Steve Wolpert | Rutgers Preparatory School (original) (raw)
Papers by Steve Wolpert
Journal of Membrane Science, Aug 20, 1997
An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, t... more An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, through casting dope formulation, and finally membrane casting. Aldehyde functionality, introduced through acrolein, provided activation by Schiff base formation with proteins. Acrolein copolymers and their affinity applications were reviewed. Solution polymerization of acrolein and acrylonitrile produced a copolymer of sufficient mechanical strength to constitute a casting dope. Membranes cast from DMSO by the phase inversion process proved microporous when allowed to gel in warm (40-50°C), humid air. Membranes cast from other solvents or at ambient temperature or those immersed directly under water were all tighter. No other supporting non-functional membrane was needed, although a scrim reinforcement improved robustness. Protein-binding studies using alkaline phosphatase enzyme and enzyme-linked immunoassay (ELISA) studies using an IgG antibody-antigen complex were conducted. After various extensive washings to remove unbound protein, the polyaldehyde membranes were demonstrated to be comparable to the commercially available affinity membrane controls.
Journal of polymer science, Oct 1, 1971
Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, ... more Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, poly(methy1 methacrylate), and poly(2,6-diiethyl-1,4-phenylene ether) in the glass transition region were determined by differential thermal analysis. The thermal history was set by linear cooling a t rates between 0.007 and 16OoC/min. Linear heating for analysis was carried out at rates between 0.3 and 6OO0C/min. Average activation energies of 52,81,90,54,77, and 108 kcal/mole, respectively, were evaluated by using the hole theory of glasses previously developed. Within experimental limitations all data could be described quantitatively by the theoretical expressions using only one parameter, the number of frozen-in holes, to describe the thermal history. Experimental and theoretical limitations are discussed. Measurements of heat capacity of amorphous materials in the glass transition region show nonequilibrium effects due mainly to time-dependent configurational rearrangements of the molecules. At temperatures sufficiently below the glass transition T,, the configuration is virtually frozen in, and the heat capacity of the glass behaves like an equilibrium property. Frequently, the heat capacity of glasses is similar to heat capacity of equilibrium crystals of chemically identical structures down to temperatures as low as 50°K. At temperatures sufficiently above T,, the configurational rearrangements are so fast that their time dependence is not measurable, and an equilibrium heat capacity exists for the melt. The heat capacity contribution due to changes in mode of motion (such as vibrations changing to rotation or translation) is much smaller than that due to configurational rearrangements (such as hole formation) in the T, region. This paper will be concerned with the time-dependent apparent heat capacity of six materials in the glass transition region: glucose (CSHIZO~), selenium (Se), poly(viny1 chloride) (PVC), polystyrene (PS), poly(methy1 methacrylate) (PMMA), and poly(2,6-dimethyl-l,4phenyl ether) (PPO). Early observations of heat capacity as a function of time and temperature established that a maximum and a minimum can occur in the transition region of several organic, inorganic, and polymeric Presently
Birkhäuser Basel eBooks, 1972
Differential thermal analysis has special value for the analysis of metastable states. In order t... more Differential thermal analysis has special value for the analysis of metastable states. In order to establish the thermal properties quickly, fast DTA is necessary. In prior ICTA meetings the study of slow melting polymer crystals above the melting temperature was reported (1). Present work deals with the fast DTA of glasses in their transition region. Calculations of the temperature gradient in cylindrical DTA cells revealed that typically 1 g samples can be analyzed with negligible gradient within the sample with 1–10°C/min heating rates. Cutting the size to 1 mg, the heating rates can be increased to 100–1000°C/min. Extrapolations would indicate that microgram samples could be heated with 104–105°C/min heating rates. Detailed theoretical analyses of the DTA-curves as a function of changes in heat capacity at different heating rates are reported and experimental verification on the glass transitions of glucose, selenium, polystyrene, poly(methyl methacrylate), poly(vinyl chloride) and poly(2,6-dimethyl 1,4-phenylene ether) are given.
