Author: Madalis Casiano-Maldonado
Publisher:
ISBN:
Category : Biodegradation
Languages : en
Pages : 178
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Book Description
The characterization of synthetic polymers and complex oligomeric mixtures by a combination of different mass spectrometry (MS) techniques is the main topic of this dissertation. Ion mobility (IM) separation and/or tandem mass spectrometry (MS2) were interfaced with single stage mass spectrometry for the fast, complete, precise and accurate characterization of different polymers, biopolymers, and biodegradation products. Additionally, the development of a mass spectrometry protocol for the quantitation of proteins adsorbed on different polymer surfaces was accomplished in this dissertation. Over the passed years, synthetic routes for the creation of PEGs have been modified by the elimination of organic catalysts and solvents and the application of green chemistry for the generation of new polymers. In Chapter 4 of this dissertation, MS and MS2 were employed, as the main analytical techniques, for the structural elucidation of enzyme-catalyzed, functionalized PEG and tetraethylene glycol (TEG) biomaterials. The samples analyzed were synthesized by two different processes, transesterification and Michael addition reactions, both of them using CALB as the catalyst. In Chapter 5 of this dissertation, polylactide was degraded using Proteinase K and its biodegradation products were analyzed by MS and MS2. Elucidation of its degradation products is important to the biomedical community; knowledge of these products helps to see any toxicity problems with the use of this polymer. The MS and MS2 results showed that the degradation products are short polylactide chains, down to the monomer. No other, potentially dangerous organics were detected. In the following chapter of this dissertation (Chapter 6), the adsorption of three model proteins onto two different surfaces was evaluated over a pH range. The results were explained on terms of polymer chemistry, surface morphology, proteins' isoelectricpoints and molecular dimensions. Finally, Chapter 7 reports how derivatization, degradation, or chromatographic separation can be avoided for the analysis of complex systems, if multidimensional mass spectrometry methods combining ion mobility separation and different ionization techniques are employed. Using this new approach complex poly([alpha]-peptoid) samples were characterized. The results showed that the main product in the system contained the N-heterocyclic carbene (NHC) moiety that served as ring-opening polymerization catalyst. Furthermore, it was demonstrated that elimination of the NHC segment leads to cyclic poly([alpha]-peptoid)s that have very similar conformations with comparably sized polypeptides.
Author: Minna Hakkarainen
Publisher: Springer Science & Business Media
ISBN: 3642280412
Category : Technology & Engineering
Languages : en
Pages : 219
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Book Description
Emerging Mass Spectrometric Tools for Analysis of Polymers and Polymer Additives, by Nina Aminlashgari and Minna Hakkarainen. Analysis of Polymer Additives and Impurities by Liquid Chromatography/Mass Spectrometry and Capillary Electrophoresis/Mass Spectrometry, by Wolfgang Buchberger and Martin Stiftinger. Direct Insertion Probe Mass Spectrometry of Polymers, by Jale Hacaloglu Mass Spectrometric Characterization of Oligo- and Polysaccharides and Their Derivatives, by Petra Mischnick. Electrospray Ionization-Mass Spectrometry for Molecular Level Understanding of Polymer Degradation, by Minna Hakkarainen.
Author: Liang Li
Publisher: John Wiley & Sons
ISBN: 0470567228
Category : Science
Languages : en
Pages : 325
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Book Description
Principles and Practices of Polymer Mass Spectrometry helps readers acquire the skills necessary for selecting the optimal methods, handling samples, analyzing the data, and interpreting the results of the mass spectrometry of polymers. This guide describes the principles of polymer MS and best practices in polymer characterization. It discusses different approaches, including MALDI, ESI, TOF MS, and FT-MS. It provides a guide to developing appropriate sample preparation protocols for different polymers. Complete with examples of applications and experiments, this is an excellent reference for scientists, researchers, graduate students, and others.
