About

Professor Alan Tonelli’s research interests include the conformations, configurations, and structures of synthetic and biological polymers, their determination by NMR, and establishing their effects on the physical properties of polymers. He has pursued the formation and study of molecular composites formed by embedding inclusion compounds (ICs) between host cyclic starches (cyclodextrins, CDs) containing 6 (α), 7 (β), and 8 (γ) glucose units and polymer or small molecule guests into polymer fibers and films, followed by the release and coalescence of the guest into the carrier polymer phase. His work aims to develop new fabrication methods that enable the delivery of various additives to polymer fibers and films, which he considers superior to current technologies. Professor Tonelli has demonstrated that CDs can act as hosts in the formation of inclusion compounds with guest polymers, resulting in crystalline materials with unique morphologies and properties. His studies include analyzing the motional parameters of polymer-CD-ICs using NMR techniques, exploring the structural reorganization during coalescence, and creating well-mixed polymer blends from CD-ICs. His recent focus involves characterizing the microstructural elements of synthetic polymers using 13C-NMR and Kerr-Effect examination, which allows for the determination of complete molecular architectures. His work has significant implications for developing polymer materials with enhanced or novel properties, including the creation of stable, heat-resistant morphologies and recyclable nucleants, with potential benefits for industry and society.

Research topics

• Nanotechnology
• Chemistry
• Organic chemistry
• Materials science
• Medicine
• Biomedical engineering

Selected publications

• Carbon‐Based Bifunctional Lewis/Brønsted Acid Catalysts for 5‐HMF Production from Cellobiose

  ChemCatChem · 2025-03-25 · 2 citations

  articleOpen access1st author

  Abstract Bifunctional carbon‐based acid catalysts presenting Brønsted and Lewis acid sites in different proportions were synthesized by grafting mesoporous aluminosilicate patches in coexistence with benzyl sulfonic moieties on the solid's surface. The final bifunctional systems were obtained by development of a methodology allowing the production of a model discontinuous silica layer on the carbon substrate before applying the optimized procedure to the desired alumino‐silicate layer. Patches were necessary to expose bare carbon surfaces for sulfonic acid grafting employing a diazonium coupling methodology to ensure robust anchoring. The bifunctional solids and their monofunctional counterparts were fully characterized and their acidic nature, together with the presence of both Brønsted and Lewis acid sites, was assessed by Py‐FTIR spectroscopy, NH 3 ‐TPD, solid‐state 31 P MAS NMR, and Boehm back titration. The attainment of a mesoporous discontinuous oxide framework was confirmed by nitrogen physisorption and SEM/TEM observations. Finally, the catalytic performance of both the produced bifunctional systems and their monofunctional counterparts was investigated and compared for the upgrading of cellobiose to 5‐hydroxymethylfurfural (5‐HMF). A maximal yield of 37% of 5‐HMF out of a 96% of cellobiose conversion was attained after 23 h with catalyst I4@BATEOS/SO 3 H in a designed solvent mixture (THF:mQ water) at 423 K.

  PublisherOA PDFDOI

• Conformation and Configuration

  Encyclopedia of Polymer Science and Technology · 2023-03-31 · 1 citations

  other1st authorCorresponding

  Abstract The unique feature of polymers is the flexibility of their long chains, achieved by rotation about their many backbone bonds, which enable them to assume an extremely large number of different Conformations. This is the source of their unique material behaviors, such as rubber‐like elasticity and their time and processing dependencies. Polymer conformations and material properties depend upon their Configurations, among which are the mode of enchainment of diene monomers, regiosequences (directions of monomer insertion), the stereosequences (stereochemical arrangements of atoms in the polymer chain), co‐monomer sequences of vinyl polymers, branches, and cross‐links. Polymer configurations cannot be altered without breaking and reforming their covalent bonds. In this article, we describe how the conformational characteristics of polymers can be rigorously treated, with account explicitly taken of their configurations, and how various conformationally averaged chain properties can be connected to the behaviors of their materials to allow improved structure–property relations. As examples, because 13 C NMR resonances depend on local polymer microstructures, the average bond conformation probabilities calculated for each microstructure can be used to assign their resonances. The applied to its dilute solution (the Kerr‐Effect) is very sensitive to the Configuration/Macrostructure of the overall polymer chain. When compared to the molar Kerr constants (mK) calculated for chains possessing the microstructures determined by 13 C NMR, the Macrostructures or complete molecular architectures of polymer chains may be revealed.

  PublisherDOI

• Conformational Source of Comonomer Sequence-Dependent Copolymer Glass-Transition Temperatures

  ChemRxiv · 2023-10-19 · 1 citations

  preprintOpen access1st authorCorresponding

  This brief review addresses the source of the dependence of copolymer glass transition temperatures (Tgps) on their comonomer sequences. Here we show that a comparison of the conformational entropies obtained from the Rotational Isomeric State (RIS) conformational models of the poly-A and poly-B homopolymers and their resultant poly-A/B co-polymers, i.e., ΔSconf = (XASA + XBSB) - SA/B (X = comonomer fraction), can be used to predict/understand the Tgps of copolymers. For copolymers with ΔSconf ~ 0, we expect their Tgps to follow Fox behavior and to depend only on copolymer composition, because of the similar conformational flexibilities of the A and B homo- and A/B-copolymers. When the conformational entropy ΔSconf is negative the A/B copolymer is assumed more flexible than the weighted sum of polymer-A and polymer-B conformational entropies, resulting in Tgps that are lower than expected from the Fox equation. Conversely, a positive ΔSconf suggests the copolymer’s lower flexibility, resulting in higher Tgps than expected from the Fox relation. We use the successful comparison of the observed dependence of numerous copolymer Tgps to demonstrate the validity of using their calculated RIS conformational entropies to predict their comonomer sequence dependencies.

