1
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Tiwari N, Badiger MV, Rajamohanan PR, Ravindranathan S. Investigation of domain structures in
MPEG‐
b
‐PCL
grafted poly(acrylic acid) by
NMR
diffusion studies. POLYM INT 2022. [DOI: 10.1002/pi.6380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Neha Tiwari
- Faculty of Engineering Sciences and Bavarian Polymer Institute University of Bayreuth, Ludwig Thoma Str. 36 A 95447 Bayreuth Germany
| | - Manohar V. Badiger
- Polymer Science and Engineering Division CSIR‐National Chemical Laboratory Pune 411008 India
| | - P. R. Rajamohanan
- Central NMR Facility CSIR‐National Chemical Laboratory Pune 411008 India
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2
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Molybdenum disulfide (MoS2) nanosheets-based hydrogels with light-triggered self-healing property for flexible sensors. J Colloid Interface Sci 2021; 586:601-612. [DOI: 10.1016/j.jcis.2020.10.128] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 01/01/2023]
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3
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Lee SS, Kim HD, Kim SHL, Kim I, Kim IG, Choi JS, Jeong J, Kim JH, Kwon SK, Hwang NS. Self-Healing and Adhesive Artificial Tissue Implant for Voice Recovery. ACS APPLIED BIO MATERIALS 2018; 1:1134-1146. [DOI: 10.1021/acsabm.8b00349] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Seunghun S. Lee
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Hwan D. Kim
- School of Chemical and Biological Engineering, The Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Seung Hyun L. Kim
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Inseon Kim
- School of Chemical and Biological Engineering, The Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - In Gul Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Ji Suk Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Jiwoon Jeong
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Jung Hun Kim
- School of Chemical and Biological Engineering, The Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Seong Keun Kwon
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul 03080, Republic of Korea
| | - Nathaniel S. Hwang
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, The Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
- BioMAX/N-Bio Institute, Seoul National University, Seoul 08826, Republic of Korea
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4
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D'Agostino C, Liuzzi R, Gladden LF, Guido S. Swelling-induced structural changes and microparticle uptake of gelatin gels probed by NMR and CLSM. SOFT MATTER 2017; 13:2952-2961. [PMID: 28358151 DOI: 10.1039/c6sm02811j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Gelatin gels are increasingly involved in many industrial applications due to several advantages including cost efficiency and biocompatibility. Generally, their production requires the use of aqueous solvents, which cause significant swelling, due to the ability of solvent molecules to penetrate through the gel microstructure and increase its volume. Since swelling mechanisms and their effect on the gel structure are not fully understood, further investigations are required. In this work, we combine macroscopic measurements of the swelling ratio (SR) with Nuclear Magnetic Resonance (NMR) and Confocal Laser Scanning Microscopy (CLSM) to investigate changes in the gelatin structure as a function of both polymer concentration and swelling time. SR values increase as a function of time until a maximum is reached and then show a slight drop for all the gelatin concentrations after 24 h swelling time, probably due to a network relaxation process. NMR allows determination of mass transport and molecular dynamics of water inside the gelatin pores, while CLSM is used to visualize the penetration of tracers (polystyrene microbeads) with a diameter much larger than the gel pores. Structural parameters, such as average pore size and tortuosity, are estimated. In particular, the pore size decreases for higher polymer concentration and increases during swelling, until reaching a maximum, and then dropping at longer times. The penetration of tracers provides evidence of the heterogeneity of the gel structure and shows that single microcarriers can be loaded in gelatin gels upon swelling.
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Affiliation(s)
- Carmine D'Agostino
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK.
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5
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Yan X, Chen Q, Zhu L, Chen H, Wei D, Chen F, Tang Z, Yang J, Zheng J. High strength and self-healable gelatin/polyacrylamide double network hydrogels. J Mater Chem B 2017; 5:7683-7691. [DOI: 10.1039/c7tb01780d] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Gelatin/polycrylamide double-network (DN) hydrogels composed of two different polymer networks with strong asymmetry are excellent structural platforms to integrate different mechanical properties into a single material.
