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Biography

Alvin Joseph Melveger (1937~1993) was an American scientist specializing in physical chemistry, spectroscopy, biomaterials, polymers and other disciplines, Alvin Joseph Melveger has had a long multifaceted career in chemical analysis, research, editing, publishing and teaching.

Melveger graduated from the prestigious, science-oriented Stuyvesant High School in 1955. He received his bachelor's degree in chemistry at Brooklyn College in 1959. He went on to earn a master's degree in chemistry at Northeastern University, Boston, in 1964, and a Doctorate in Physical Chemistry at the University of Maryland in 1968. He was the project manager of funded research programs at The Rutgers University Center of biomaterials and was also the adjunct professor of Chemistry at County College of Morris(1992); and William Paterson University (2003).

Just a few of many other accomplishments and positions held, besides publication in numerous scientific journals, Melveger is a member of the working group on ethylene oxide residues of the American Association for Medical Instrumentation (since 1981); and is a member of the American Association for the Advancement of Science (since 1959).

Other positions were Co-Chairman of the Committee on Education and Training of the New Jersey Research & Development council; Chairman of the American Microchemical Society; and member of the Mount Olive Township (NJ) Environmental Commission (1991—2000). Earlier in his career, Dr. Melveger worked for ALLIED CHEMICAL; the AVCO CORP; and taught at the University of Maryland's Department of Chemistry. And just on a side, Melveger played in the Stuyvesant High School orchestra and band, and has found time to play clarinet in community orchestras.

Major Contributions to Science

• Biomaterials

Alvin Joseph Melveger contributed to the field of biomaterials by conducting research on synthetic absorbable sutures for the applications of wound healing and closing. The main research focus behind the synthetic sutures was to understand the morphological properties of the copolymers as a result of being absorbed by the body during wound closing and healing. The sutures that were investigated consisted of both glycolide and lactide copolymer units. Due to the process of hydrolysis that occurred when the synthetic sutures were in contact with the body, the structural morphologies of the material were investigated to obtain better insight into what occurs to the sutures at the molecular level. From the results, Melveger and coworkers were able to experimentally determine that the sutures tend to favor morphological degradation at the amorphous polymeric regions, which is where the hydrolysis reactions initiate.

• Raman Spectroscopy

Much of Melveger’s research used Raman spectroscopy, a technique to identify molecules by how they scatter monochromatic light. Because this scattering is characteristic of a molecule’s vibrational and rotational modes, it can be used to study the effects of high pressure on molecular bonds. He verified Raman spectroscopy’s usefulness in studying and determining the properties of molecules under high pressure due to its sensitivity.

Melveger verified that Raman spectroscopy is also a useful methodology for determining the isotopic composition of KN¹⁸O₃. Nitrate has a very distinctive Raman pattern because the scattering shifts when the mass of the oxygen atoms vary, but does not depend on the mass of the nitrogen atom. His conclusions acknowledge application beyond that specific molecule, for any quantitative estimate of isotopic oxygen constitution, implying that specifically it would be a good technique for unstable (and by necessity, Raman-active) molecules because it can quickly measure deteriorating molecules.

Melveger also used Raman spectroscopy to observe properties relating to the structure of poly(ethylene terephthalate), discovering that the density correlates with the bandwidth at half maximum intensity of the C=O stretching vibration for both the crystalline and amorphous molecules. His results suggest that rotational modes exist within the amorphous structure, and a planar structure stabilized through resonance exists for the crystallized one.

• Polymer(Poly-ethylene Terephthalate)

Melveger studied on a specific molecule PET(poly-ethylene terephthalate). By incorporating Raman spectroscopy, he made PET band strength(632cm^-1) to be the internal intensity reference point. The magnitude of intensity bands of all other bands such as 1096cm^-1, which is a band that corresponds linearly with density, are all measured relative to the band of PET at 632cm^-1 intensity. This reference facilitates relative measurements, as absolute measurements are difficult to record.^[3] Continuum of his experiments based on testing the different levels of spectrum corresponding to specific structures of the molecule is the main focus of the study. The following paragraphs correspond to the effects on PET’s density and molecular structure.

Relative Raman Intensity vs. density

Melveger discovered that the correlation between Raman intensity and density(PET) changes with the orientation of PET. There are two different tests: one on heat-crystallized PET samples having no orientation and the other on a series of PET fibers. The heat-crystallized PET showed the linear relationship that was aforementioned, whereas the latter showed non-linear dispersed data points. So there was a problem in relating the Raman intensity to densities of all different structures of PET. Rather, Melveger found out that the orientation or crstallinity of PET plays a significant role of the Raman intensity vs. density.

Another experiment is to measure density with half intensity bandwidth. Surprisingly, this method did not depend on the orientation in the sample. So for all different orientations of PET, the 1/2 bandwidth vs density graph showed a linear relationship. Also, this method does not require internal intensity standard and the measurement may be used for any type of PET sample. The bandwidth measurement correlates well with total density whereas the Raman intensity does not for oriented samples. This correlation is evidence that the bandwidth is a measure of total order in the system.

Reference

1. wiki.riteme.site/wiki/Alvin_Joseph_Melveger

2. Fredericks, R. J., Melveger, A. J. and Dolegiewitz, L. J. (1984), Morphological and structural changes in a copolymer of glycolide and lactide occurring as a result of hydrolysis. J. Polym. Sci. Polym. Phys. Ed., 22: 57–66. doi:10.1002/pol.1984.180220106

3. Brasch, J. W.; Melveger, A. J.; Lippincott, E. R. (1968-06-01). "Laser excited Raman spectra of samples under very high pressures". Chemical Physics Letters. 2: 99–100. doi:10.1016/0009-2614(68)80059-4. ISSN 0009-2614.

4.  Melveger, A. J.; Johnson, E. R.; Ladov, E. N. (1970-01-01). "Determination of 18O isotopic constitution of oxy-anions using Raman scattering". Journal of Inorganic and Nuclear Chemistry. 32 (1): 337–339. doi:10.1016/0022-1902(70)80477-8.

5.  Melveger, A. J. (1972-02-01). "Laser-raman study of crystallinity changes in poly(ethylene terephthalate)". Journal of Polymer Science Part A-2: Polymer Physics. 10 (2): 317–322. doi:10.1002/pol.1972.160100211. ISSN 1542-9377