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Dive into the research topics where Morton H. Litt is active.

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Featured researches published by Morton H. Litt.


Journal of The Electrochemical Society | 1995

Acid doped polybenzimidazoles, a new polymer electrolyte

Jesse S. Wainright; J.‐T. Wang; D. Weng; Robert F. Savinell; Morton H. Litt

Polybenzimidazole films doped with phosphoric acid are being investigated as potential polymer electrolytes for use in hydrogen/air and direct methanol fuel cells. In this paper, we present experimental findings on the proton conductivity, water content, and methanol vapor permeability of this material, as well as preliminary fuel cell results. The low methanol vapor permeability of these electrolytes significantly reduces the adverse effects of methanol crossover typically observed in direct methanol polymer electrolyte membrane fuel cells.


Journal of The Electrochemical Society | 2004

Conductivity of PBI Membranes for High-Temperature Polymer Electrolyte Fuel Cells

Y.-L. Ma; Jesse S. Wainright; Morton H. Litt; Robert F. Savinell

Polybenzimidazole (PB1) film, a candidate polymer electrolyte membrane (PEM) for high-temperature (120-200°C) fuel cells, was cast from PBI/trifluoacetyl/H 3 PO 4 solution with constant molecular weight PBI powder and various acid doping levels. Conductivity measurements on these membranes were performed using an ac method under controlled temperature and relative humidity (RH). A complete set of conductivity data for H 3 PO 4 acid-doped PBI is presented as a function of temperature (60-200°C), RH (5-30%), and acid doping level (300-600 mol %). A mechanism of conductivity is proposed for the proton migration in this PBI/acid system based on this and previous work. Proton transfer in this system appears to occur along different paths for different doping levels, RHs, and temperatures. Hydrogen bonds immobilize the anions and form a network for proton transfer by a Grotthuss mechanism. The rate of proton transfer involving H 2 O is faster, leading to higher conductivity at higher RH. The order of the rate of proton transfer between various species is H 3 PO 4 (H 2 PO 4 -)...H-O-H> H 3 PO 4 ...H 2 PO - 4 > N-H + ...H 2 PO 4 - + N-H + ...H-O-H > N-H + ...N-H. The upper limit of proton conductivity is given by the conductivity of the liquid state H 3 PO 4 .


Electrochimica Acta | 1996

A H2O2 fuel cell using acid doped polybenzimidazole as polymer electrolyte

J.‐T. Wang; Robert F. Savinell; Jesse S. Wainright; Morton H. Litt; H. Yu

Phosphoric acid doped polybenzimidazole (PBI-poly[2,2′-(m-phenylene)-5,5′-bibenzimidazole]) has been investigated for use in a H2O2 fuel cell. The prototype fuel cell test results show that the PBI fuel cell worked quite well at 150 °C with atmospheric pressure hydrogen and oxygen which were humidified at room temperature. No membrane dehydration was observed over 200 h operating. The maximum power density of this prototype fuel cell was 0.25 W cm−2 at current density of 700 mA cm2. Further improvement of the cell performance is to be anticipated by properly impregnating the electrode structure with the polymer electrolyte. The advantage of the H2O2 fuel cell using PBI as polymer electrolyte is that the cell design and the routine maintenance can be significantly simplified because of the low electro-osmotic drag number and good proton conductivity of the PBI membrane at elevated temperature.


Journal of The Electrochemical Society | 1994

A Polymer Electrolyte for Operation at Temperatures up to 200°C

Robert F. Savinell; E. Yeager; D. Tryk; Uziel Landau; Jesse S. Wainright; D. Weng; K. Lux; Morton H. Litt; Charles E. Rogers

In developing advanced fuel cells and other electrochemical reactors, it is desirable to combine the advantages of solid polymer electrolytes with the enhanced catalytic activity associated with temperatures above 100 C. This will require polymer electrolytes which retain high ionic conductivity at temperatures above the boiling point of water. One possibility is to equilibrate standard perfluorosulfonic acid polymer electrolytes such as Nafion, with a high boiling point Bronsted base such as phosphoric acid. The Nafion/H[sub 3]PO[sub 4] electrolyte has been evaluated with respect to water content, ionic conductivity and transport of oxygen, and methanol vapor. The results show that at elevated temperatures reasonably high conductivity (>0.05 [Omega][sup [minus]1] cm[sup [minus]1]) can be obtained. Methanol permeability is shown to be proportional to the methanol vapor activity and thus decreases with increasing temperature for a given partial pressure. Comparisons and distinctions between this electrolyte and pure phosphoric acid are also considered.


Journal of Applied Electrochemistry | 1996

A direct methanol fuel cell using acid-doped polybenzimidazole as polymer electrolyte

J. T. Wang; Jesse S. Wainright; Robert F. Savinell; Morton H. Litt

A direct methanol/oxygen solid polymer electrolyte fuel cell was demonstrated. This fuel cell employed a 4 mg cm−2 Pt-Ru alloy electrode as an anode, a 4 mg cm−2 Pt black electrode as a cathode and an acid-doped polybenzimidazole membrane as the solid polymer electrolyte. The fuel cell is designed to operate at elevated temperature (200°C) to enhance the reaction kinetics and depress the electrode poisoning, and reduce the methanol crossover. This fuel cell demonstrated a maximum power density about 0.1 W cm−2 in the current density range of 275–500 mA cm−2 at 200°C with atmospheric pressure feed of methanol/water mixture and oxygen. Generally, increasing operating temperature and water/methanol mole ratio improves cell performance mainly due to the decrease of the methanol crossover. Using air instead of the pure oxygen results in approximately 120 mV voltage loss within the current density range of 200–400 mA cm−2 .