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Affiliation(s)
- Xiaoqiang Yan
- School of Materials Science and Engineering
- Henan Polytechnic University
- Jiaozuo
- China
| | - Qiang Chen
- School of Materials Science and Engineering
- Henan Polytechnic University
- Jiaozuo
- China
| | - Lin Zhu
- School of Materials Science and Engineering
- Henan Polytechnic University
- Jiaozuo
- China
| | - Hong Chen
- Department of Chemical and Biomolecular Engineering
- The University of Akron
- Akron
- USA
| | - Dandan Wei
- School of Materials Science and Engineering
- Henan Polytechnic University
- Jiaozuo
- China
| | - Feng Chen
- School of Materials Science and Engineering
- Henan Polytechnic University
- Jiaozuo
- China
| | - Ziqing Tang
- School of Materials Science and Engineering
- Henan Polytechnic University
- Jiaozuo
- China
| | - Jia Yang
- School of Materials Science and Engineering
- Henan Polytechnic University
- Jiaozuo
- China
| | - Jie Zheng
- Department of Chemical and Biomolecular Engineering
- The University of Akron
- Akron
- USA
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6
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Šaman D, Kolehmainen E. Studies on supramolecular gel formation using DOSY NMR. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2015; 53:256-260. [PMID: 25631685 DOI: 10.1002/mrc.4185] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 10/15/2014] [Accepted: 10/17/2014] [Indexed: 06/04/2023]
Abstract
Herein, we present the results obtained from our studies on supramolecular self-assembly and molecular mobility of low-molecular-weight gelators (LMWGs) in organic solvents using pulsed field gradient (PFG) diffusion ordered spectroscopy (DOSY) NMR. A series of concentration-dependent DOSY NMR experiments were performed on selected LMWGs to determine the critical gelation concentration (CGC) as well as to understand the behaviour of the gelator molecules in the gel state. In addition, variable-temperature DOSY NMR experiments were performed to determine the gel-to-sol transition. The PFG NMR experiments performed as a function of gradient strength were further analyzed using monoexponential DOSY processing, and the results were compared with the automated Bayesian DOSY transformation to obtain 2D plots. Our results provide useful information on the stepwise self-assembly of small molecules leading to gelation. We believe that the results obtained from these experiments are applicable in determining the CGC and gel melting temperatures of supramolecular gels.
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7
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Skewis LR, Lebedeva T, Papkov V, Thayer EC, Massefski W, Cuker A, Nagaswami C, Litvinov RI, Kowalska MA, Rauova L, Poncz M, Weisel JW, Lowery TJ, Cines DB. T2 magnetic resonance: a diagnostic platform for studying integrated hemostasis in whole blood--proof of concept. Clin Chem 2014; 60:1174-82. [PMID: 24958814 DOI: 10.1373/clinchem.2014.223735] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Existing approaches for measuring hemostasis parameters require multiple platforms, can take hours to provide results, and generally require 1-25 mL of sample. We developed a diagnostic platform that allows comprehensive assessment of hemostatic parameters on a single instrument and provides results within 15 min using 0.04 mL of blood with minimal sample handling. METHODS T2 magnetic resonance (T2MR) was used to directly measure integrated reactions in whole blood samples by resolving multiple water relaxation times from distinct sample microenvironments. Clotting, clot contraction, and fibrinolysis stimulated by thrombin or tissue plasminogen activator, respectively, were measured. T2MR signals of clotting samples were compared with images produced by scanning electron microscopy and with standard reference methods for the following parameters: hematocrit, prothrombin time, clot strength, and platelet activity. RESULTS Application of T2MR methodology revealed conditions under which a unique T2MR signature appeared that corresponded with the formation of polyhedral erythrocytes, the dynamics and morphology of which are dependent on thrombin, fibrinogen, hematocrit, and platelet levels. We also showed that the T2MR platform can be used for precise and accurate measurements of hematocrit (%CV, 4.8%, R(2) = 0.95), clotting time (%CV, 3.5%, R(2) = 0.94), clot strength (R(2) = 0.95), and platelet function (93% agreement with light transmission aggregometry). CONCLUSIONS This proof-of-concept study demonstrates that T2MR has the potential to provide rapid and sensitive identification of patients at risk for thrombosis or bleeding and to identify new biomarkers and therapeutic targets with a single, simple-to-employ analytic approach that may be suitable for routine use in both research and diverse clinical settings.
