@article{sezaki_hubbe_heitmann_argyropoulos_wang_2006, title={Colloidal effects of acrylamide polyampholytes - Part 1. Electrokinetic behavior}, volume={281}, ISSN={["1873-4359"]}, DOI={10.1016/j.colsurfa.2006.02.019}, abstractNote={The colloidal and electrokinetic behavior of three amphoteric acrylamide-based water-soluble terpolymers of high molecular mass was elucidated in terms of their structure and composition, using potentiometric and colloidal titrations, as well as microelectrophoresis, viscometry, and turbidity measurements. Independent variables included polymer composition, pH, and the concentration of salt ions. The electrokinetic properties, titratable charge, and isoelectric pH values of the samples were compared to their monomeric composition, as confirmed by NMR and FTIR analysis. The electrophoretic mobilities of the polyampholytes changed relatively rapidly with pH in the neighborhood of the isoelectric pH values, consistent with an enrichment of excess charges toward the outer parts of the macromolecules. Interactions of the polyampholytes with highly-charged titrants appeared to be less pH-dependent, in the neighborhood of the isoelectric condition, relative to a linear prediction based on the numbers of acidic and basic macromolecular groups. Specific viscosity measurements, in the vicinity of the isoelectric point, were found to increase with increasing salt concentration, which is a typical anti-polyelectrolyte behavior. In a similar manner, salt addition suppressed the development of a turbidity maximum at the isoelectric point.}, number={1-3}, journal={COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS}, author={Sezaki, Takao and Hubbe, Martin A. and Heitmann, John A. and Argyropoulos, Dimitris S. and Wang, Xingwu}, year={2006}, month={Jun}, pages={74–81} }
 @article{rusa_rusa_peet_uyar_fox_hunt_wang_balik_tonelli_2006, title={The nano-threading of polymers}, volume={55}, ISSN={["1573-1111"]}, DOI={10.1007/s10847-005-9038-1}, number={1-2}, journal={JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY}, author={Rusa, C. C. and Rusa, M. and Peet, J. and Uyar, T. and Fox, J. and Hunt, M. A. and Wang, X. and Balik, C. M. and Tonelli, A. E.}, year={2006}, month={Jun}, pages={185–192} }
 @article{wang_rusa_hunt_tonelli_macko_pasch_2005, title={Adsorption of polyethylene and polypropylene by zeolites: Inside or outside?}, volume={38}, ISSN={["1520-5835"]}, DOI={10.1021/MA051748a}, abstractNote={ADVERTISEMENT RETURN TO ISSUECommunication to the...Communication to the EditorNEXTAdsorption of Polyethylene and Polypropylene by Zeolites: Inside or Outside?Xingwu Wang, Cristian C. Rusa, Marcus A. Hunt, Alan E. Tonelli, Tibor Macko, and Harald PaschView Author Information Fiber & Polymer Science Program, North Carolina State University, Campus Box 8301, Raleigh, North Carolina 27695-8301, and German Institute for Polymers, Schlossgartenstr. 6, D-64289, Darmstadt, Germany Cite this: Macromolecules 2005, 38, 25, 10341–10345Publication Date (Web):November 8, 2005Publication History Received5 August 2005Revised25 October 2005Published online8 November 2005Published inissue 1 December 2005https://doi.org/10.1021/ma051748aCopyright © 2005 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views412Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (125 KB) Get e-AlertsSUBJECTS:Chromatography,Differential scanning calorimetry,Polyethylene,Polymers,Zeolites Get e-Alerts}, number={25}, journal={MACROMOLECULES}, author={Wang, XW and Rusa, CC and Hunt, MA and Tonelli, AE and Macko, T and Pasch, H}, year={2005}, month={Dec}, pages={10341–10345} }
 @article{porbeni_shin_shuai_wang_white_jia_tonelli_2005, title={Morphology and dynamics of the poly(epsilon-caprolactone)-b-poly(L-lactide) diblock copolymer and its inclusion compound with alpha-cyclodextrin: A solid-state C-13 NMR study}, volume={43}, ISSN={["1099-0488"]}, DOI={10.1002/polb.20490}, abstractNote={A biodegradable diblock copolymer of poly(e-caprolactone) (PCL) and poly (L-lactide) (PLLA) was synthesized and characterized. The inclusion compound (IC) of this copolymer with α-cyclodextrin (α-CD) was formed and characterized. Wide-angle X-ray diffraction showed that in the IC crystals o-CDs were packed in the channel mode, which isolated and restricted the individual guest copolymer chains to highly extended conformation. Solid-state 13 C NMR techniques were used to investigate the