Analytical Chemistry, Dec 3, 1998
Membranes microporeuses de filtration utiles pour absorber ou adsorber des atomes, des molecules ... more Membranes microporeuses de filtration utiles pour absorber ou adsorber des atomes, des molecules ou des particules cationiques de liquides ou de gaz. L'invention concerne egalement de nouvelles solutions copolymeres fortement acides capables de reticulation, ainsi qu'un procede de preparation de telles solutions et de production a partir de ces solutions de membranes microporeuses fortement acides ou anioniques a charge modifiee de filtration. Le copolymere des solutions est synthetise a partir de l'acide 2-acrylamido-2-methyle-1-propanesulphonique (ANPS) et soit de N-(isobutoxymethyle)acrylamide (IBMA) soit de 2-hydroxyethyle methacrylate (HEMA).
Journal of Polymer Science Part A-2: Polymer Physics, 1971
Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, ... more Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, poly(methy1 methacrylate), and poly(2,6-diiethyl-1,4-phenylene ether) in the glass transition region were determined by differential thermal analysis. The thermal history was set by linear cooling a t rates between 0.007 and 16OoC/min. Linear heating for analysis was carried out at rates between 0.3 and 6OO0C/min. Average activation energies of 52,81,90,54,77, and 108 kcal/mole, respectively, were evaluated by using the hole theory of glasses previously developed. Within experimental limitations all data could be described quantitatively by the theoretical expressions using only one parameter, the number of frozen-in holes, to describe the thermal history. Experimental and theoretical limitations are discussed. Measurements of heat capacity of amorphous materials in the glass transition region show nonequilibrium effects due mainly to time-dependent configurational rearrangements of the molecules. At temperatures sufficiently below the glass transition T,, the configuration is virtually frozen in, and the heat capacity of the glass behaves like an equilibrium property. Frequently, the heat capacity of glasses is similar to heat capacity of equilibrium crystals of chemically identical structures down to temperatures as low as 50°K. At temperatures sufficiently above T,, the configurational rearrangements are so fast that their time dependence is not measurable, and an equilibrium heat capacity exists for the melt. The heat capacity contribution due to changes in mode of motion (such as vibrations changing to rotation or translation) is much smaller than that due to configurational rearrangements (such as hole formation) in the T, region. This paper will be concerned with the time-dependent apparent heat capacity of six materials in the glass transition region: glucose (CSHIZO~), selenium (Se), poly(viny1 chloride) (PVC), polystyrene (PS), poly(methy1 methacrylate) (PMMA), and poly(2,6-dimethyl-l,4phenyl ether) (PPO). Early observations of heat capacity as a function of time and temperature established that a maximum and a minimum can occur in the transition region of several organic, inorganic, and polymeric Presently
Analytical Chemistry, 1999
Journal of Membrane Science, 1997
An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, t... more An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, through casting dope formulation, and finally membrane casting. Aldehyde functionality, introduced through acrolein, provided activation by Schiff base formation with proteins. Acrolein copolymers and their affinity applications were reviewed. Solution polymerization of acrolein and acrylonitrile produced a copolymer of sufficient mechanical strength to constitute a casting dope. Membranes cast from DMSO by the phase inversion process proved microporous when allowed to gel in warm (40-50°C), humid air. Membranes cast from other solvents or at ambient temperature or those immersed directly under water were all tighter. No other supporting non-functional membrane was needed, although a scrim reinforcement improved robustness. Protein-binding studies using alkaline phosphatase enzyme and enzyme-linked immunoassay (ELISA) studies using an IgG antibody-antigen complex were conducted. After various extensive washings to remove unbound protein, the polyaldehyde membranes were demonstrated to be comparable to the commercially available affinity membrane controls.
