@article{paik_poliks_rusa_tonelli_schaefer_2007, title={Molecular motion of polycarbonate included in gamma-cyclodextrin}, volume={45}, ISSN={["0887-6266"]}, DOI={10.1002/polb.21112}, abstractNote={AbstractMolecular motions of single polycarbonate (PC) chains threaded into crystalline γ‐cyclodextrin (γ‐CD) channels were examined using solid‐state 13C NMR and molecular dynamics simulations. The location of PC within the channels was confirmed by spin diffusion from a PC 13C label to natural‐abundance 13C of the γ‐CD. Rotor‐encoded longitudinal magnetization (RELM) (under 7‐kHz magic‐angle sample‐spinning conditions) was combined with multiple‐pulse 1H‐1H dipolar decoupling to detect large‐amplitude phenyl‐ring motion in both bulk PC and polycarbonate γ‐cyclodextrin inclusion compound (PC‐γ‐CD). The RELM results indicate that the phenyl rings in PC‐γ‐CD undergo 180° flips faster than 10 kHz just as in bulk PC. The molecular dynamics simulations show that the frequency of the phenyl‐ring flips depends on the cooperative motions of PC atoms and neighboring atoms of the γ‐CD channel. The distribution of protonated aromatic‐carbon laboratory and rotating‐frame 13C spin‐lattice relaxation rates for bulk PC and PC‐γ‐CD are similar but not identical. The distributions for both systems arise from site heterogeneities. For bulk PC, the heterogeneity is attributed to variations in local chain packing, and for PC‐γ‐CD the heterogeneity arises from variations in the location of the PC phenyl rings in the γ‐CD channel. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1271–1282, 2007}, number={11}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Paik, Younkee and Poliks, Barbara and Rusa, Cristian C. and Tonelli, Alan E. and Schaefer, Jacob}, year={2007}, month={Jun}, pages={1271–1282} }
 @article{uyar_rusa_tonelli_hacaloglu_2007, title={Pyrolysis mass spectrometry analysis of polycarbonate/poly(methyl methacrylate)/poly(vinyl acetate) ternary blends}, volume={92}, ISSN={["1873-2321"]}, DOI={10.1016/j.polymdegradstab.2006.10.002}, abstractNote={Direct insertion probe pyrolysis mass spectrometry (DIP-MS) analyses of polycarbonate/poly(methyl methacrylate)/poly(vinyl acetate), (PC/PMMA/PVAc), ternary blends have been performed. The PC/PMMA/PVAc ternary blends were obtained by coalescing from their common γ-cyclodextrin–inclusion compounds (CD–ICs), through the removal of the γ-CD host (coalesced blend), and by a co-precipitation method (physical blend). The coalesced ternary blend showed different thermal behaviors compared to the co-precipitated physical blend. The stability of PC chains decreased due to the reactions of CH3COOH formed by deacetylation of PVAc above 300 °C, for both coalesced and physical blends. This process was more effective for the physical blend most likely due to the enhanced diffusion of CH3COOH into the amorphous PC domains, where it can further react producing low molecular weight PC fragments bearing methyl carbonate chain ends. The decrease in thermal stability of PC chains was less significant for the coalesced ternary blend indicating that the diffusion of CH3COOH was either somewhat limited or competed with intermolecular reactions between PMMA and PC and between PMMA and PVAc, which were detected and were associated with their close proximity in the intimately mixed coalesced PC/PMMA/PVAc ternary blend.}, number={1}, journal={POLYMER DEGRADATION AND STABILITY}, author={Uyar, Tamer and Rusa, Cristian C. and Tonelli, Alan E. and Hacaloglu, Jale}, year={2007}, month={Jan}, pages={32–43} }
 @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://pubs.acs.org/doi/10.1021/ma051748ahttps://doi.org/10.1021/ma051748arapid-communicationACS PublicationsCopyright © 2005 American Chemical SocietyRequest reuse permissionsArticle Views432Altmetric-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 InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS: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{rusa_bridges_ha_tonelli_2005, title={Conformational changes induced in Bombyx mori silk fibroin by cyclodextrin inclusion complexation}, volume={38}, ISSN={["1520-5835"]}, DOI={10.1021/ma050340a}, abstractNote={We have previously demonstrated that the formation of and coalescence from