Electrochimica Acta | 2003

Microfabricated fuel cells

Jesse S. Wainright; Robert F. Savinell; Chung-Chiun Liu; Morton H. Litt

One or more microfabricated fuel cells may be integrated into a printed circuit board or a printed wiring board within an electronic device. The electrical energy created by the integrated microfabricated fuel cells within the metal wiring on the PWB may then be used by the electronic components within and on the PWB.


Journal of Applied Physics | 1971

Superparamagnetism and Exchange Anisotropy in Microparticles of Magnetite Embedded in an Inert Carbonaceous Matrix

Shaul M. Aharoni; Morton H. Litt

By the controlled thermal degradation of ferricinium nitrate a material composed of iron oxide particles embedded in an inert carbonaceous matrix was obtained. The iron oxide particles were found to be mostly magnetite, and their average diameter about 35 A. This value was obtained from both x‐ray diffraction line broadening and from static magnetic measurements. The small particle size caused the material to be superparamagnetic down to and below liquid‐nitrogen temperature. At liquid‐helium temperature the material was ferromagnetic and exhibited exchange anisotropy in the form of a shifted hysteresis loop. A coupling energy of 2.28×105 erg/cm3 was calculated from the shifted hysteresis loop. EPR and Mossbauer‐effect spectra showed electron hopping at room temperature within the Fe3O4. In the ferromagnetic state, local disorder around the magnetic ions manifests itself as broadening of the Mossbauer spectra and displacement of the hysteresis loop.


ACS Applied Materials & Interfaces | 2015

Achieving High Dielectric Constant and Low Loss Property in a Dipolar Glass Polymer Containing Strongly Dipolar and Small-Sized Sulfone Groups

Junji Wei; Zhongbo Zhang; Jung-Kai Tseng; Imre Treufeld; Xiaobo Liu; Morton H. Litt; Lei Zhu

In this report, a dipolar glass polymer, poly(2-(methylsulfonyl)ethyl methacrylate) (PMSEMA), was synthesized by free radical polymerization of the corresponding methacrylate monomer. Due to the large dipole moment (4.25 D) and small size of the side-chain sulfone groups, PMSEMA exhibited a strong γ transition at a temperature as low as -110 °C at 1 Hz, about 220 °C below its glass transition temperature around 109 °C. Because of this strong γ dipole relaxation, the glassy PMSEMA sample exhibited a high dielectric constant of 11.4 and a low dissipation factor (tan δ) of 0.02 at 25 °C and 1 Hz. From an electric displacement-electric field (D-E) loop study, PMSEMA demonstrated a high discharge energy density of 4.54 J/cm(3) at 283 MV/m, nearly 3 times that of an analogue polymer, poly(methyl methacrylate) (PMMA). However, the hysteresis loss was only 1/3-1/2 of that for PMMA. This study suggests that dipolar glass polymers with large dipole moments and small-sized dipolar side groups are promising candidates for high energy density and low loss dielectric applications.


Journal of Applied Physics | 1977

Pyroelectricity and piezoelectricity in nylon 11

Morton H. Litt; Che‐hsiung Hsu; P. Basu

This paper describes preliminary pyroelectric and piezoelectric results obtained with commercial films of nylon 11. The results of dielectric‐constant measurements in the temperature range 20–130 °C are also presented. Nylon 11 films show quite high pyroelectricity and the evidence indicates that there is probably dipole orientation in crystalline regions. Charge injection or volume polarization, as well as dipole orientation, was shown to contribute to the pyroelectricity unless the sample was thoroughly relaxed.


Journal of Materials Chemistry | 2012

Synthesis and characterization of poly(para-phenylene disulfonic acid), its copolymers and their n-alkylbenzene grafts as proton exchange membranes: high conductivity at low relative humidity

Kun Si; Daxuan Dong; Ryszard Wycisk; Morton H. Litt

Water insoluble poly(para-phenylene disulfonic acid) and its copolymers were synthesized by direct polymerization of 1,4-dibromobenzene-2,5-disulfonic acid and 4,4′-dibromobiphenyl-3,3′-disulfonic acid lithium salts using Ullmann coupling and subsequent grafting of long-tail alkylbenzene groups onto the polymer backbones. Copolymers with ion exchange capacities of 4.3 to 7.7 meq. g−1 were obtained. Polymers and copolymers prepared under optimized polymerization conditions were characterized by NMR, TGA, DSC and viscometry. The physicochemical characteristics of the copolymers were tailored by adjusting monomer compositions and by varying the grafting reaction temperature and time. These polymers could hold eight or more strongly bound water molecules per acid group, which facilitated their high conductivity. In the dry state, the polymers were very brittle. Membranes prepared from these polymers exhibited proton conductivity as much as ten times higher than that of Nafion® 212, at elevated temperature and low relative humidity.

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Robert F. Savinell

Case Western Reserve University

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Charles E. Rogers

Case Western Reserve University

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Lei Zhu

Case Western Reserve University

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Jesse S. Wainright

Case Western Reserve University

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Zhongbo Zhang

Case Western Reserve University

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Anastasios P. Melissaris

Case Western Reserve University

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Gangfeng Cai

Case Western Reserve University

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Jerome B. Lando

Case Western Reserve University

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Navzer D. Sachinvala

Agricultural Research Service

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Shaul M. Aharoni

Case Western Reserve University

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