lenses
UNLV Logo
UNLV Mascot  

Dr. Kris Lipinska

Associate Research Professor

Department of Mechanical Engineering

  | HOME | NEWS | LABS | RESEARCH | JOBS | PAPERS | TALKS | PEOPLE | TEACHING | GRANTS | COLLABORATIONS | GALLERY |
   
 

RESEARCH PROJECTS

Dr. Lipinska's research revolves around synthesis and characterization of glasses, ceramics and glass ceramic materials for optical and other applications, examining the role of structure/property relationships on resulting performance. The goals are understanding of physico-chemical phenonema and leveraging those links to improve materials' performance.

lumi mapping   NANO-STRUCTURED GLASS-BASED COMPOSITES
| UNLV |


Nanocrystalline glass-ceramic composites combine the best of the crystal and glass ‘worlds’ and display features of glasses and crystals in one material, offer flexibility of composition, tunability of properties and provide a wide spectrum of technological advantages over conventional glasses or polycrystalline ceramics. Their wide ranging applications include: telescope mirrors supports, laser gyroscopes, radiant stovetops, teeth and bone implants, super-hard materials, zero-thermal expansion elements, tunable lasers, luminescent solar concentrators, light-emitting media, tunable lasers, luminescent solar concentrators, and so on.

We fabricate nanocrystalline glass-ceramic composites and we study their physico-chemical properties. We focus on controlled synthesis, that is nucleation and growth kinetics of nanocrystals of semiconductor, metal or insulator type, grown embedded in the ‘parent’ glass media as well as on investigations of their structural, optical and thermal properties. The goal is to tune the optical and physical properties of these materials ‘on demand’ using external forces (temperature, radiation etc) or internally, through compositional modifications.

glasses and nanocomposites
  OPTICAL PROPERTIES OF GLASSES & GLASS CERAMICS
| UNLV | Illinois Institute of Technology| Advanced Photon Source - ANL |


The current demand in optical communication technology is to look for efficient, low-cost optoelectronic functions (ex. signal transmission and amplification) in the form of novel materials. The myriad of applications include next generation media for planar or fiber optical amplifiers as well as laser materials or energy up-conversion media.

In this project we explore doping by optically active ions to modify the optical properties of oxide glasses and glass-nanocrystal composites (glass-ceramics). The latter combine glass and crystal characteristics and offer, for optically active ions, an attractive, alternative environment to that of a pure glass or of a pure crystal. A key advantage is that glass-ceramic materials are composites still based on glass, so they are compatible and can be easily combined with optical fibers used by the telecom industry.

This research builds upon our findings of new vitroceramic media for efficient light amplification (optical amplifiers). Our investigations focus on the understanding of the local structure of luminescent rare earths in new host glass matrices, with the ultimate goal to be able to tailor the materials’ radiative emission properties through the preparation of host matrices with variable microstructures and compositions. The objective is to fill significant gaps in the current knowledge of correlation between composition of material, its microstructure and rare earth clustering and the effect of photodarkening.

H2 StaorageDOE Hydrogen Program
  GLASSES & NANOCOMPOSITES FOR HYDROGEN STORAGE
| UNLV |

The most desirable materials for hydrogen storage do not interact chemically with hydrogen and possess a high surface area to host substantial amounts of hydrogen. Other desirable engineering characteristics are low cost, environmental friendliness and eliminating explosion risks.

Our project encompasses fundamental research into physics of glasses and nanocrystalline composite materials, derived from glass. Key advantages of these materials are: flexibility of composition, durability & strength, environmental friendliness and low cost. Glasses are built of disordered networks with ample void spaces that make them permeable to hydrogen even at room temperature. We engineer glass materials, modyfying them with functional dopants and explore how manipulating voids in glass networks could open doors for new material’s functionalities in respect to hydrogen storage.

We patented a new process for use in H-storage technology. The patent addresses selection of new glass systems and glass compositions and identification of new processes as well as development of novel techniques allowing for fast and effective hydrogen permeation through the wall of a glass microsphere, which would permit to eliminate the existing barriers for hydrogen diffusion.

HP RamanHP XRDtwo diamondshole in gasketDAC Closed

  MULLITE-TYPE OXIDES AT HIGH-PRESSURES: MICROSTRUCTURAL IMPLICATIONS
| UNLV | U. BREMEN, Germany| Advanced Photon Source - ANL |


Even though Al2O3-SiO2 mullite occurs rarely in nature, it is perhaps one of the most important phases in both traditional and advanced ceramics. Applications of mullite-type materials include: high-temperature composites, aerospace materials, ballistic shielding for military applications and even non-linear optical materials. There remain many uncertainties regarding the basic physical properties of mullite-type ceramics, particularly in terms of its high-pressure phase stability and mechanical behavior.

In this project we investigate mullites and synthetic mullite-type oxides and how their most fundamental building blocks accommodate high pressure compression. Our studies of pressure-induced structural changes of mullite and mullite-type materials contribute to the in-depth fundamental understanding of the crystal chemistry of mullite-type ceramics and can lead to the design of new types of mullites for extreme environment applications.

Our key findings are: phase transitions, equations of state, pressure-driven amorphization, and the very rare effect of negative linear compressibility. Our unprecedented discovery of negative linear compressibility in mullite-type oxides opens the door to military applications as incompressible optical materials.

Biofuels Images   CERAMICS MEMBRANES APPLIED IN PRODUCTION OF BIOFUELS
| UNLV | Ceramatec Inc. - CoorsTek | Rensselaer Polytechnic Institute |


To produce biofuels from vegetable oils, animal fats and recycled greases it is necessary to use a chemical called Sodium Methoxide (SMO). SMO is used to catalyze the transformation of edible and non-edible oils and greases into biofuels.
Most of SMO is imported into the U.S. and commonly used methods to produce SMO are all energy intensive and environmentally hazardous.

This R&D project develops, demonstrates and deploys a new electrochemical membrane process, to produce high-purity SMO. Our project uses Na super ionic conductor ceramics (NaSICON) as membrane materials at the heart of an electrochemical cell that synthesizes high-purity SMO from low-cost aqueous sodium hydroxide and methanol.

Several strategies are followed to extend the ceramic membrane’s lifetime and increase performance and process economics: development of new ceramic membrane compositions, altering of the fabrication route, fabrication of coatings as well as development of new cell configurations to give better performance and reduced energy consumption.

 
 
 
 
     © 2015, Kris Lipinska, University of Nevada Las Vegas. All rights reserved.