Dr. Laurence (Larry) Senak
Dr. Laurence (Larry) Senak
Dr. Laurence (Larry) Senak is a physical chemist with a broad range of research experience and interests. This experience ranges from polymer characterization to the use of vibrational spectroscopies (Infrared and Raman) and microscopic imaging techniques towards understanding the interactions between personal care chemistries and various substrates, such as skin and hair.
Prior to obtaining his doctorate, Dr. Senak was employed by GAF corporation for 11 years. During that time, he was the first to publish the absolute molecular weight distributions of Povidone and its copolymers, as well as the bulk of the GAF polymer portfolio with size exclusion chromatography coupled to light scattering and viscometric techniques.
In 1994 Dr. Senak obtained his doctorate from Rutgers University. The focus of his thesis research was the application of Infrared spectroscopy to quantify and understand the acyl chain conformational order of lipid bilayers upon interaction with proteins and steroids (including cholesterol). This work was followed by post-doctoral studies in the physics department of the City College of New York, applying vibrational spectroscopy to the study the bond energies between Cellular Retinol Binding Protein (CRBP-I) and its retinal ligand.
In 1996 Dr. Senak returned to GAF Corporation which had become International Specialty Products (ISP), to the polymer characterization laboratory. Here, he explored and introduced such techniques as MALS (Multi Angle Light Scattering), Dynamic Light Scattering (DLS), and differential viscosity measurements to study macromolecular weight, size, and conformation in solution. Dr. Senak subsequently was promoted to Analytical Section Manager responsible for microscopy (including SEM), elemental analysis (ICP-OES etc.), wet methodologies, as well as the polymer characterization laboratory.
In 2008, Dr. Senak joined the Materials Science Department of ISP (later to become part of Ashland) as a Principal Scientist to return to vibrational spectroscopy, and employ vibrational spectroscopic micro-imaging to the studies of interactions between product chemistries and biological substrates. Dermal and hair penetration of products was spectroscopically mapped as well as the biological effect natural bioactive products upon single cells such as fibroblasts and adipocytes. This period also saw detailed studies into the modification of the skin stratum corneum “scaffold” with polymers using both natural and model substrates. These studies used vibrational spectroscopy and other physical methods, including surface energy measurements. Most recently, spectroscopic imaging and Raman experiments, coupled to thermal analysis have explored the effects of bleaching on hair structure over periods of exposure. Other areas of study using physical tools included food science, pharmaceuticals (homogeneity with vibrational spectroscopic imaging), and anti-foam technology using vibrational spectroscopy and surface tension measurements.
Books & Chapters