polymer−cyclodextrin (CD) inclusion compounds (ICs) represents a very useful approach to modify the chain conformations and improve the crystallinity of various bulk polymers. The present work deals, for the first time, with the formation of a γ-CD IC with a natural protein as guest, i.e., silk fibroin from Bombyx mori silkworm. Formation of the crystalline inclusion compound was verified by wide-angle X-ray diffraction, solid-state NMR, and infrared spectroscopy to have the host γ-CD molecules arranged in a channel structure, with the isolated silk chains included, at least in large part, in their internal cavities. Removing the γ-CD host lattice by washing with hot water produced a white coalesced silk sample that was collected and characterized. Unlike the original or precipitated silk fibroin, the coalesced sample shows most of its protein residues in a β-sheet conformation with an elevated degree of crystallinity.}, number={13}, journal={MACROMOLECULES}, author={Rusa, CC and Bridges, C and Ha, SW and Tonelli, AE}, year={2005}, month={Jun}, pages={5640–5646} }
 @article{uyar_rusa_wang_rusa_hacaloglu_tonelli_2005, title={Intimate blending of binary polymer systems from their common cyclodextrin inclusion compounds}, volume={43}, ISSN={["1099-0488"]}, DOI={10.1002/polb.20546}, abstractNote={AbstractA procedure for the formation of intimate blends of three binary polymer systems polycarbonate (PC)/poly(methyl methacrylate) (PMMA), PC/poly(vinyl acetate) (PVAc) and PMMA/PVAc is described. PC/PMMA, PC/PVAc, and PMMA/PVAc pairs were included in γ‐cyclodextrin (γ‐CD) channels and were then simultaneously coalesced from their common γ‐CD inclusion compounds (ICs) to obtain intimately mixed blends. The formation of ICs between polymer pairs and γ‐CD were confirmed by wide‐angle X‐ray diffraction (WAXD), fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). It was observed [solution 1H nuclear magnetic resonance (NMR)] that the ratios of polymers in coalesced PC/PMMA and PC/PVAc binary blends are significantly different than the starting ratios, and PC was found to be preferentially included in γ‐CD channels when compared with PMMA or PVAc. Physical mixtures of polymer pairs were also prepared by coprecipitation and solution casting methods for comparison. DSC, solid‐state 1H NMR, thermogravimetric analysis (TGA), and direct insertion probe pyrolysis mass spectrometry (DIP‐MS) data indicated that the PC/PMMA, PC/PVAc, and PMMA/PVAc binary polymer blends were homogeneously mixed when they were coalesced from their ICs. A single, common glass transition temperature (Tg) recorded by DSC heating scans strongly suggested the presence of a homogeneous amorphous phase in the coalesced binary polymer blends, which is retained after thermal cycling to 270 °C. The physical mixture samples showed two distinct Tgs and 1H T1ρ values for the polymer components, which indicated phase‐separated blends with domain sizes above 5 nm, while the coalesced blends exhibited uniform 1H spin‐lattice relaxation values, indicating intimate blending in the coalesced samples. The TGA results of coalesced and physical binary blends of PC/PMMA and PC/PVAc reveal that in the presence of PC, the thermal stability of both PMMA and PVAc increases. Yet, the presence of PMMA and PVAc decreases the thermal stability of PC itself. DIP‐MS observations suggested that the degradation mechanisms of the polymers changed in the coalesced blends, which was attributed to the presence of molecular interactions between the well‐mixed polymer components in the coalesced samples. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2578–2593, 2005}, number={18}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Uyar, T and Rusa, CC and Wang, XW and Rusa, M and Hacaloglu, J and Tonelli, AE}, year={2005}, month={Sep}, pages={2578–2593} }
