Northeastern Illinois University

Panchatapa Jash, Ph.D.
Instructor

EDUCATION

 

Ph.D., 2009, University of Illinois at Chicago

Thesis: Synthesis, Characterization and Spectroscopic Studies of Some Boron-Containing Hydrogen Storage Materials

 

M.S., 2004, Marquette University, WI

Thesis: Fire Retardancy and Thermal Stability Studies on Poly Methyl Methacrylate-Clay Nanocomposites

 

M.Sc., 2000, Visva-Bharati University, India

Special Paper: Physical Chemistry

 

B.Sc., 1998, Visva-Bharati University, India

Major: Chemistry with Minors: Physics and Mathematics

HIGHLIGHTS ON RESEARCH EXPERIENCE

 

a) Synthesis of Boron-Rich Nanowires

Synthesis of single crystal metal boride nanowires by low pressure chemical vapor deposition (LPCVD) and characterization with transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, electron energy loss spectroscopy (EELS), energy dispersive spectroscopy (EDX), Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS)

 

b) Transmission IR Studies of Hydrogen Storage Materials

Studies of dehydrogenation of metal borohydrides and rehydrogenation of bulk and nanostructured metal borides by Fourier transform infrared spectroscopy (FTIR) under ultra high vacuum (UHV) conditions

 

c) Research on II-VI Semiconductors for IR Detectors

Scanning Auger microprobe and depth profile analysis of cadmium telluride (CdTe) and mercury cadmium telluride (MCT) thin films grown by molecular beam epitaxy (MBE)

 

d) Research on Polymer Clay Nanocomposites

PROFESSIONAL EXPERIENCE

 

a) Post-Doctoral Researcher:   10/2009- To date, UIC

 

b) Research Assistant:   2001-2004 Marquette University                                  2007- 2009, UIC

 

c)Teaching Assistant:    2001-2004 Marquette University                                  2004-2007 U of I, Chicago

 

d)Visiting Student, Northwestern University (05/06-12/06): Advisor Dr. R S Ruoff

TECHNICAL EXPERIENCE

Construction of LPCVD apparatus for synthesis of boron-rich nanostructures; design of a UHV chamber using AutoCAD and assembly of the instrument

SCIENTIFIC PRESENTATIONS

1. “Synthesis and Characterization of Crystalline Strontium Hexaboride Nanowire”

Presented at the Spring Meeting of the American Vacuum Society, Prairie Chapter, June 9th, 2008, Milwaukee, WI

 

2.“Transmission IR Studies of NaBH4 and LiBH4 Dehydrogenation”

Presented at a meeting of the Chicago Catalysis Club, April 15th, 2008, Chicago, IL

 

3.“Transmission IR Studies of NaBH4 and LiBH4 Dehydrogenation”

Presented at the International Symposium on Materials Issues in a Hydrogen Economy, November 12-15th, 2007, Richmond, VA

 

4.  “Dehydrogenation of Boron Nano-Clusters”

Presented at the DOE Hydrogen Contractors Meeting, May 15-18th, 2007, Arlington, VA

PUBLICATIONS

1.  “Transmission IR Studies of Dehydrogenation of BH4- and B12H12-2 Ions”

Panchatapa Jash and Michael Trenary; In Preparation

 

2. “Synthesis and Characterization of Single-Crystal Strontium Hexaboride Nanowires”

Panchatapa Jash, Alan W. Nicholls, Rodney S. Ruoff and Michael Trenary; Nano Lett. 2008, 8 (11), pp 3794–3798

 

3. “Synthesis of crystalline boron nanoribbons and calcium hexaboride by low pressure chemical vapor deposition”

Panchatapa Jash and Michael Trenary; Panchatapa Journal of Physics: Conference Series, 2009, 176, 012011

 

4. “Low Temperature Transmission IR Spectra of Sodium and Lithium Borohydride”

Panchatapa Jash and Michael Ternary, 2009, 130-137, Proceedings of the International Symposium on Materials Issues in a Hydrogen Economy, November 12-15th, 2007, Richmond, VA

 

5. “Synthesis and Characterization of YB66 Nanowires”

S Tan, P Jash and M Trenary, Journal of Undergraduate Research (UIC), 2008, 2 pp 1-7

 

6. “Synthesis and Characterization of Calcium Hexaboride (CaB6) Nanowires”

S Tan, P Jash and M Trenary, Journal of Undergraduate Research (UIC), 2007, 1 p 26-35

 

7. “Fire retardancy of vinyl ester nanocomposites: Synergy with phosphorus-based fire retardants”

Chigwada, Grace; Jash, Panchatapa; Jiang, David D.; Wilkie, Charles A. Polymer Degradation and Stability, 2005, 89(1), pp 85-100.

 

8. “Effects of surfactants on the thermal and fire properties of poly (methyl methacrylate)/clay nanocomposites”   

Jash, Panchatapa, Wilkie, Charles A. Polymer Degradation and Stability, 2005, 88(3), 401-406.