Author: Harald Pasch
Publisher: Springer Science & Business Media
ISBN: 3662050463
Category : Science
Languages : en
Pages : 312
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Book Description
MALDI-TOF mass spectrometry is one of the latest and most fascinating new developments in the analysis of organic compounds. Originally developed for the analysis of biomolecules, it has developed into one of the most powerful techniques for the characterization of synthetic polymers. This book describes the fundamentals of the MALDI process and the technical features of MALDI-TOF instrumentation. It reviews the application of MALDI-TOF for identification, chemical and molar mass analysis of synthetic polymers. With many examples, the monograph examines experimental protocols for the determination of endgroups, the analysis of copolymers and additives, and the coupling of liquid chromatography and MALDI-TOF in detail.
Author: Nadrah Alawani
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 238
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Book Description
This dissertation focuses on coupling mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to thermal degradation, liquid chromatography (LC) and/or ion mobility (IM) spectrometry for the characterization of complex mixtures. In chapter II, an introduction of the history and the principles of mass spectrometry (MS) and liquid chromatography (LC) are discussed. Chapter III illustrates the materials and instrumentation used to complete this dissertation. Polyethers have been characterized utilizing tandem mass spectrometry (MS/MS), as presented in Chapter IV and Chapter VI. Diblock copolymers of polyethylene oxide and polycaprolactone, PEO-b-PCL, have been characterized by matrix-assisted laser desorption/ionization quadrupole/time-of-flight mass spectrometry (MALDI-Q/ToF) and LC-MS/MS (Chapter V). Thermoplastic elastomers have been characterized by thermal degradation using an atmospheric solids analysis probe (ASAP) and ion mobility mass spectrometry (IM-MS), as discussed in Chapter VII. Interfacing separation techniques with mass spectrometry permitted the detection of species present with low concentration in complex materials and improved the sensitivity of MS. In chapter IV, the fragmentation mechanisms in MS/MS experiments of cyclic and linear poly(ethylene oxide) macroinitiators are discussed. This study aimed at determining the influence of end groups on the fragmentation pathways. In the study reported in Chapter V, ultra high performance liquid chromatography (UHPLC) was interfaced with MS and MS/MS to achieve the separation and in-depth characterization and separation of amphiphilic diblock copolymers (PEO-b-PCL) in which the architecture of the PEO block is linear or cyclic. Applying UPLC-MS and UPLC-MS/MS provides fast accurate information about the number and type of the blocks in the copolymers. Chapter VI reports MS/MS and IM-MS analyses which were performed to elucidate the influence of molecular size and collision energy on the fragmentation pathways of polyethers subjected to collisionally activated dissociation (CAD). Survival yields and collision cross-sections were derived for several oligomers of polybutylene oxide (PBO) and polytetrahydrofuran (PTHF) polymers by MS/MS and IM-MS, in order to understand their fragmentation energetics and fully characterize their structures. In Chapter VII, application of atmospheric solids analysis probe (ASAP) and ion mobility (IM) separation were coupled with mass spectrometry (MS) and tandem mass spectrometry (MS/MS) to characterize commercially available thermoplastic elastomers. These compounds are mainly composed of thermoplastic copolymers, but also contain additional chemicals to enhance their properties or to protect them from degradation. Using ASAP-IM-MS enables fast analysis, involving mild degradation at atmospheric pressure (ASAP) and subsequent characterization of the desorbates and pyrolyzates by ion mobility mass spectrometry (IM-MS) and tandem mass spectrometry (MS/MS). Such multidimensional dispersion considerably simplifies the resulting spectra, permitting the conclusive separation and characterization of the multicomponent materials examined. Chapter VIII summarizes the findings of this dissertation and is followed by appendices with supplemental data and the copyright permissions obtained for this dissertation.