 @article{rusa_wei_bullions_shuai_uyar_tonelli_2005, title={Nanostructuring polymers with cyclodextrins}, volume={16}, ISSN={["1099-1581"]}, DOI={10.1002/pat.566}, abstractNote={AbstractBulk solid polymer samples formed by the coalescence of guest polymer chains from their inclusion compounds (ICs) formed with host cyclodextrins (CDs) can result in significant reorganization of their phase structures, morphologies, and even chain conformations from those more commonly produced from randomly‐coiled, entangled polymer solutions and melts. When the cyclic host CDs are threaded by polymer chains to form crystalline polymer‐CD‐ICs, the guest polymers become highly extended due to the narrow host CD diameters (∼5, 7, and 9 Å for α‐, β‐, and γ‐CDs) and are segregated from neighboring guest polymer chains by the CD‐IC channel walls. As a consequence, when polymer‐CD‐IC crystals are treated with CD solvents that do not dissolve the guest polymers or are treated with amylase enzymes, the resulting coalesced bulk polymer samples often display properties distinct from those of normally produced bulk samples of the same polymers. In this article the CD‐IC processing of polymers to generate novel polymer microstructures and morphologies are described, to control the phase separation of immiscible blocks in block copolymers, and to form well‐mixed intimate blends of two or more polymers that are normally incompatible. The thermal and temporal stabilities of polymer samples coalesced from their ICs formed with CDs will also be mentioned, and it is suggested that the range of polymer properties can be greatly expanded by their CD‐IC processing. Copyright © 2005 John Wiley & Sons, Ltd.}, number={2-3}, journal={POLYMERS FOR ADVANCED TECHNOLOGIES}, author={Rusa, CC and Wei, M and Bullions, TA and Shuai, XT and Uyar, T and Tonelli, AE}, year={2005}, pages={269–275} }
 @article{uyar_rusa_hunt_aslan_hacaloglu_tonelli_2005, title={Reorganization and improvement of bulk polymers by processing with their cyclodextrin inclusion compounds}, volume={46}, ISSN={["1873-2291"]}, DOI={10.1016/j.polymer.2005.04.002}, abstractNote={The formation of polymer-cyclodextrin inclusion compounds of polycarbonate (PC), poly(methylmethacrylate) (PMMA) and poly(vinylacetate) (PVAc) guests with host γ-cyclodextrin (γ-CD) have been successfully achieved. Coalesced bulk polymer samples were obtained by removal of γ-CD from their inclusion compounds (ICs). The chemical and crystalline structures of ICs and coalesced PC, PMMA and PVAc were studied by Fourier transform infrared spectroscopy (FTIR) and wide-angle X-ray diffraction (WAXD). The thermal transitions, thermal stability, and degradation mechanisms of the samples were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and direct insertion probe pyrolysis mass spectrometry (DIP-MS). FTIR findings indicated that the chain conformations of the bulk polymers were altered when they were included inside the CD channels and extended chain conformations were retained when coalesced from their ICs. Significant improvements were observed in the thermal transitions observed for the coalesced polymers, with glass transitions shifted to higher temperatures. The TGA results reveal that the thermal stabilities of coalesced polymers increased slightly compared to the corresponding as-received polymers. The DIP-MS observations indicated that the thermal stability and degradation products of the polymers are affected once the polymers chains are included inside the γ-CD-IC cavities.}, number={13}, journal={POLYMER}, author={Uyar, T and Rusa, CC and Hunt, MA and Aslan, E and Hacaloglu, J and Tonelli, AE}, year={2005}, month={Jun}, pages={4762–4775} }
 @article{hunt_rusa_tonelli_balik_2005, title={Structure and stability of columnar cyclomaltooctaose (gamma-cyclodextrin) hydrate}, volume={340}, ISSN={["1873-426X"]}, DOI={10.1016/j.carres.2005.03.021}, abstractNote={Rapid recrystallization of cyclomaltooctaose (gamma-cyclodextrin, gamma-CD) from aqueous solution resulted in formation of a columnar structure with only water as the guest molecule. Upon vacuum drying at 90 degrees C for 15 h, gamma-CD, which was initially in the columnar structure, became amorphous. Complementary water vapor sorption and wide-angle X-ray diffractometry experiments were performed on columnar gamma-CD in its vacuum dried and as-precipitated states to elucidate its stability in humid environments and the crystal structure present at varying sorption levels. These experiments show that both types of gamma-CD transform to the cage crystal structure upon exposure to water vapor at 40 degrees C and with an activity of 1.0. Sorption equilibrium is reached long before the crystal structure transformation is complete, indicating that a significant amount of molecular mobility exists in the various hydrated gamma-CD crystal structures.}, number={9}, journal={CARBOHYDRATE RESEARCH}, author={Hunt, MA and Rusa, CC and Tonelli, AE and Balik, CM}, year={2005}, month={Jul}, pages={1631–1637} }