morphology and dynamics of both the bulk and α-CD-IC isolated PCL-b-PLLA chains. The conformation of the PCL blocks isolated within the o-CD cavities was similar to the crystalline conformation of PCL blocks in the bulk copolymer. Spin-lattice relaxation time (T 1 C) measurements revealed a dramatic difference in the mobilities of the semicrystalline bulk copolymer chains and those isolated in the α-CD-IC channels. Carbon-observed proton spin-lattice relaxation in the rotating frame measurements (T 1ρ H) showed that the bulk copolymer was phase-separated, while, in the IC, exchange of proton magnetization through spin-diffusion between the isolated guest polymer chains and the host α-CD was not complete. The two-dimensional solid-state heteronuclear correlation (HetCor) method was also employed to monitor proton communication in these samples. Intrablock exchange of proton magnetization was observed in both the bulk semicrystalline and IC copolymer samples at short mixing times; however, even at the longest mixing time, interblock proton communication was not observed in either sample. In spite of the physical closeness between the isolated included guest chains and the host α-CD molecules, efficient proton spin diffusion was not observed between them in the IC.}, number={15}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Porbeni, FE and Shin, ID and Shuai, XT and Wang, XW and White, JL and Jia, X and Tonelli, AE}, year={2005}, month={Aug}, pages={2086–2096} }
 @article{uyar_el-shafei_wang_hacaloglu_tonelli_2005, title={The Solid Channel Structure Inclusion Complex Formed Between Guest Styrene and Host γ-Cyclodextrin}, volume={55}, ISSN={0923-0750 1573-1111}, url={http://dx.doi.org/10.1007/s10847-005-9026-5}, DOI={10.1007/s10847-005-9026-5}, number={1-2}, journal={Journal of Inclusion Phenomena and Macrocyclic Chemistry}, publisher={Springer Science and Business Media LLC}, author={Uyar, Tamer and El-Shafei, Ahmed and Wang, Xingwu and Hacaloglu, Jale and Tonelli, Alan E.}, year={2005}, month={Dec}, pages={109–121} }
 @article{jia_wang_tonelli_white_2005, title={Two-dimensional spin-diffusion NMR reveals differential mixing in biodegradable polymer blends}, volume={38}, ISSN={["1520-5835"]}, DOI={10.1021/ma047838h}, abstractNote={Length scales of mixing in amorphous blends of solid PCL (polycaprolactone) and PLLA (poly-l-lactic acid) were investigated as a function of preparation method. A recently described two-dimensional heteronuclear correlation (Hetcor) spin-diffusion technique (Jia et al. Macromolecules 2003, 36, 712) revealed that PCL/PLLA blends with shorter length scales of mixing, relative to solution blending, could be prepared using inclusion-compound coalescence methods (Rusa et al. Macromolecules 2000, 33, 5321). These biocompatible and biodegradable polymer blends provide a clear example of the utility of the 2D Hetcor spin-diffusion method for quantitative miscibility and phase analysis in amorphous macromolecules and their blends. The rates for intrapolymer polarization transfer vs interchain/interdomain polarization equilibration were easily differentiated using the 2D technique for either blend. As a result, spin-diffusion coefficients and miscibility length scales could be calculated by direct measurement on th...}, number={7}, journal={MACROMOLECULES}, author={Jia, X and Wang, XW and Tonelli, AE and White, JL}, year={2005}, month={Apr}, pages={2775–2780} }
 @article{rusa_uyar_rusa_hunt_wang_tonelli_2004, title={An intimate polycarbonate/poly(methyl methacrylate)/poly(vinyl acetate) ternary blend via coalescence from their common inclusion compound with gamma-cyclodextrin}, volume={42}, ISSN={["1099-0488"]}, DOI={10.1002/polb.20273}, abstractNote={In this study, we successfully report an intimate ternary blend system of polycarbonate (PC)/poly(methyl methacrylate) (PMMA)/poly(vinyl acetate) (PVAc) obtained by the simultaneous coalescence of the three guest polymers from their common γ-cyclodextrin (γ-CD) inclusion compound (IC). The thermal transitions and the homogeneity of the coalesced ternary blend were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The observation of a single, common glass transition strongly suggests the presence of a homogeneous amorphous phase in the coalesced ternary polymer blend. This was further substantiated by solid-state 13 C NMR observation of the T 1ρ ( 1 H)s for each of the blend