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Affiliation(s)
| | - Tatiana Lebedeva
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | | | | | | | - Adam Cuker
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Chandrasekaran Nagaswami
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Rustem I Litvinov
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - M Anna Kowalska
- Institute of Medical Biology, Polish Academy of Science, Lodz, Poland; Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Lubica Rauova
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Mortimer Poncz
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - John W Weisel
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Douglas B Cines
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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8
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Liebi M, Kuster S, Kohlbrecher J, Ishikawa T, Fischer P, Walde P, Windhab EJ. Magnetically enhanced bicelles delivering switchable anisotropy in optical gels. ACS APPLIED MATERIALS & INTERFACES 2014; 6:1100-1105. [PMID: 24369041 DOI: 10.1021/am4046469] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Mesostructures responding to external triggers such as temperature, pH, or magnetic field have the potential to be used as self-acting sensors, detectors, or switches. Key features are a strong and well-defined response to the external trigger. Here, we present magnetic alignable bicelles embedded into a gelatin matrix generating magnetically switchable structures, which can reversibly be locked and unlocked by adjusting the temperature. We show that the disk-like aggregates can be orientated in magnetic fields, and such orientation can be preserved after embedding into gelatin. The resulting gel cubes show an anisotropic transfer for electromagnetic waves, i.e., a different spatial birefringence. Cycling through the melting point of gelatin sets the structure back to its isotropic state providing a read-out of the thermal history. Stacking of the bicelles induced by the gelatin promotes magnetic aligning, as an increased aggregation number in the stacks increases the magnetic orientation energy.
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Affiliation(s)
- Marianne Liebi
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
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9
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Dama M, Berger S. Study of an Organogelator by Diffusion-Ordered NMR Spectroscopy. J Phys Chem B 2013; 117:5788-91. [DOI: 10.1021/jp401963t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Murali Dama
- Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103 Leipzig,
Germany
| | - Stefan Berger
- Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103 Leipzig,
Germany
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10
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Le Feunteun S, Ouethrani M, Mariette F. The rennet coagulation mechanisms of a concentrated casein suspension as observed by PFG-NMR diffusion measurements. Food Hydrocoll 2012. [DOI: 10.1016/j.foodhyd.2011.09.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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11
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Pelc D, Marion S, Basletić M. Four-contact impedance spectroscopy of conductive liquid samples. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:073907. [PMID: 21806199 DOI: 10.1063/1.3609867] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present an improved approach to the impedance spectroscopy of conductive liquid samples using four-electrode measurements. Our method enables impedance measurements of conductive liquids down to the sub-Hertz frequencies, avoiding the electrode polarization effects that usually cripple standard impedance analysers. We have successfully tested our apparatus with aqueous solutions of potassium chloride and gelatin. The first substance has shown flat spectra from ~100 kHz down to sub-Hz range, while the results on gelatin clearly show the existence of two distinct low frequency conductive relaxations.
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Affiliation(s)
- Damjan Pelc
- Department of Physics, Faculty of Science, University of Zagreb, Croatia
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12
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Melito H, Daubert C. Rheological Innovations for Characterizing Food Material Properties. Annu Rev Food Sci Technol 2011; 2:153-79. [DOI: 10.1146/annurev-food-022510-133626] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rheological methods are continually evolving to encompass novel technologies and measurement methods. This review highlights novel techniques used to analyze the rheological properties of foods over the previous decade. Techniques reviewed include large amplitude oscillatory shear (LAOS) testing and rheological techniques coupled with other measurement methods, such as microscopy and nuclear magnetic resonance (NMR). Novel techniques are briefly overviewed and discussed in terms of advantages and disadvantages, previous use, and suggested future utilization.
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Affiliation(s)
- H.S. Melito
- Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - C.R. Daubert
- Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina 27695
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13
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Ghoshal S, Mattea C, Stapf S. Inhomogeneity in the drying process of gelatin film formation: NMR microscopy and relaxation study. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2009.12.064] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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14
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Zhu W, Shi C, Xiao H. Density functional theory study of high-pressure behavior of crystalline hexanitrostilbene. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2009.06.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Zhu W, Zhang X, Wei T, Xiao H. DFT studies of pressure effects on structural and vibrational properties of crystalline octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine. Theor Chem Acc 2009. [DOI: 10.1007/s00214-009-0596-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Piñeiro Y, López-Quintela MA, Rivas J, Leisner D. Percolation threshold and scattering power law of gelatin gels. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:041409. [PMID: 19518235 DOI: 10.1103/physreve.79.041409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 01/22/2009] [Indexed: 05/27/2023]
Abstract
Gelation of gelatin was broadly studied by experimental and theoretical methods. Power laws observed on the gel point-mainly obtained by dynamic light scattering (DLS)-are considered to be the signature of some special dynamic phenomena ascribed to the appearance of a percolation cluster. We present here experimental (DLS and rheometric measurements) and Monte Carlo simulation studies showing that the percolation threshold and DLS power-law decay occur on different times. We ascribe the percolation point to the time where the scattering medium mode diverges. This mode is sensitive to the clusters' growth and diverges when the system attains the percolation threshold. The power-law behavior is obtained only in the postpercolation regime.