 @article{rusa_uyar_rusa_tonelli_2004, title={A miscible polycarbonate/poly(methyl methacrylate)/poly( vinyl acetate) ternary blend via coalescence from their common gamma-cyclodextrin inclusion compound}, volume={42}, journal={Journal of Polymer Science. Part B, Polymer Physics}, author={Rusa, C. C. and Uyar, T. and Rusa, M. and Tonelli, A. E.}, year={2004} }
 @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={AbstractIn 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 13C NMR observation of the T1ρ(1H)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. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4182–4194, 2004}, 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{hernandez_rusa_rusa_lopez_mijangos_tonelli_2004, title={Controlling PVA hydrogels with gamma-cyclodextrin}, volume={37}, ISSN={["0024-9297"]}, DOI={10.1021/ma048375i}, abstractNote={We report on the preparation and characterization of poly(vinyl alcohol) (PVA) hydrogels formed during freeze−thaw (F−T) cycles of their aqueous solutions containing γ-cyclodextrin (γ-CD). Crystalline inclusion compound (IC) formation was observed between PVA and γ-CD in these gels at low concentrations of γ-CD (γ-CD:PVA molar ratios < 1:25). Confirmation of the existence of the channel structure for γ-CD was achieved by characterizing the dried PVA/γ-CD hydrogels with solid-state DSC, TGA, WAXD, and 13C NMR. Some aspects regarding the mechanism and structure of PVA gels obtained via F−T cycles in the presence/absence of γ-CD are presented based on UV−vis, swelling, solution 1H NMR, and rheological observations. It was observed that the swelling and rheological responses of the aqueous PVA gels formed during F−T cycles in the presence of γ-CD can be controlled by adjustment of the PVA:γ-CD molar ratio employed during their gelation.}, number={25}, journal={MACROMOLECULES}, author={Hernandez, R and Rusa, M and Rusa, CC and Lopez, D and Mijangos, C and Tonelli, AE}, year={2004}, month={Dec}, pages={9620–9625} }
 @article{rusa_shuai_shin_bullions_wei_porbeni_lu_huang_fox_tonelli_2004, title={Controlling the behaviors of biodegradable/bioabsorbable polymers with cyclodextrins}, volume={12}, ISSN={["1572-8919"]}, DOI={10.1023/B:JOOE.0000038547.36750.78}, number={3}, journal={JOURNAL OF POLYMERS AND THE ENVIRONMENT}, author={Rusa, CC and Shuai, X and Shin, ID and Bullions, TA and Wei, M and Porbeni, FE and Lu, J and Huang, L and Fox, J and Tonelli, AE}, year={2004}, month={Jul}, pages={157–163} }
 @misc{rusa_wei_bullions_rusa_gomez_porbeni_wang_shin_balik_white_et al._2004, title={Controlling the polymorphic behaviors of semicrystalline polymers with cyclodextrins}, volume={4}, ISSN={["1528-7505"]}, DOI={10.1021/cg049821w}, abstractNote={We present a review of our initial studies concerning the control of polymorphism in semicrystalline polymers with cyclodextrins (CDs). CDs are cyclic starch oligomers with six (α-CD), seven (β-CD), and eight (γ-CD) α-1,4-linked glucose units possessing bracelet structures with hydrophobic and hydrophilic interiors and exteriors, respectively. They are able to act as hosts to form noncovalent inclusion compounds (ICs) with a large variety of guest molecules, including a wide range of high molecular weight guest polymers. In polymer-CD-ICs, the CD host crystalline lattice consists of hexagonally packed CD stacks with guest polymers occupying the narrow channels (∼0.5−1.0 nm) extending down the interiors of the stacked CDs. As a consequence, the included guest polymers must adopt highly extended conformations and are segregated from neighboring guest polymer chains. When the host CDs are appropriately removed from polymer-CD-ICs, the included guest polymers are forced to coalesce into a pure polymer solid, ...}, number={6}, journal={CRYSTAL GROWTH & DESIGN}, author={Rusa, CC and Wei, M and Bullions, TA and Rusa, M and Gomez, MA and Porbeni, FE and Wang, XG and Shin, ID and Balik, CM and White, JL and et al.}, year={2004}, pages={1431–1441} }