components. For comparison, ternary blends of PC/PMMA/PVAc were also prepared by traditional coprecipitation and solution casting methods. TGA data showed a thermal stability for the coalesced ternary blend that was improved over the coprecipitated blend, which was phase-segregated. The presence of possible interactions between the three polymer components was investigated by infrared spectroscopy (FTIR). The analysis indicates that the ternary blend of these polymers achieved by coalescence from their common γ-CD-IC results in a homogeneous polymer blend, possibly with improved properties, whereas coprecipitation and solution cast methods produced phase separated polymer blends. It was also found that control of the component polymer molar ratios plays a key role in the miscibility of their coalesced ternary blends. Coalescence of two or more normally immiscible polymers from their common CD-ICs appears to be a general method for obtaining well-mixed, intimate blends.}, number={22}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Rusa, CC and Uyar, T and Rusa, M and Hunt, MA and Wang, XW and Tonelli, AE}, year={2004}, month={Nov}, pages={4182–4194} }
 @article{rusa_wang_tonelli_2004, title={Fabrication of inclusion compounds with solid host gamma-cyclodextrins and water-soluble guest polymers: Inclusion of poly(N-acylethylenimine)s in gamma-cyclodextrin channels as monitored by solution H-1 NMR}, volume={37}, ISSN={["1520-5835"]}, DOI={10.1021/ma040081+}, abstractNote={We successfully report the formation of poly(N-acylethylenimine)−γ-cyclodextrin inclusion compounds (PNAI-γ-CD ICs). The PNAI-γ-CD ICs were obtained by three techniques:  (a) the precipitation of γ-CD in the polymer solution and (b) and (c) the suspension of as-received cage structure γ-CD and γ-CDCS, with a preformed channel structure, respectively, in the polymer solutions. The PNAI-γ-CD ICs were characterized by solid-state FTIR, X-ray, NMR, DSC, and TGA observations. A 1H NMR study was performed in order to follow the kinetics of the inclusion process in solution. The time-dependent inclusion of PNAIs with different molecular weights by suspension of either as-received cage structure γ-CD or channel structure γ-CDCS in the PNAI solutions was monitored with 1H NMR. Acetone, a nonsolvent for γ-CD, was used as the solvent for the PNAI solutions. Some aspects regarding the role water plays in the polymer inclusion process are revealed from our temporal observations of the inclusion of PNAI guests into sol...}, number={18}, journal={MACROMOLECULES}, author={Rusa, M and Wang, XW and Tonelli, AE}, year={2004}, month={Sep}, pages={6898–6903} }
 @article{jia_wolak_wang_white_2003, title={Independent calibration of H-1 spin-diffusion coefficients in amorphous polymers by intramolecular polarization transfer}, volume={36}, ISSN={["0024-9297"]}, DOI={10.1021/ma0215316}, abstractNote={We report a general method, based on intramolecular spin diffusion, for the measurement and calculation of spin-diffusion coefficients in amorphous polymers and their blends using only NMR data. The basic structural unit that defines 1H polarization density in polymers is the monomer unit. Using appropriately selected internal reference distances calculated from energy-minimized chain dimension simulations, time scales for the redistribution of 1H polarization within amorphous homopolymers may be used to independently calculate maximum values of the spin-diffusion coefficients D. This strategy represents an attractive alternative to current methods employed for domain size measurements in polymer blends, which require calibration of spin-diffusion coefficients based on comparisons of similar NMR data obtained on model compounds analyzed previously using scattering or microscopy techniques. In this way, many more polymer systems become amenable to study by NMR spin-diffusion methods, since X-ray scattering...}, number={3}, journal={MACROMOLECULES}, author={Jia, X and Wolak, J and Wang, XW and White, JL}, year={2003}, month={Feb}, pages={712–718} }
