Matches in SemOpenAlex for { <https://semopenalex.org/work/W2951921767> ?p ?o ?g. }
Showing items 1 to 73 of
73
with 100 items per page.
- W2951921767 abstract "Gas phase and cluster experiments provide unique opportunities to quantitatively study the effects of initiators, solvents, chain transfer agents, and inhibitors on the mechanisms of polymerization. Furthermore, a number of important phenomena, unique structures, and novel properties may exist during gas-phase and cluster polymerization. In this regime, the structure of the growing polymer may change dramatically and the rate coefficient may vary significantly upon the addition of a single molecule of the monomer. These changes would be reflected in the properties of the oligomers deposited from the gas phase. At low pressures, cationic and radical cationic polymerizations may proceed in the gas phase through elimination reactions. In the same systems at high pressure, however, the ionic intermediates may be stabilized, and addition without elimination may occur. In isolated van der Waals clusters of monomer molecules, sequential polymerization with several condensation steps can occur on a time scale of a few microseconds following the ionization of the gas-phase cluster. The cluster reactions, which bridge gas-phase and condensed-phase chemistry, allow examination of the effects of controlled states of aggregation. This Account describes several examples of gas-phase and cluster polymerization studies where the most significant results can be summarized as follows: (1) The carbocation polymerization of isobutene shows slower rates with increasing polymerization steps resulting from entropy barriers, which could explain the need for low temperatures for the efficient propagation of high molecular weight polymers. (2) Radical cation polymerization of propene can be initiated by partial charge transfer from an ionized aromatic molecule such as benzene coupled with covalent condensation of the associated propene molecules. This novel mechanism leads exclusively to the formation of propene oligomer ions and avoids other competitive products. (3) Structural information on the oligomers formed by gas-phase polymerization can be obtained using the mass-selected ion mobility technique where the measured collision cross-sections of the selected oligomer ions and collision-induced dissociation can provide fairly accurate structural identifications. The identification of the structures of the dimers and trimers formed in the gas-phase thermal polymerization of styrene confirms that the polymerization proceeds according to the Mayo mechanism. Similarly, the ion mobility technique has been utilized to confirm the formation of benzene cations by intracluster polymerization following the ionization of acetylene clusters. Finally, it has been shown that polymerization of styrene vapor on the surface of activated nanoparticles can lead to the incorporation of a variety of metal and metal oxide nanoparticles within polystyrene films. The ability to probe the reactivity and structure of the small growing oligomers in the gas phase can provide fundamental insight into mechanisms of polymerization that are difficult to obtain from condensed-phase studies. These experiments are also important for understanding the growth mechanisms of complex organics in flames, combustion processes, interstellar clouds, and solar nebula where gas-phase reactions, cluster polymerization, and surface catalysis on dust nanoparticles represent the major synthetic pathways. This research can lead to the discovery of novel initiation mechanisms and reaction pathways with applications in the synthesis of oligomers and nanocomposites with unique and improved properties." @default.
- W2951921767 created "2019-06-27" @default.
- W2951921767 creator A5068222384 @default.
- W2951921767 date "2008-10-07" @default.
- W2951921767 modified "2023-09-26" @default.
- W2951921767 title "ChemInform Abstract: Polymerization in the Gas Phase, in Clusters, and on Nanoparticle Surfaces" @default.
- W2951921767 cites W2023578872 @default.
- W2951921767 doi "https://doi.org/10.1002/chin.200841280" @default.
- W2951921767 hasPublicationYear "2008" @default.
- W2951921767 type Work @default.
- W2951921767 sameAs 2951921767 @default.
- W2951921767 citedByCount "0" @default.
- W2951921767 crossrefType "journal-article" @default.
- W2951921767 hasAuthorship W2951921767A5068222384 @default.
- W2951921767 hasConcept C111998727 @default.
- W2951921767 hasConcept C121120078 @default.
- W2951921767 hasConcept C159467904 @default.
- W2951921767 hasConcept C166940927 @default.
- W2951921767 hasConcept C167076587 @default.
- W2951921767 hasConcept C16728422 @default.
- W2951921767 hasConcept C178790620 @default.
- W2951921767 hasConcept C183882617 @default.
- W2951921767 hasConcept C185592680 @default.
- W2951921767 hasConcept C188027245 @default.
- W2951921767 hasConcept C32909587 @default.
- W2951921767 hasConcept C44228677 @default.
- W2951921767 hasConcept C44710219 @default.
- W2951921767 hasConcept C521977710 @default.
- W2951921767 hasConcept C75473681 @default.
- W2951921767 hasConcept C84687054 @default.
- W2951921767 hasConceptScore W2951921767C111998727 @default.
- W2951921767 hasConceptScore W2951921767C121120078 @default.
- W2951921767 hasConceptScore W2951921767C159467904 @default.
- W2951921767 hasConceptScore W2951921767C166940927 @default.
- W2951921767 hasConceptScore W2951921767C167076587 @default.
- W2951921767 hasConceptScore W2951921767C16728422 @default.
- W2951921767 hasConceptScore W2951921767C178790620 @default.
- W2951921767 hasConceptScore W2951921767C183882617 @default.
- W2951921767 hasConceptScore W2951921767C185592680 @default.
- W2951921767 hasConceptScore W2951921767C188027245 @default.
- W2951921767 hasConceptScore W2951921767C32909587 @default.
- W2951921767 hasConceptScore W2951921767C44228677 @default.
- W2951921767 hasConceptScore W2951921767C44710219 @default.
- W2951921767 hasConceptScore W2951921767C521977710 @default.
- W2951921767 hasConceptScore W2951921767C75473681 @default.
- W2951921767 hasConceptScore W2951921767C84687054 @default.
- W2951921767 hasLocation W29519217671 @default.
- W2951921767 hasOpenAccess W2951921767 @default.
- W2951921767 hasPrimaryLocation W29519217671 @default.
- W2951921767 hasRelatedWork W1499107805 @default.
- W2951921767 hasRelatedWork W1602747576 @default.
- W2951921767 hasRelatedWork W2020632977 @default.
- W2951921767 hasRelatedWork W2023578872 @default.
- W2951921767 hasRelatedWork W2024000080 @default.
- W2951921767 hasRelatedWork W2057275026 @default.
- W2951921767 hasRelatedWork W2064537246 @default.
- W2951921767 hasRelatedWork W2072256411 @default.
- W2951921767 hasRelatedWork W2089311794 @default.
- W2951921767 hasRelatedWork W2110542418 @default.
- W2951921767 hasRelatedWork W2118603273 @default.
- W2951921767 hasRelatedWork W2124677481 @default.
- W2951921767 hasRelatedWork W2611544400 @default.
- W2951921767 hasRelatedWork W2902791680 @default.
- W2951921767 hasRelatedWork W3010373989 @default.
- W2951921767 hasRelatedWork W3023727444 @default.
- W2951921767 hasRelatedWork W34431502 @default.
- W2951921767 hasRelatedWork W616585817 @default.
- W2951921767 hasRelatedWork W932907120 @default.
- W2951921767 hasRelatedWork W1972198297 @default.
- W2951921767 isParatext "false" @default.
- W2951921767 isRetracted "false" @default.
- W2951921767 magId "2951921767" @default.
- W2951921767 workType "article" @default.