 @article{rusa_wei_shuai_bullions_wang_rusa_uyar_tonelli_2004, title={Molecular mixing of incompatible polymers through formation of and coalescence from their common crystalline cyclodextrin inclusion compounds}, volume={42}, ISSN={["1099-0488"]}, DOI={10.1002/polb.20272}, abstractNote={AbstractWe describe the successful mixing of polymer pairs and triplets that are normally incompatible to form blends that possess molecular‐level homogeneity. This is achieved by the simultaneous formation of crystalline inclusion compounds (ICs) between host cyclodextrins (CDs) and two or more guest polymers, followed by coalescing the included guest polymers from their common CD–ICs to form blends. Several such CD–IC fabricated blends, including both polymer1/polymer2 binary and polymer1/ polymer2/polymer3 ternary blends, are described and examined by means of X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and solid‐state NMR to probe their levels of mixing. It is generally observed that homogeneous blends with a molecular‐level mixing of blend components is achieved, even when the blend components are normally immiscible by the usual solution and melt blending techniques. In addition, when block copolymers composed of inherently immiscible blocks are coalesced from their CD–ICs, significant suppression of their normal phase‐segregated morphologies generally occurs. Preliminary observations of the thermal and temporal stabilities of the CD–IC coalesced blends and block copolymers are reported, and CD–IC fabrication of polymer blends and reorganization of block copolymers are suggested as a potentially novel means to achieve a significant expansion of the range of useful polymer materials. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4207–4224, 2004}, number={23}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Rusa, CC and Wei, M and Shuai, X and Bullions, TA and Wang, X and Rusa, M and Uyar, T and Tonelli, AE}, year={2004}, month={Dec}, pages={4207–4224} }
 @article{rusa_rusa_gomez_shin_fox_tonelli_2004, title={Nanostructuring high molecular weight isotactic polyolefins via processing with gamma-cyclodextrin inclusion compounds. Formation and characterization of polyolefin-gamma-cyclodextrin inclusion compounds}, volume={37}, ISSN={["1520-5835"]}, DOI={10.1021/ma0489164}, abstractNote={The present paper deals with the formation and detailed characterization of the γ-cyclodextrin (γ-CD) inclusion compounds (ICs) formed with two different high molecular weight isotactic polyolefins, i.e., polypropylene (i-PP) and poly(butene-1) (i-PB). Wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), solid-state 13C NMR, and FT-infrared (FTIR) observations were used to prove the inclusion of the guest polymer chains into the narrow channels provided by the stacks of the doughnut-shape CD molecules. The main aim of polyolefin inclusion into a solid host lattice like γ-CD is to extend and reorganize their conformations, with the hope of improving their commercial properties following their coalescence from their ICs. In the second part of the paper, both coalesced i-PP and i-PB obtained after the host γ-CD is removed reveal different characteristics as compared with the as-received or corresponding control samples.}, number={21}, journal={MACROMOLECULES}, author={Rusa, CC and Rusa, M and Gomez, M and Shin, ID and Fox, JD and Tonelli, AE}, year={2004}, month={Oct}, pages={7992–7999} }
 @article{peet_rusa_hunt_tonelli_balik_2005, title={Solid-state complexation of poly(ethylene glycol) with alpha-cyclodextrin}, volume={38}, ISSN={["1520-5835"]}, DOI={10.1021/ma048103f}, abstractNote={Low-molecular-weight liquid poly(ethylene glycol) (PEG) spontaneously forms an inclusion compound (IC) when combined with α-cyclodextrin (α-CD) powder at room temperature. This process can be followed with wide-angle X-ray diffraction (WAXD). The WAXD data shows that the α-CD crystals undergo a solid-state crystal−crystal transformation from the cage to the channel crystal structure upon IC formation over a period of about 8 h. The time dependence of the 2θ = 20° α-CD channel structure X-ray peak can be described by a simple first-order kinetic model. The effects of changing the temperature, PEG:α-CD molar ratio, PEG molecular weight, and vacuum-drying the CD have been studied. The barrier opposing the PEG inclusion-induced solid-state transformation of α-CD from the cage to the channel crystal structure appears to be dominated by changes in the packing/interactions of α-CDs, rather than the loss in the conformational entropy experienced by the PEG chains during the inclusion process.}, number={2}, journal={MACROMOLECULES}, author={Peet, J and Rusa, CC and Hunt, MA and Tonelli, AE and Balik, CM}, year={2005}, month={Jan}, pages={537–541} }