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Affiliation(s)
- Y Piñeiro
- Department of Applied Physics, University of Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela, Spain
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18
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Korshin DE, Kashapov RR, Murtazina LI, Mukhitova RK, Kharlamov SV, Latypov SK, Ryzhkina IS, Ziganshina AY, Konovalov AI. Self-assembly of an aminoalkylated resorcinarene in aqueous media: host–guest properties. NEW J CHEM 2009. [DOI: 10.1039/b9nj00457b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Brand T, Nolis P, Richter S, Berger S. NMR study of the gelation of a designed gelator. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:545-549. [PMID: 18324740 DOI: 10.1002/mrc.2211] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The gelation of a designed gelator was investigated by different NMR methods, which showed a clear thermal hysteresis. Two very simple approaches for the NMR determination of the gelation point are suggested. One involves the observation of the NMR integral, and the other records the ratio of the diffusion coefficients between the gelator and the solvent. Differential behavior of the gelator protons are interpreted as a hint that a part of the gelator molecule might still be flexible as in the dissolved state.
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Affiliation(s)
- Torsten Brand
- Institute of Analytical Chemistry, University of Leipzig, Linnéstrasse 3, D-04103 Leipzig, Germany
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Kharlamov SV, Ziganshina AY, Mukhitova RK, Latypov SK, Konovalov AI. Redox induced translocation of a guest molecule between viologen–resorcinarene and β-cyclodextrin. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.02.098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Richter S. Comparison of Critical Exponents Determined by Rheology and Dynamic Light Scattering on Irreversible and Reversible Gelling Systems. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/masy.200751010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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Richter S. Recent Gelation Studies on Irreversible and Reversible Systems with Dynamic Light Scattering and Rheology - A Concise Summary. MACROMOL CHEM PHYS 2007. [DOI: 10.1002/macp.200700285] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Saalwächter K, Gottlieb M, Liu, Oppermann W. Gelation as Studied by Proton Multiple-Quantum NMR. Macromolecules 2007. [DOI: 10.1021/ma062776b] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kay Saalwächter
- Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Friedemann-Bach-Platz 6, D-06018 Halle, Germany
| | - Moshe Gottlieb
- The Raimund Stadler Minerva Center for Mesoscale Macromolecular Engineering, and Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheeva 84105, Israel
| | - Liu
- Institut für Physikalische Chemie, Technische Universität Clausthal, Arnold-Sommerfeld-Str. 4, D-38678 Clausthal-Zellerfeld
| | - Wilhelm Oppermann
- Institut für Physikalische Chemie, Technische Universität Clausthal, Arnold-Sommerfeld-Str. 4, D-38678 Clausthal-Zellerfeld
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Guerrero-Martínez A, Montoro T, Viñas MH, González-Gaitano G, Tardajos G. Study of the Interaction between a Nonyl Phenyl Ether and β-Cyclodextrin: Declouding Nonionic Surfactant Solutions by Complexation. J Phys Chem B 2007; 111:1368-76. [PMID: 17253736 DOI: 10.1021/jp0658290] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Absorption and fluorescence measurements for aqueous solutions at 298 K containing pentaoxyethylene nonyl phenyl ether (NPE5), in the absence and presence of beta-cyclodextrin (beta-CD), were analyzed to determine the effect of the complexation on the aggregation of the surfactant. For the binary system, the appearance of a new emission band and the presence of an isoemissive point in the emission spectra at the time and frequency domains indicate the formation of an excimer within the micellar core. The addition of beta-CD induces the formation of an inclusion complex strong enough to break the aggregates and avoid the excimer formation. For the ternary system, the increase in fluorescence has been used to assess the binding constants of 1:1 + 2:1 stoichiometries. Static light scattering, 1H NMR diffusion-ordered spectroscopy (DOSY), and two-dimensional rotating-frame Overhauser enhancement spectroscopy (ROESY) experiments were used to characterize the cloud point of NPE5 at 298 K, and to ascertain the effects of complexation on the clouding process. In the presence of beta-CD, the analysis of the 1H NMR spectra and the self-diffusion coefficients reveal the existence of interactions between the beta-CD and the aggregates that increase the cloud-point concentration more than expected. Under conditions of excess of beta-CD, ROE enhancements point to a complex of dominant 2:1 stoichiometry (beta-CD:NPE5) in which the hydrophobic moiety of the surfactant threads two beta-CDs.
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Affiliation(s)
- Andrés Guerrero-Martínez
- Departamento de Química-Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain
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27
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Guerrero-Martínez A, Palafox M, Tardajos G. Unexpected binding mode of gemini surfactants and γ-cyclodextrin: DOSY as a tool for the study of complexation. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.10.091] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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