@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{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{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{shuai_porbeni_wei_bullions_tonelli_2002, title={Formation of inclusion complexes of poly(3-hydroxybutyrate)s with cyclodextrins. 1. Immobilization of atactic poly(R,S-3-hydroxybutyrate) and miscibility enhancement between poly(R,S-3-hydroxybutyrate) and poly(epsilon-caprolactone)}, volume={35}, ISSN={["0024-9297"]}, DOI={10.1021/ma011954s}, abstractNote={Atactic poly(R,S-3-hydroxybutyrate) (a-PHB) was synthesized by anionic polymerization of β-butyrolactone with potassium methoxide as an initiator. This completely amorphous polyester is capable of forming a crystalline inclusion complex (IC) with γ-cyclodextrin (γ-CD) adopting a channel structure. There is no evidence showing that a-PHB may form IC with either α-CD or β-CD. On the basis of these discoveries, a common IC was formed with two polymer chains, a-PHB and poly(e-caprolactone) (PCL), randomly distributed into the channels of γ-CD-PCL/a-PHB IC crystals. Nevertheless, in the formation of the common IC, PCL inclusion appears superior to a-PHB inclusion. Therefore, the molar ratio of a-PHB and PCL in the coalesced sample has been detected to be lower than that used in the formation of the common IC. Washing the common IC with hot water removed the γ-CD, and the molecular chains of the two polymers were coalesced. Very interestingly, only a single glass transition temperature (Tg), dependent on the co...}, number={8}, journal={MACROMOLECULES}, author={Shuai, XT and Porbeni, FE and Wei, M and Bullions, T and Tonelli, AE}, year={2002}, month={Apr}, pages={3126–3132} }
 @article{shuai_porbeni_wei_bullions_tonelli_2002, title={Inclusion complex formation between alpha,gamma-cyclodextrins and a triblock copolymer and the cyclodextrin-type-dependent microphase structures of their coalesced samples}, volume={35}, ISSN={["0024-9297"]}, DOI={10.1021/ma012085+}, abstractNote={A triblock copolymer (PCL−PPG−PCL, Mn = 1.38 × 104) of poly(e-caprolactone) (PCL) and poly(propylene glycol) (PPG) was synthesized by ring-opening polymerization of e-caprolactone. Cyclodextrin (CD)-type-dependent formation of inclusion complexes (ICs) between cyclodextrins and this triblock copolymer was studied. Only PCL blocks were included as guests in the IC formed with α-cyclodextrin (α-CD), while both PCL and PPG blocks were included in the IC formed with γ-cyclodextrin (γ-CD). As a result, the copolymer coalesced from its IC crystals with α-CD showed an increased crystallinity, while to the contrary, the copolymer coalesced from its IC crystals with γ-CD exhibited a decreased crystallinity, when both were compared to the as-synthesized triblock copolymer. Fourier transform infrared (FTIR) spectra, 13C CP/MAS solid-state NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and wide-angle X-ray diffraction (WAXD) measurements were employed to study the formation of ICs as ...}, number={6}, journal={MACROMOLECULES}, author={Shuai, XT and Porbeni, FE and Wei, M and Bullions, T and Tonelli, AE}, year={2002}, month={Mar}, pages={2401–2405} }
 @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{bullions_wei_porbeni_gerber_peet_balik_white_tonelli_2002, title={Reorganization of the structures, morphologies, and conformations of bulk polymers via coalescence from polymer-cyclodextrin inclusion compounds}, volume={40}, ISSN={["1099-0488"]}, DOI={10.1002/polb.10152}, abstractNote={AbstractBulk poly(ethylene terephthalate) (PET) and bisphenol A polycarbonate (PC) samples have been produced by the coalescence of their segregated, extended chains from the narrow channels of the crystalline inclusion compounds (ICs) formed between the γ‐cyclodextrin (CD) host and PET and PC guests, which are reported for the first time. Differential scanning calorimetry, Fourier transform infrared, and X‐ray observations of PET and PC samples coalesced from their crystalline γ‐CD‐ICs suggest structures and morphologies that are different from those of samples obtained by ordinary solution and melt processing techniques. For example, as‐received PC is generally amorphous with a glass‐transition temperature (Tg) of about 150 °C; when cast from tetrahydrofuran solutions, PC is semicrystalline with a melting temperature (Tm) of about 230 °C; and after PC/γ‐CD‐IC is washed with hot water for the removal of the host γ‐CD and for the coalescence of the guest PC chains, it is semicrystalline but has an elevated Tm value of about 245 °C. PC crystals formed upon the coalescence of highly extended and segregated PC chains from the narrow channels in the γ‐CD host lattice are possibly more chain‐extended and certainly more stable than chain‐folded PC crystals grown from solution. Melting the PC crystals formed by coalescence from PC/γ‐CD‐IC produces a normal amorphous PC melt that, upon cooling, results in typical