 @article{hunt_rusa_tonelli_balik_2004, title={Structure and stability of columnar cyclomaltohexaose (alpha-cyclodextrin) hydrate}, volume={339}, ISSN={["1873-426X"]}, DOI={10.1016/j.carres.2004.09.012}, abstractNote={Rapid recrystallization of cyclomaltohexaose (α-cyclodextrin, α-CD) from aqueous solution resulted in formation of the columnar crystal structure of α-CD containing only water as the guest molecule. Complementary water vapor sorption and wide-angle X-ray diffractometry (WAXD) experiments were performed on the α-CD columnar structure to elucidate the crystal structure present at varying sorption levels. Equilibrium isothermal water vapor sorption experiments at 40 °C revealed that the α-CD columnar structure is unstable above a water activity of approximately 0.67. This was confirmed by WAXD diffractograms collected over time, which further revealed that α-CD columnar structure undergoes a phase transformation to the cage structure after approximately 0.25 h at 40 °C and a water activity of 1.0.}, number={17}, journal={CARBOHYDRATE RESEARCH}, author={Hunt, MA and Rusa, CC and Tonelli, AE and Balik, CM}, year={2004}, month={Dec}, pages={2805–2810} }
 @article{topchieva_tonelli_panova_matuchina_kalashnikov_gerasimov_rusa_rusa_hunt_2004, title={Two-phase channel structures based on alpha-cyclodextrin-polyethylene glycol inclusion complexes}, volume={20}, ISSN={["0743-7463"]}, DOI={10.1021/la048970d}, abstractNote={Wide-angle X-ray scattering observations of α-cyclodextrin (CD)−poly(ethylene glycol) (PEG) inclusion complexes (ICs) have shown for the first time that two crystalline columnar modifications (forms I and II) are produced in the process of their formation. This was made possible by precise azimuthal X-ray diffraction scanning of oriented IC samples. Form I is characterized by CDs threaded onto PEG chains and arranged along channels in the order head-to-head/tail-to-tail, while form II is formed by unbound CDs also arranged into columns in a head-to-tail and also possibly a head-to-head/tail-to-tail manner, probably as a result of template crystallization on the form I IC crystals. It was shown that similar structural peculiarities are inherent for channel structures based on ICs obtained with PEG with a wide range of molecular weights (MWs). The characteristic feature of ICs based on PEG, especially with MW > 8000, is the presence of unbound polymer in the composition of the complex. The amount of unbound...}, number={21}, journal={LANGMUIR}, author={Topchieva, IN and Tonelli, AE and Panova, IG and Matuchina, EV and Kalashnikov, FA and Gerasimov, VI and Rusa, CC and Rusa, M and Hunt, MA}, year={2004}, month={Oct}, pages={9036–9043} }
 @article{rusa_fox_tonelli_2003, title={Competitive formation of polymer-cyclodextrin inclusion compounds}, volume={36}, ISSN={["1520-5835"]}, DOI={10.1021/ma021755o}, abstractNote={The hydrophobicity of the guest polymer and also the geometrical compatibility between guest polymer cross section and cavity diameter of the host cyclodextrin (CD) play important roles in the formation of inclusion compounds (ICs) between a mixture of one or two guest polymers with one or two different types of CDs, respectively. Specific polymer−CD interactions can be distinguished when, for example, polymer A−CD IC crystals are suspended in a solution containing polymer B, and a polymer B for polymer A exchange occurs, without CD−IC dissolution, during formation of polymer B−CD IC. When using the polymer pair poly(e-caprolactone) (PCL)/poly(l-lactic acid) (PLLA), we have observed that PLLA−α-CD IC is completely converted to PCL−α-CD IC, while the reverse polymer transfer is almost completely prohibited. α-CD host molecules also preferentially included PCL chains from a common PCL/PLLA solution. In addition, observation of the transfer of PCL from PCL−γ-CD IC crystals suspended in a solution containing ...}, number={8}, journal={MACROMOLECULES}, author={Rusa, CC and Fox, J and Tonelli, AE}, year={2003}, month={Apr}, pages={2742–2747} }