Advances in Instrumentation, 1972
Journal of Membrane Science, Aug 20, 1997
An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, t... more An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, through casting dope formulation, and finally membrane casting. Aldehyde functionality, introduced through acrolein, provided activation by Schiff base formation with proteins. Acrolein copolymers and their affinity applications were reviewed. Solution polymerization of acrolein and acrylonitrile produced a copolymer of sufficient mechanical strength to constitute a casting dope. Membranes cast from DMSO by the phase inversion process proved microporous when allowed to gel in warm (40-50°C), humid air. Membranes cast from other solvents or at ambient temperature or those immersed directly under water were all tighter. No other supporting non-functional membrane was needed, although a scrim reinforcement improved robustness. Protein-binding studies using alkaline phosphatase enzyme and enzyme-linked immunoassay (ELISA) studies using an IgG antibody-antigen complex were conducted. After various extensive washings to remove unbound protein, the polyaldehyde membranes were demonstrated to be comparable to the commercially available affinity membrane controls.
Journal of polymer science, Oct 1, 1971
Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, ... more Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, poly(methy1 methacrylate), and poly(2,6-diiethyl-1,4-phenylene ether) in the glass transition region were determined by differential thermal analysis. The thermal history was set by linear cooling a t rates between 0.007 and 16OoC/min. Linear heating for analysis was carried out at rates between 0.3 and 6OO0C/min. Average activation energies of 52,81,90,54,77, and 108 kcal/mole, respectively, were evaluated by using the hole theory of glasses previously developed. Within experimental limitations all data could be described quantitatively by the theoretical expressions using only one parameter, the number of frozen-in holes, to describe the thermal history. Experimental and theoretical limitations are discussed. Measurements of heat capacity of amorphous materials in the glass transition region show nonequilibrium effects due mainly to time-dependent configurational rearrangements of the molecules. At temperatures sufficiently below the glass transition T,, the configuration is virtually frozen in, and the heat capacity of the glass behaves like an equilibrium property. Frequently, the heat capacity of glasses is similar to heat capacity of equilibrium crystals of chemically identical structures down to temperatures as low as 50°K. At temperatures sufficiently above T,, the configurational rearrangements are so fast that their time dependence is not measurable, and an equilibrium heat capacity exists for the melt. The heat capacity contribution due to changes in mode of motion (such as vibrations changing to rotation or translation) is much smaller than that due to configurational rearrangements (such as hole formation) in the T, region. This paper will be concerned with the time-dependent apparent heat capacity of six materials in the glass transition region: glucose (CSHIZO~), selenium (Se), poly(viny1 chloride) (PVC), polystyrene (PS), poly(methy1 methacrylate) (PMMA), and poly(2,6-dimethyl-l,4phenyl ether) (PPO). Early observations of heat capacity as a function of time and temperature established that a maximum and a minimum can occur in the transition region of several organic, inorganic, and polymeric Presently
Birkhäuser Basel eBooks, 1972
Differential thermal analysis has special value for the analysis of metastable states. In order t... more Differential thermal analysis has special value for the analysis of metastable states. In order to establish the thermal properties quickly, fast DTA is necessary. In prior ICTA meetings the study of slow melting polymer crystals above the melting temperature was reported (1). Present work deals with the fast DTA of glasses in their transition region. Calculations of the temperature gradient in cylindrical DTA cells revealed that typically 1 g samples can be analyzed with negligible gradient within the sample with 1–10°C/min heating rates. Cutting the size to 1 mg, the heating rates can be increased to 100–1000°C/min. Extrapolations would indicate that microgram samples could be heated with 104–105°C/min heating rates. Detailed theoretical analyses of the DTA-curves as a function of changes in heat capacity at different heating rates are reported and experimental verification on the glass transitions of glucose, selenium, polystyrene, poly(methyl methacrylate), poly(vinyl chloride) and poly(2,6-dimethyl 1,4-phenylene ether) are given.