 

9. “Synergy between nanocomposite formation and low levels of bromine in fire retardancy in polystyrenes”

Chigwada, Grace; Jash, Panchatapa; Jiang, David D.; Wilkie, Charles A. Polymer Degradation and Stability, 2005, 88(3), 382-393

 

10. “Recent advances in fire retardancy of polymer-clay nanocomposites”

Wilkie, Charles A.; Costache, Marius C.; Jang, Bok Nam; Jash, Panchatapa, Proceedings of the Conference on Recent Advances in Flame Retardancy of Polymeric Materials, 2004, 15 175-180.

 

11. “Geochemistry of the Laterite: A case study”

Jash, Panchatapa; Abstract of Papers, 2001, p78, XXIInd Conference of Institute of Indian Geographers (IIG) and IGU Commission Meeting on Land Degradation and Desertification.

RESEARCH SUMMARY

I. Metal Boron Complexes: Synthesis, Characterization and Dehydrogenation Studies.

 

Background. Dehydrogenation of borohydrides and higher boranes, for example, decaborane and carborane are of interest because of their applications as the hydrogen storage material. It is challenging to rehydrogenate the dehydrogenated boron hydrogen bond and in order to solve this problem it is necessary to identify the intermediates during the process of dehydrogenation.

 

Dehydrogenation of tetra and dodeca borohydrides. Using transmission IR spectroscopy, we have found that on the way from the BH4- ion to the amorphous boron it first converts to B12H12-2. The intermediate forms start to appear around the melting point in case of NaBH4 evidenced by the formation of peak at around 1260 cm-1. Complete data interpretation is in progress.

 

Synthesis and Characterization of Metal Boride Nanowires. In cases of calcium and some other metal borohydrides metal borides are formed as the end product. Therefore, it can be hypothesize that the rehydrogenation of metal borides would lead to the formation of metal borohydrides, which is a potential hydrogen storage material. At the nanoscale level, due to the higher surface to volume ratio and faster diffusion rate of hydrogen, metal borides are expected to show more efficiency. In order to experience this efficiency, the first step is to successfully synthesize and characterize metal boride nanowires. We have synthesized calcium and strontium hexaboride nanowires, which have applications in thermoelectronic devices as well.

The vapor liquid solid (VLS) mechanism was adopted in the low pressure chemical vapor deposition (LPCVD) synthesis of nanowires. The understanding and the modeling of the synthesis technique is important in the use of this technique for more sophisticated purpose, for example, to make coating on nanowires. We have studied the model of VLS growth mechanism.

 

Surface and Interface Analysis of Thin Films. In order to develop a better quality of semiconductor thin films understanding their surface and the interface properties at the atomistic level is important. The Trenary group is studying the various silicon surfaces and boron rich metal surfaces using scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). Deposition of arsenic surfactant and zinc telluride buffer layer on silicon makes a better quality of molecular beam epitaxial (MBE) growth of cadmium telluride (CdTe). CdTe film finds applications both in the photovoltaic cell and semiconductor industries. The growth of mercury cadmium telluride (MCT) film on CdTe is also feasible. In a collaborative project with the microphysics laboratory of UIC physics department we have studied the CdTe and Si (112) interface using auger electron spectroscopy (AES) and secondary ion mass spectroscopy (SIMS). The aim of this project was not only to meet the opportunity to learn about the MBE, STM and LEED but also to congregate the detailed knowledge on the capabilities of the scanning auger multi-probe (SAM) for the interface analysis of thin films.

 

 

II. Polymer Organo-Clay Nanocomposites.

 

Background. Synthesis of proper surfactants to modify the hydrophilic layered silicate to improve its compatibility with most polymers is important in order to achieve the unique properties and better the dispersion of polymers. The nanoscale dispersion depends on the size and exchange capacity of clays as well as on the choice of surfactants. It is important to discover fire hazard free nanocomposite materials. Fire hazard is related to toxicity, flame spread, heat release and smoke obscuration.

 

Effect of Surfactants on Poly (methyl Methacrylate) and Poly (Styrene)-Clay Nanocomposites. A comparative study among the phosphonium modifier, ammonium modifier and polyhedral oligosilsesquioxanes (POSS) have shown that the insertion of longer chain modifier improves the ignition time of the PMMA-clay nanocomposites but the reinforcement of POSS improves only the thermal stability not the peak heat release rate (PHRR) or the ignition time (tign). PS-clay nanocomposites are well studied but our interest was to find the effect of halogen in the clay on the fire properties. As halogenated compound increase the level of toxicity in smoke, we have added as low as 3% bromine to the polymer chain and the total heat release (THR) was reduced up to 34% with the improvement in flammability properties.

 

Effect of Phosphates on Vinyl Ester-Clay Nanocomposites. Vinyl ester resins are cost effective high performance composites with chemical resistance and excellent mechanical properties. Addition of conventional phosphates improves the PHRR and THR but the tign remains unaffected. However by changing to the compatible clay, tign can be lowered also. Most interestingly it is found that by the proper choice of clay and phosphates the fire retardant properties of vinyl ester resin can perform as good as the benchmark brominated resin.