 @article{wei_bullions_rusa_wang_tonelli_2004, title={Unique morphological and thermal behaviors of reorganized poly(ethylene terephthalates)}, volume={42}, ISSN={["1099-0488"]}, DOI={10.1002/polb.10681}, abstractNote={AbstractBulk poly(ethylene terephthalate) PET has been reorganized both morphologically and conformationally by processing from its inclusion complex (IC) formed with γ‐cyclodextrin (CD). In the narrow channels of its γ‐CD‐IC crystals the included guest PET chains are isolated from neighboring PET chains and the ethylene glycol (EG) units adopt the highly extended g±tg∓ kink conformations, whose cross‐sectional diameters are ∼80% of the diameter of the fully extended, all‐trans crystalline PET conformer, though they are nearly (∼95%) as extended. When the highly extended, unentangled guest PET chains are coalesced from their γ‐CD‐IC crystals by exposure to hot water, host γ‐CDs are removed and the PET chains are presumably consolidated into a bulk sample with a morphology and constituent chain conformations not normally found in PET samples solidified from their randomly coiling, possibly entangled, disordered melts and solutions. Observations by polarized light and atomic force microscopies provide visual evidence for widely different semicrystalline morphologies developed in coalesced and as‐received PETs when crystallized from their melts, with possibly chain extended, small crystals and spherulitic, chain‐folded, large crystals, respectively. DSC observations reveal that coalesced PET is rapidly crystallizable from the melt, while as‐received PET is slow to crystallize and is easily quenched into a totally amorphous sample. Analyses of 13C‐NMR data strongly indicate that the PET chains in the noncrystalline regions of the coalesced sample remain predominantly in the highly extended kink conformations, with g±tg∓ EG units, which are required by their inclusion into PET‐γ‐CD‐IC crystals, while the predominantly amorphous PET chains in the as‐received sample have high concentrations of gauche± CH2CH2 and trans OCH2,CH2O EG bond conformations. 13C‐NMR T1(13C) and T1ρ(1H) relaxation studies show no evidence of a glass transition for coalesced PET, while the as‐received sample shows abrupt changes in both the MHz [T1(13C)] and kHz [T1ρ(1H)] motions at T ∼ Tg. Preliminary observations of differences in their macroscopic properties are attributed to the very different morphologies and conformations of the constituent chains in these PET samples. Apparently the kink conformers in the noncrystalline regions of coalesced PET are at least partially retained for extended periods even in the melt and are rapidly crystallized upon cooling. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 386–394, 2004}, number={3}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Wei, M and Bullions, TA and Rusa, CC and Wang, XW and Tonelli, AE}, year={2004}, month={Feb}, pages={386–394} }
 @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} }
 @article{bullions_edeki_porbeni_wei_shuai_rusa_tonelli_2003, title={Intimate blend of poly(ethylene terephthalate) and poly(ethylene 2,6-naphthalate) via formation with and coalescence from their common inclusion compound with gamma-cyclodextrin}, volume={41}, ISSN={["1099-0488"]}, DOI={10.1002/polb.10366}, abstractNote={AbstractThe experimental procedures to place poly(ethylene 2,6‐naphthalate) (PEN) guest molecules within γ‐cyclodextrin (γ‐CD) host molecules are described along with the subsequent verification of inclusion‐compound (IC) formation. In addition, the simultaneous complexing of PEN and poly(ethylene terephthalate) (PET) with γ‐CD to form their common IC is documented. Coalescence from their common γ‐CD IC generates an intimate blend of the PET and PEN polymers contained therein. Thermal analysis via differential scanning calorimetry reveals thermal behavior indicative of an intimate blend of PET and PEN. 1H NMR analysis confirms that the intimate blending of PET and PEN achieved by coalescence from their common γ‐CD IC is not due to transesterification into a PET/PEN copolymer during thermal analysis. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 139–148, 2003}, number={2}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Bullions, TA and Edeki, EM and Porbeni, FE and Wei, M and Shuai, X and Rusa, CC and Tonelli, AE}, year={2003}, month={Jan}, pages={139–148} }