Author: Kishor Kumar Sadasivuni
Publisher: Elsevier
ISBN: 0081009747
Category : Science
Languages : en
Pages : 546
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Book Description
Biopolymer Composites in Electronics examines the current state-of-the-art in the electronic application based on biopolymer composites. Covering the synthesis, dispersion of fillers, characterization and fabrication of the composite materials, the book will help materials scientists and engineers address the challenges posed by the increased use of biopolymeric materials in electronic applications. The influence of preparation techniques on the generation of micro, meso, and nanoscale fillers, and the effect of filler size and dispersion on various biopolymers are discussed in detail. Applications covered include sensors, actuators, optics, fuel cells, photovoltaics, dielectrics, electromagnetic shielding, piezoelectrics, flexible displays, and microwave absorbers. In addition, characterization techniques are discussed and compared, enabling scientists and engineers to make the correct choice of technique. This book is a ‘one-stop’ reference for researchers, covering the entire state-of-the-art in biopolymer electronics. Written by a collection of expert worldwide contributors from industry, academia, government, and private research institutions, it is an outstanding reference for researchers in the field of biopolymer composites for advanced technologies. Enables researchers to keep up with the rapid development of biopolymer electronics, which offer light, flexible, and more cost-effective alternatives to conventional materials of solar cells, light-emitting diodes, and transistors Includes thorough coverage of the physics and chemistry behind biopolymer composites, helping readers to become rapidly acquainted with the fiel Provides in-depth information on the range of biopolymer applications in electronics, from printed flexible conductors and novel semiconductor components, to intelligent labels, large area displays, and solar panels
Author: Liang Li
Publisher: Wiley
ISBN: 9780471775799
Category : Science
Languages : en
Pages : 307
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Book Description
Principles and Practices of Polymer Mass Spectrometry helps readers acquire the skills necessary for selecting the optimal methods, handling samples, analyzing the data, and interpreting the results of the mass spectrometry of polymers. This guide describes the principles of polymer MS and best practices in polymer characterization. It discusses different approaches, including MALDI, ESI, TOF MS, and FT-MS. It provides a guide to developing appropriate sample preparation protocols for different polymers. Complete with examples of applications and experiments, this is an excellent reference for scientists, researchers, graduate students, and others.
Author:
Publisher:
ISBN: 9789491407178
Category :
Languages : en
Pages : 157
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Book Description
"Polymers vary in terms of the monomer/s used; the number, distribution and type of linkage of monomers per molecule; and the side chains and end groups attached. Given this diversity, traditional single-technique approaches to characterization often give limited and inadequate information about a given polymer. Multi-technique but polymer-specific approach was found to be an appropriate alternative. This strategy was applied in characterizing polymers of a wide range of properties from simple polyethylene gylcol, to polycationic chitosan and aminopropyl based oligosiloxanes, and to polydiverse polyfluorinated polyethoxylates. Mass Spectrometry (MS) was used to characterize the different polymers. Different modes of sample introduction, ionization, mass analysis and detection were surveyed. The nature of the monomer units, the size and the polydispersity of polymers are the important factors that affect the detection and quantification of the polymer moieties using MS. MS gave information not just on the molecular weight but also about the repeating units of the polymers. Traditional techniques like size exclusion chromatography and infrared spectroscopy were also used to obtain complementary information on the properties of polymers. Chemometric techniques like partial least squares aided in the statistical evaluation of experimental data. The research works included in this thesis have demonstrated that polymer characterization can be accomplished with the use of a combination of different instrumental and statistical techniques. This strategy allows the researcher to explore additional information about the polymer formulation and correlate these to some observed behaviors or activities."--Samenvatting auteur.