glassy PC. PET coalesced from its γ‐CD‐IC crystals, although also semicrystalline, displays a Tm value only marginally elevated from that of typical bulk or solution‐crystallized PET samples. However, after the melting of γ‐CD‐IC‐coalesced PET crystals, it is difficult to quench the resultant PET melt into the usual amorphous PET glass, characterized by a Tg value of about 80 °C. Instead, the coalesced PET melt rapidly recrystallizes during the attempted quench, and so upon reheating, it displays neither a Tg nor a crystallization exotherm but simply remelts at the as‐coalesced Tm. This behavior is unaffected by the coalesced PET sample being held above Tm for 2 h, indicating that the extended, unentangled nature of the chains in the noncrystalline regions of the coalesced PET are not easily converted into the completely disordered, randomly coiled, entangled melt. Apparently, the highly extended, unentangled characters of the PC and PET chains in their γ‐CD‐ICs are at least partially retained after they are coalesced. Initial differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared, and X‐ray observations are described here. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 992–1012, 2002}, number={10}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Bullions, TA and Wei, M and Porbeni, FE and Gerber, MJ and Peet, J and Balik, M and White, JL and Tonelli, AE}, year={2002}, month={May}, pages={992–1012} }
 @article{shuai_probeni_wei_bullions_tonelli_2002, title={Stereoselectivity in the formation of crystalline inclusion complexes of poly(3-hydroxybutyrate)s with cyclodextrins}, volume={35}, ISSN={["0024-9297"]}, DOI={10.1021/ma012038h}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTStereoselectivity in the Formation of Crystalline Inclusion Complexes of Poly(3-hydroxybutyrate)s with CyclodextrinsXintao Shuai, Francis E. Porbeni, Min Wei, Todd Bullions, and Alan E. TonelliView Author Information Fiber and Polymer Science Program, College of Textiles, North Carolina State University, Raleigh, North Carolina 27695-8301 Cite this: Macromolecules 2002, 35, 9, 3778–3780Publication Date (Web):March 26, 2002Publication History Received21 November 2001Revised15 February 2002Published online26 March 2002Published inissue 1 April 2002https://pubs.acs.org/doi/10.1021/ma012038hhttps://doi.org/10.1021/ma012038hbrief-reportACS PublicationsCopyright © 2002 American Chemical SocietyRequest reuse permissionsArticle Views421Altmetric-Citations62LEARN 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:Cadmium sulfide,Cavities,Conformation,Physical and chemical processes,Polymers Get e-Alerts}, number={9}, journal={MACROMOLECULES}, author={Shuai, XT and Probeni, FE and Wei, M and Bullions, T and Tonelli, AE}, year={2002}, month={Apr}, pages={3778–3780} }
 @article{shuai_wei_porbeni_bullions_tonelli_2002, title={Formation of and coalescence from the inclusion complex of a biodegradable block copolymer and alpha-cyclodextrin. 2: A novel way to regulate the biodegradation behavior of biodegradable block copolymers}, volume={3}, ISSN={["1526-4602"]}, DOI={10.1021/bm015609m}, abstractNote={A biodegradable block copolymer (PCL-b-PLLA, M(n) = 1.72 x 10(4), M(w)/M(n) = 1.37) of poly(epsilon-caprolactone) (PCL) and poly(L-lactide) (PLLA) with very low crystallinity was obtained by forming the inclusion complex between alpha-cyclodextrin molecules and PCL-b-PLLA followed by coalescence of the guest polymer chains. Films of the as-synthesized and coalesced copolymer samples, PCL and PLLA homopolymers of approximately the same chain lengths as the corresponding blocks of PCL-b-PLLA, and a physical blend of PCL/PLLA homopolymers with the same molar composition as PCL-b-PLLA were prepared by melt-compression molding between Teflon plates. Subsequently, the in vitro biodegradation behavior of these films was studied in phosphate buffer solution containing lipase from Rhizopus arrhizus, by means of ultraviolet spectra, attenuated total reflectance FTIR spectra, differential scanning calorimetry, wide-angle X-ray diffraction measurements, and weight loss analysis. PCL segments were found to degrade much faster than PLLA segments, both in the pure state and in copolymer or blend samples. Consistent with our expectation, suppression of the phase separation, as well as a decrease of crystallinity, in the coalesced copolymer sample led to a much faster enzymatic degradation than that of either as-synthesized copolymer or the PCL/PLLA physical blend sample, especially during the early stages of biodegradation. Thus the biodegradation behavior of biodegradable block copolymers, which is of decisive importance in drug delivery and controlled release systems, may be regulated by the novel and convenient means recently reported by us.(1)}, number={1}, journal={BIOMACROMOLECULES}, author={Shuai, XT and Wei, M and Porbeni, FE and Bullions, TA and Tonelli, AE}, year={2002}, pages={201–207} }