 @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{rusa_luca_tonelli_rusa_2002, title={Structural investigations of the poly(epsilon-caprolactam)-urea inclusion compound}, volume={43}, ISSN={["0032-3861"]}, DOI={10.1016/s0032-3861(02)00225-2}, abstractNote={An interesting inclusion compound (IC) between guest poly(ε-caprolactam) (PεCL) and host urea was successfully obtained, for the first time, by co-crystallization from their common solution. X-ray diffraction, infrared spectroscopy and differential scanning calorimetry have been utilized for a detailed structural investigation of PεCL–urea IC (U IC) crystals. The results were compared with those obtained for well-known structures of the hexagonal polyethylene–U IC, the trigonal polyethylene oxide–U IC and the ‘large tetragonal’ poly(propylene)–U IC. The structure of PεCL–U IC reconfirms that the urea host molecules may crystallize, even in the presence of a rather slim polymer guest, into an IC with a lattice channel diameter of more than 5.25 Å.}, number={14}, journal={POLYMER}, author={Rusa, CC and Luca, C and Tonelli, AE and Rusa, M}, year={2002}, month={Jun}, pages={3969–3972} }
 @article{huang_gerber_taylor_lu_tapaszi_wutkowski_hill_funahlee_harvey_rusa_et al._2001, title={Creation of polymer films with novel structures and properties by processing with inclusion compounds}, volume={790}, DOI={10.1021/bk-2001-0790.ch014}, abstractNote={We have begun to fabricate polymer films whose compositions, structures, and properties may be developed and controlled during their formation with inclusion compounds (ICs). ICs formed with either urea(U) or cyclodextrin(CD) hosts and containing guest polymers or small-molecule additives are embedded into carrier polymer films either by solution casting or melt pressing methods. Once embedded, the IC crystals are left undisturbed or are disrupted by solvent treatment, which removes the host (U or CD), but not the carrier polymer nor the coalesced IC-guest. In this manner polymer-polymer composite and additive-filled films have been fabricated. Employment of polymer-U or CD-ICs produces composite films containing two different polymers or two populations of the same polymer. In the latter case, the morphologies of the carrier and IC-coalesced chains may differ, because of chain-folded and chain-extended crystallization, respectively. We may, for example, control film permeabilities by either controlling the compositions or the morphologies of}, journal={ACS Symposium Series}, author={Huang, L. and Gerber, M. and Taylor, H. and Lu, J. and Tapaszi, E. and Wutkowski, M. and Hill, M. and Funahlee, F. N. and Harvey, A. and Rusa, C. C. and et al.}, year={2001} }
 @article{rusa_luca_tonelli_2001, title={Polymer-cyclodextrin inclusion compounds: Toward new aspects of their inclusion mechanism}, volume={34}, ISSN={["0024-9297"]}, DOI={10.1021/ma001868c}, abstractNote={α-Cyclodextrin inclusion compounds were prepared in the presence of a polymer and a small molecule model for the polymer repeat unit. By means of this technique, we are able to demonstrate that α-cyclodextrin prefers the inclusion of the longer molecular chain guest. Comparison of the cyclodextrin inclusion compounds formed with poly(e-caprolactone) and hexanoic acid, separately and from solution containing both poly(e-caprolactone) and hexanoic acid in varying amounts, enables us to draw certain conclusions concerning both the thermodynamic and kinetic aspects of poly(e-caprolactone)−α-cyclodextrin inclusion compound formation. Differential scanning calorimetry, Fourier transform infrared, and wide-angle X-ray diffraction have been used to verify the formation and successfully characterize all inclusion compounds.}, number={5}, journal={MACROMOLECULES}, author={Rusa, CC and Luca, C and Tonelli, AE}, year={2001}, month={Feb}, pages={1318–1322} }