 @article{rusa_bullions_fox_porbeni_wang_tonelli_2002, title={Inclusion compound formation with a new columnar cyclodextrin host}, volume={18}, ISSN={["0743-7463"]}, DOI={10.1021/la0262452}, abstractNote={α- and γ-cyclodextrin in columnar structures with only water molecules included were successfully obtained by appropriate recrystallization from their aqueous solutions. These crystals were found to adopt a channel-type structure similar to the cyclodextrin inclusion compounds formed with guest polymers. Experimental investigations of their inclusion properties demonstrate that only α-cyclodextrin in the columnar structure (α-CDcs) is able to include both small molecules and polymers. Thermal measurements reveal that columnar structure α-CDcs contains three different types of water molecules. The most strongly held water molecules are located outside of the cyclodextrin cavity, likely hydrogen-bonded between the rims of neighboring cyclodextrins in the columnar α-CD stacks. X-ray analyses confirm that the channel structure is preserved in the dehydrated α-CDcs and its inclusion compounds formed with various guests. In contrast, a completely different behavior was observed for γ-CDcs in the columnar struct...}, number={25}, journal={LANGMUIR}, author={Rusa, CC and Bullions, TA and Fox, J and Porbeni, FE and Wang, XW and Tonelli, AE}, year={2002}, month={Dec}, pages={10016–10023} }
 @misc{wang_white_2002, title={Intramonomer polarization transfer: Calibrating spin diffusion coefficients in mobile polyolefins and their blends}, volume={35}, number={10}, journal={Macromolecules}, author={Wang, X. W. and White, J. L.}, year={2002}, pages={3795–3798} }
 @article{wei_davis_urban_song_porbeni_wang_white_balik_rusa_fox_et al._2002, title={Manipulation of nylon-6 crystal structures with its alpha-cyclodextrin inclusion complex}, volume={35}, ISSN={["0024-9297"]}, DOI={10.1021/ma020765m}, abstractNote={We successfully formed an inclusion complex between nylon-6 and α-cyclodextrin and attempted to use the formation and subsequent disassociation of the nylon-6/α-cyclodextrin inclusion complex to manipulate the polymorphic crystal structures, crystallinity, and orientation of nylon-6. Formation of the inclusion complex was verified by Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and CP/MAS 13C NMR. After obtaining the inclusion complex of nylon-6 and α-cyclodextrin, the sample was treated in an acid environment to remove the host α-cyclodextrin and coalesce the nylon-6 guest polymer. Examination of as-received and IC coalesced nylon-6 samples showed that the α-form crystalline phase of nylon-6 is the dominant component in the coalesced sample. X-ray diffraction patterns demonstrate that the γ-form is significantly suppressed in the coalesced sample. Along with the change in crystal form, an increase in crystallinity of ∼80% wa...}, number={21}, journal={MACROMOLECULES}, author={Wei, M and Davis, W and Urban, B and Song, YQ and Porbeni, FE and Wang, XW and White, JL and Balik, CM and Rusa, CC and Fox, J and et al.}, year={2002}, month={Oct}, pages={8039–8044} }
 @article{wang_coleman_jia_white_2002, title={Quantitative investigations of acidity, and transient acidity, in zeolites and molecular sieves}, volume={106}, number={19}, journal={Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces & Biophysical}, author={Wang, X. W. and Coleman, J. and Jia, X. and White, J. L.}, year={2002}, pages={4941–4946} }
 @article{white_wang_2002, title={Structural investigations of solid proteins at natural abundance using 2D multiple-pulse NMR}, volume={35}, ISSN={["0024-9297"]}, DOI={10.1021/ma012067s}, abstractNote={Results from multiple-pulse 2D 1H−13C correlation experiments are described for natural proteins in the solid state. Detailed HETCOR experiments on the complex silk fibroin proteins Samia cynthia ricini (S. c. ricini) and Bombyx mori (B. mori) demonstrate that while the expected dipolar-mediated 13C and 1H correlations are observed, additional chemical shift and coupling information involving amide linkages and dilute peptides are also detected indirectly. This is an important result since we show that the 1H chemical shifts for −NH groups in S. c. ricini are not resolved in the CRAMPS experiments, thereby preventing their direct measurement. Chemical shifts via dipolar couplings (two-spin and multiple-spin interactions) are also detected for dilute peptides in the silk fibroins, again providing key structure information for these functional residues that is completely absent in the CRAMPS data. Relative dynamics of bulky side groups from dilute amino acid residues are apparent from the 2D multiple-pulse ...}, number={7}, journal={MACROMOLECULES}, author={White, JL and Wang, XW}, year={2002}, month={Mar}, pages={2633–2639} }