Analytical Chemistry, Dec 3, 1998
Membranes microporeuses de filtration utiles pour absorber ou adsorber des atomes, des molecules ... more Membranes microporeuses de filtration utiles pour absorber ou adsorber des atomes, des molecules ou des particules cationiques de liquides ou de gaz. L'invention concerne egalement de nouvelles solutions copolymeres fortement acides capables de reticulation, ainsi qu'un procede de preparation de telles solutions et de production a partir de ces solutions de membranes microporeuses fortement acides ou anioniques a charge modifiee de filtration. Le copolymere des solutions est synthetise a partir de l'acide 2-acrylamido-2-methyle-1-propanesulphonique (ANPS) et soit de N-(isobutoxymethyle)acrylamide (IBMA) soit de 2-hydroxyethyle methacrylate (HEMA).
Journal of Polymer Science Part A-2: Polymer Physics, 1971
Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, ... more Timedependent, apparent heat capacities of glucose, poly(viny1 chloride), polystyrene, selenium, poly(methy1 methacrylate), and poly(2,6-diiethyl-1,4-phenylene ether) in the glass transition region were determined by differential thermal analysis. The thermal history was set by linear cooling a t rates between 0.007 and 16OoC/min. Linear heating for analysis was carried out at rates between 0.3 and 6OO0C/min. Average activation energies of 52,81,90,54,77, and 108 kcal/mole, respectively, were evaluated by using the hole theory of glasses previously developed. Within experimental limitations all data could be described quantitatively by the theoretical expressions using only one parameter, the number of frozen-in holes, to describe the thermal history. Experimental and theoretical limitations are discussed. Measurements of heat capacity of amorphous materials in the glass transition region show nonequilibrium effects due mainly to time-dependent configurational rearrangements of the molecules. At temperatures sufficiently below the glass transition T,, the configuration is virtually frozen in, and the heat capacity of the glass behaves like an equilibrium property. Frequently, the heat capacity of glasses is similar to heat capacity of equilibrium crystals of chemically identical structures down to temperatures as low as 50°K. At temperatures sufficiently above T,, the configurational rearrangements are so fast that their time dependence is not measurable, and an equilibrium heat capacity exists for the melt. The heat capacity contribution due to changes in mode of motion (such as vibrations changing to rotation or translation) is much smaller than that due to configurational rearrangements (such as hole formation) in the T, region. This paper will be concerned with the time-dependent apparent heat capacity of six materials in the glass transition region: glucose (CSHIZO~), selenium (Se), poly(viny1 chloride) (PVC), polystyrene (PS), poly(methy1 methacrylate) (PMMA), and poly(2,6-dimethyl-l,4phenyl ether) (PPO). Early observations of heat capacity as a function of time and temperature established that a maximum and a minimum can occur in the transition region of several organic, inorganic, and polymeric Presently
Analytical Chemistry, 1999
Journal of Membrane Science, 1997
An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, t... more An affinity membrane was designed for manufacturability, starting from novel polymer synthesis, through casting dope formulation, and finally membrane casting. Aldehyde functionality, introduced through acrolein, provided activation by Schiff base formation with proteins. Acrolein copolymers and their affinity applications were reviewed. Solution polymerization of acrolein and acrylonitrile produced a copolymer of sufficient mechanical strength to constitute a casting dope. Membranes cast from DMSO by the phase inversion process proved microporous when allowed to gel in warm (40-50°C), humid air. Membranes cast from other solvents or at ambient temperature or those immersed directly under water were all tighter. No other supporting non-functional membrane was needed, although a scrim reinforcement improved robustness. Protein-binding studies using alkaline phosphatase enzyme and enzyme-linked immunoassay (ELISA) studies using an IgG antibody-antigen complex were conducted. After various extensive washings to remove unbound protein, the polyaldehyde membranes were demonstrated to be comparable to the commercially available affinity membrane controls.
Advances in Instrumentation, 1972