  PublisherOA PDFDOI

• Potential Replacement of Toxic PVC Plasticizers with Urea, Its Derivatives, and Related Compounds

  ChemRxiv · 2023-06-26

  preprintOpen accessSenior author

  The primary plasticizers for the world’s most plasticized polymer, poly(vinyl chloride) (PVC), are organic phthalates, this despite being categorized as probable human carcinogens by the EPA. Di-2-ethylhexyl phthalate (DEHP or DOP) is such a typical PVC plasticizer. We sought to find an alternative plasticizer that lowered the glass transition temperature (Tg) and softened PVC, but was not as harmful to the environment and for our health as the currently employed phthalate plasticizers. We recently discovered that urea (U) could complex with amorphous polymers, such as atactic poly(methyl methacrylate) (PMMA) and poly(vinyl acetate) (PVAc). Compared to neat samples, the Tgs of the PMMA-U and PVAc-U complexes were increased and decreased, respectively. However, when complexed with dimethylurea (DMU), the Tg of the PMMA-DMU complex was lowered. Since Tgs of PMMA and PVAc were lowered by either U or one of its derivatives, this prompted us to investigate whether they could interact and complex with another largely amorphous polymer PVC, that is often plasticized, to soften and lower its Tg. Shifts in the vibrational frequencies observed by Fourier-Transform Infrared spectroscopy and Differential Scanning Calorimetry thermograms indicated that U, its derivative tetramethylurea (TMU)], and the related compound Acetamide (AC) were complexing with PVC. All three complexes (PVC-U, -TMU, and –AC) showed significantly lowered Tgs. Preliminary mechanical property measurements of PVC-U and PVC-AC films showed they were softer and more pliable than PVC films. Consequently, we believe our preliminary results warrant further examination of U, AC, and TMU as potential effective and less harmful PVC plasticizers.

  PublisherOA PDFDOI

• Chitosan based bioadhesives for biomedical applications: A review

  Carbohydrate Polymers · 2022 · 261 citations

  • Biomedical engineering
  • Nanotechnology
  • Chemistry
  PublisherDOI

• External Stimuli Responsive Nanofibers in Biomedical Engineering

  Advances in polymer science · 2022-01-01

  book-chapterSenior author
  PublisherDOI

• Chitosan/Graphene Oxide Composite Films and Their Biomedical and Drug Delivery Applications: A Review

  Applied Sciences · 2021-08-24 · 38 citations

  reviewOpen accessCorresponding

  The healing of wounds is still a challenging clinical problem for which an efficient and fast treatment is needed. Therefore, recent studies have created a new generation of wound dressings that can accelerate the wound healing process with minimal side effects. Chitosan, a natural biopolymer, is an attractive candidate for preparing biocompatible dressings. The biodegradability, non-toxicity, and antibacterial activities of chitosan have made it a promising biopolymer for treating wounds. Graphene oxide has also been considered by researchers as a non-toxic, inexpensive, and biocompatible material for wound healing applications. This review paper discusses the potential use of chitosan/graphene oxide composite films and their application in wound dressing and drug delivery systems.

  PublisherOA PDFDOI

• Cyclodextrin-based nanostructures

  Progress in Materials Science · 2021 · 111 citations

  Senior authorCorresponding
  • Materials science
  • Nanotechnology
  • Organic chemistry
  PublisherDOI

• Polymer Physics or Why Polymers and Their Materials Can Behave in Unique Ways

  2020-04-03

  book-chapter1st authorCorresponding
  PublisherDOI

• Preface

  ACS symposium series · 2020-01-01

  other1st authorCorresponding

  ADVERTISEMENT RETURN TO BOOKPREVChapterNEXTPrefaceAlan E. TonelliAlan E. Tonelli Wilson College of Textiles North Carolina State University 1020 Main Campus Drive Raleigh, North Carolina 27606-8301, United States More by Alan E. Tonelli and Gary PattersonGary Patterson Department of Chemistry Carnegie Mellon University 3725 Wauna Vista Drive Vancouver, Washington 98661, United States More by Gary PattersonDOI: 10.1021/bk-2020-1356.pr001 This publication is free to access through this site. Learn MorePublication Date (Web):September 15, 2020Publication History Published online15 September 2020Published inprint 1 January 2020Request reuse permissions Copyright © 2020 American Chemical Society. This publication is available under these Terms of Use. Modern Applications of Flory's "Statistical Mechanics of Chain Molecules"pp ix-xACS Symposium SeriesVol. 1356ISBN13: 9780841298866eISBN: 9780841298859Chapter Views151Citations-LEARN ABOUT THESE METRICSChapter 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. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (1 MB) Get e-Alerts

  PublisherDOI

Recent grants

• Characterization of Polymers with the Kerr-Effect

  NSF · $360k · 2010–2014

Frequent coauthors

• Frederic C. Schilling

  North Carolina State University

  74 shared

• Marián A. Gómez-Fatou

  Universidad Autónoma de Nuevo León

  68 shared

• Cristian C. Rusa

  Norfolk State University

  57 shared

• Marcus A. Hunt

  44 shared

• Jialong Shen

  Guilin University of Technology

  37 shared

• I. D. Shin

  Korea Advanced Institute of Science and Technology

  35 shared

• Mariana Rusa

  Norfolk State University

  33 shared

• C. M. Balik

  32 shared

Awards & honors

• American Chemical Society – National Counselor
• American Chemical Society – Tour speaker
• North Carolina Polymer Group of the American Chemical Societ…