – to a career. Marie Curie and Thomas Edison were inspirations.

“I remember Marie Curie’s life story. I thought, ‘Wow. She made a big difference and she’s a woman.’ I wanted to be like her,” Özkan recalls. “Thomas Edison’s patience stuck in my mind. If you want success you have to be patient, you have to keep trying.”

Sharing a quiet moment with her mother, Firdevs

Encouraged by her father, a strict, rules-bound school principal, and her mother, a homemaker, she went to Istanbul Technical University to study mechanical engineering.

Seher's father, Huseyin, at Ayasofya in Istanbul

“In some classes, I was the only woman among 80 guys,” she recalls. “In my first internship, in a huge casting factory, I got questions from the workers: ‘Why aren’t you a nurse? Why aren’t you a teacher? What are you doing here?’ I like being different and that is good.”

First Thanksgiving dinner with her friends

After coming to the U.S., where her sister was already working as a respiratory therapist, Özkan began working as a research assistant at Stevens Institute of Technology in Hoboken, N.J. An interest in tissue engineering led to her transition into rheology. After earning her doctorate, she joined Ashland in March 2009.

A self-described nerd, she enjoys spending free time doing photography (“I had to videotape experiments in grad school”) and reading classic literature (she has read “War and Peace” three times. But she adds, “I like talking the most.”



  • Ph.D., chemical engineering, Stevens Institute of Technology (SIT).
  • Master’s of engineering, chemical engineering, SIT.
  • Master’s of engineering, mechanical engineering, Istanbul Technical University (ITU)
  • Bachelor of Science, mechanical engineering, ITU
  • Graduate certificate, enterprise project management, SIT.

With Dr. D.M. Kalyon, her advisor, at graduation

Publications (sample)

  • “Functionally graded polymeric graft substitutes and scaffolds for tissue engineering can be fabricated via various extrusion methods,” with D. Kalyon, C. Erisken, A. Ergun-Butros, X. Yu, H. Wang, A. Valdevit and A. Ritter, Tissue Science & Engineering, 2014.
  • “Shell-core bi-layered scaffolds for engineering of vascularized osteon-like structures,” with X. Chen, A. Ergun, H. Gevgilili, D. Kalyon and H. Wang,  Biomaterials, 2013.
  • “Synthesis and reactive features of a terpolymer: poly(N-vinyl-2-pyrrolidone-co-vinyl acetate-co-glycidyl methacrylate),” with D. Hood, D. Kranbuehl, A. Glover, L. Senak, C. Zhu and O. Musa, Journal of  Applied Polymer Scıence, 2012.
  • “Characterization of yield stress and slip behavior of skin/hair care gels using steady flow and LAOS measurements and their correlation with sensorial attributes,” with T. Gillece, L. Senak and D. Moore, International Journal of Cosmetic Science, 2012.
  •  “Functionally graded β-TCP/PCL nanocomposite scaffolds for bone tissue engineering: In vitro evaluation with human fetal osteoblast cells,” with D. Kalyon and X. Yu, Journal of Biomedical Matter Research, 2010.


  • Society of Cosmetic Chemists
  • American Institute of Chemical Engineers
  • Materials Research Society
  • Society of Rheology
  • American Chemical Society


  • Outstanding Achievement in Pursuing Ph.D. in Chemical Engineering, from Exxon Mobil, 2009.
  • Fellowship in Chemistry, Pharmaceutical Science, Material Science and Engineering, from Merck Research Laboratories, 2008.