Author: Vincenzo Scionti
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 165
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Book Description
This dissertation focuses on the application of new mass spectrometry approaches for the characterization of different types of synthetic materials. Combination of the classical and innovative methods, such as electron transfer dissociation (ETD) and ion mobility mass spectrometry (IM-MS) enabled the conclusive and unambiguous determination of macromolecular structures, end groups and architectures, as well as stoichiometry of high molecular weight complexes whose detection is often obscured by charge overlapping, viz. [M+Na]+ and [2M+2Na]2+. Chapter III concerns the investigation of phosphazenes, a broad class of important inorganic compounds. For this goal, different mass spectrometry techniques were employed to better understand the reaction products but also their particular chemistry under mass spectrometry conditions. The tadpole architecture was detected for the first time among the products of the reaction between NH4Cl and PCl5 by utilizing IM-MS and tandem mass spectrometry (MS2). The reaction [PCl2N]3 with MXn to form [PCl2N]3·HMXn+1 superacids was confirmed by detecting both the protonated weak base [PCl2N]3 and the corresponding labile anion species [MXn+1]−. Chapter IV evaluates of ETD, a new MS2 technique, for the structural analysis of polymers, specifically polyester homo- and copolymers, and also a comparison between this new method and the classical collisionally activated dissociation (CAD). Advantages of ETD over CAD, include less congested MS2 spectra due to site specific dissociations, fragment ions in a lower charge state than the precursor ion and absence the of consecutive dissociations of the first generation of fragment ions, which lead to more specific end group information and more readily interpretable spectra. The last chapter covers an investigation, by electrospray ionization mass spectrometry (ESI-MS), of the noncovalent interactions between differently substitued POSS molecules and sorbitol-type nucleating agents for developing nanocomposite materials with isotactic polypropylene (iPP). The complexes detected and their stoichiometries were confirmed not only by mass measurements but also by their dissociation (MS2) and by examination of their charge states and size by IM-MS. These studies confirmed the formation of high order heterocomplexes between POSS particles carrying both silanol and phenyl groups and sorbitol molecules substituted by phenyl groups, underscoring that both hydrogen bonding and pi - pi interactions are necessary to form POSS-sorbitol self-assemblies. Such self-assembled structures can be evenly blended with iPP to yield hybrid materials with superior physical and mechanical properties.
Author: Xiumin Liu
Publisher:
ISBN:
Category : Biomedical materials
Languages : en
Pages : 184
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Book Description
Tandem mass spectrometry (MS2) and ion mobility mass spectrometry (IM-MS) are powerful techniques to characterize biomaterials and polymers, and to provide structural information, on top of the compositional insight determined by single stage mass spectrometry (MS). In this study, collisionally activated dissociation (CAD) and electron transfer dissociation (ETD) were employed as MS2 fragmentation methods, and the resulting spectra were compared for specific compounds. The combination of MS2 with IM-MS was used for the characterization of protein conformation and the effect of polymers on protein conformational change. Chapter IV investigates the electron transfer dissociation (ETD) behavior of doubly charged ions with two different types of charges. Both CAD and ETD were used for the structural analysis of a protonated-sodiated peptide and sodiated-ammoniated polysaccharides. The advantages of ETD over CAD were documented with ETD spectra that showed more sequence-related fragment series for the peptide and revealed the location of the hydroxyethyl group on the pentamer of a polysaccharide. In Chapter V of this dissertation, the noncovalent interactions between proteins and polymers were investigated by electrospray ionization mass spectrometry (ESI-MS). Many synthetic polymers, when used for biomedical applications, come in contact with biological fluids. The polymers can significantly affect protein conformations in these fluids. The soft ionization feature of ESI enables the correlation between protein conformation and charge state distribution in the mass spectrum and the detection of protein-polymer complexes. ESI-MS data indicated that certain polysiloxanes can partially denature proteins. Chapter VI focuses on the precise structural characterization of branched glycopolymers. The two reactive sites on a mannose inimer, the polymerizable vinyl group and the homolytically cleavable halogen, enable the formation of hyperbranched architectures which are challenging to characterization. The presence of structural isomers in the sample was proposed based on the reaction mechanism of the synthesis. IM-MS and MS2 were employed as main analytical techniques in this study to unequirocally confirm the formation of branched structures.
