Tools

LEADER 04175cam 2200577Ia 4500

001 ocn747859949;

003 OCoLC;

005 20141212070852.0;

006 m d ;

007 cr bn|||||||||;

008 110825s2011 ncua ob 000 0 eng d;

035 a| (Sirsi) o747859949;

035 a| (OCoLC)747859949;

040 a| EREc| EREd| EREd| UtOrBLW;

049 a| EREE;

090 a| QD96.M3;

100 1 a| Williams, Christopher M.?| UNAUTHORIZED;

245 10 a| Electrospray ionization time of flight mass spectrometry of poly(methyl methacrylate) and polystyrene using surface active quaternary ammonium salts /c| by Christopher M. Williams.;

260 a| [Greenville, N.C.] :b| East Carolina University,c| 2011.;

300 a| 83 pages :b| illustrations (some color), digital, PDF file;

336 a| text2| rdacontent;

337 a| computer2| rdamedia;

338 a| online resource2| rdacarrier;

538 a| System requirements: Adobe Reader.;

538 a| Mode of access: World Wide Web.;

502 b| M.A.c| East Carolina Universityd| 2011.;

500 a| Presented to the faculty of the Department of Chemistry.;

500 a| Advisor: Timothy Romack.;

500 a| Title from PDF t.p. (viewed Oct. 20, 2011).;

520 3 a| Electrospray ionization time of flight mass spectrometry (ESI-ToF-MS) is a powerful characterization technique for large nonvolatile compounds, but has found limited applicability in the synthetic polymer field. Two factors currently limit the utility of ESI-ToF-MS for synthetic polymer characterization: 1) Electrospray ionization often results in multiply charged species for each component in the sample. Synthetic polymers contain a distribution of many compounds with close, uniformly spaced masses. The presence of multiple m/z peaks for each mass typically results in data that is complicated and becomes increasingly complicated as the average molar mass of the sample increases. 2) Electrospray ionization is best suited for polar, easily ionized species dissolved in polar solvents. The vast majority of synthetic polymers are relatively non-polar, do not ionize easily and are not soluble in the polar solvents most often used for ESI. By adding easily ionizable, surface active quaternary ammonium salts that associate with polymer molecules during ionization, we have made significant strides in overcoming both of these limitations. By using cetyltrimethylammonium bromide (CTAB) as an additive, we have been able to produce ESI-MS spectra with only singly charged charge states for the entire m/z range observable by our instrument (m/z = 0 - 20,000). Data will be presented for poly(methyl methacrylate) and polystyrene samples. Weight averaged molecular weight (Mw), number averaged molecular weight (Mn) and polydispersity (PD) calculations were all in good agreement with comparative analysis using Gel Permeation Chromatography (GPC) and Gel Permeation Chromatography - Multi-Angle Light Scattering (GPC-MALS). Further, for some samples, multiple distributions were identified corresponding to different end groups highlighting the utility of this approach.;

504 a| Includes bibliographical references.;

650 0 a| Electrospray ionization mass spectrometry.=| ^A494485;

650 0 a| Mass spectrometry.=| ^A6834;

650 0 a| Time-of-flight mass spectrometry.=| ^A538239;

650 0 a| Polymethylmethacrylate.=| ^A685088;

650 0 a| Polystyrene.=| ^A692519;

650 0 a| Polymers.=| ^A10854;

650 0 a| Quaternary ammonium salts.=| ^A1012197;

650 0 a| Surface active agents.=| ^A99520;

653 a| Organic Chemistry;

653 a| Analytical Chemistry;

653 a| Polymer Chemistry;

700 1 a| Romack, Timothy J.=| ^A1035328;

710 2 a| East Carolina University.b| Department of Chemistry.?| UNAUTHORIZED;

856 40 z| Access via ScholarShipu| http://hdl.handle.net/10342/3664;

949 o| jgml;

994 a| C0b| ERE;

596 a| 1 4;

998 a| 2533161;

999 a| CLICK ON WEB ADDRESSw| ASISc| 1i| 2533161-1001l| JNETm| JOYNERr| Ys| Yt| JNE3ETDu| 8/26/2011x| ETDz| JERESOURCE;

999 a| CLICK ON WEB ADDRESSw| ASISc| 1i| 2533161-2001l| HSLELECm| HSLr| Ys| Yt| HEETDu| 8/26/2011x| ETDz| HERESOURCE;

Electrospray ionization time of flight mass spectrometry of poly(methyl methacrylate) and polystyrene using surface active quaternary ammonium salts / by Christopher M. Williams.

Author/creator	Williams, Christopher M.
Other author	Romack, Timothy J.
Other author	East Carolina University. Department of Chemistry.
Format	Theses and dissertations
Publication Info	[Greenville, N.C.] : East Carolina University, 2011.
Description	83 pages : illustrations (some color), digital, PDF file
Supplemental Content	Access via ScholarShip
Subjects	Electrospray ionization mass spectrometry. Mass spectrometry. Time-of-flight mass spectrometry. Polymethylmethacrylate. Polystyrene. Polymers. Quaternary ammonium salts. Surface active agents.

Summary	Electrospray ionization time of flight mass spectrometry (ESI-ToF-MS) is a powerful characterization technique for large nonvolatile compounds, but has found limited applicability in the synthetic polymer field. Two factors currently limit the utility of ESI-ToF-MS for synthetic polymer characterization: 1) Electrospray ionization often results in multiply charged species for each component in the sample. Synthetic polymers contain a distribution of many compounds with close, uniformly spaced masses. The presence of multiple m/z peaks for each mass typically results in data that is complicated and becomes increasingly complicated as the average molar mass of the sample increases. 2) Electrospray ionization is best suited for polar, easily ionized species dissolved in polar solvents. The vast majority of synthetic polymers are relatively non-polar, do not ionize easily and are not soluble in the polar solvents most often used for ESI. By adding easily ionizable, surface active quaternary ammonium salts that associate with polymer molecules during ionization, we have made significant strides in overcoming both of these limitations. By using cetyltrimethylammonium bromide (CTAB) as an additive, we have been able to produce ESI-MS spectra with only singly charged charge states for the entire m/z range observable by our instrument (m/z = 0 - 20,000). Data will be presented for poly(methyl methacrylate) and polystyrene samples. Weight averaged molecular weight (Mw), number averaged molecular weight (Mn) and polydispersity (PD) calculations were all in good agreement with comparative analysis using Gel Permeation Chromatography (GPC) and Gel Permeation Chromatography - Multi-Angle Light Scattering (GPC-MALS). Further, for some samples, multiple distributions were identified corresponding to different end groups highlighting the utility of this approach.
General note	Presented to the faculty of the Department of Chemistry.
General note	Advisor: Timothy Romack.
General note	Title from PDF t.p. (viewed Oct. 20, 2011).
Dissertation note	M.A. East Carolina University 2011.
Bibliography note	Includes bibliographical references.
Technical details	System requirements: Adobe Reader.
Technical details	Mode of access: World Wide Web.

Availability

Library	Location	Call Number	Status	Item Actions
	Electronic Resources	Access Content Online	✔ Available

Electrospray ionization time of flight mass spectrometry of poly(methyl methacrylate) and polystyrene using surface active quaternary ammonium salts / by Christopher M. Williams.

Click here for more information about this title

Availability