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Carmona P, Tasici AM, Sande SA, Knudsen KD, Nyström B. Glyceraldehyde as an Efficient Chemical Crosslinker Agent for the Formation of Chitosan Hydrogels. Gels 2021; 7:186. [PMID: 34842656 PMCID: PMC8628775 DOI: 10.3390/gels7040186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/20/2021] [Accepted: 10/26/2021] [Indexed: 12/05/2022] Open
Abstract
The rheological changes that occur during the chemical gelation of semidilute solutions of chitosan in the presence of the low-toxicity agent glyceraldehyde (GCA) are presented and discussed in detail. The entanglement concentration for chitosan solutions was found to be approximately 0.2 wt.% and the rheological experiments were carried out on 1 wt.% chitosan solutions with various amounts of GCA at different temperatures (25 °C and 40 °C) and pH values (4.8 and 5.8). High crosslinker concentration, as well as elevated temperature and pH close to the pKa value (pH ≈ 6.3-7) of chitosan are three parameters that all accelerate the gelation process. These conditions also promote a faster solid-like response of the gel-network in the post-gel region after long curing times. The mesh size of the gel-network after a very long (18 h) curing time was found to contract with increasing level of crosslinker addition and elevated temperature. The gelation of chitosan in the presence of other chemical crosslinker agents (glutaraldehyde and genipin) is discussed and a comparison with GCA is made. Small angle neutron scattering (SANS) results reveal structural changes between chitosan solutions, incipient gels, and mature gels.
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Affiliation(s)
- Pierre Carmona
- Department of Chemistry, University of Oslo, N-0315 Oslo, Norway;
- Department of Physics, Division of Nano-and BioPhysics, Chalmers University of Technology, Fysikgränd 3, 412 96 Gothenburg, Sweden
| | - Anca M. Tasici
- Department of Pharmacy, Section for Pharmaceutics and Social Pharmacy, University of Oslo, N-0316 Oslo, Norway; (A.M.T.); (S.A.S.)
| | - Sverre A. Sande
- Department of Pharmacy, Section for Pharmaceutics and Social Pharmacy, University of Oslo, N-0316 Oslo, Norway; (A.M.T.); (S.A.S.)
| | | | - Bo Nyström
- Department of Chemistry, University of Oslo, N-0315 Oslo, Norway;
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Ditta LA, Bulone D, Biagio PLS, Marino R, Giacomazza D, Lapasin R. The degree of compactness of the incipient High Methoxyl Pectin networks. A rheological insight at the sol-gel transition. Int J Biol Macromol 2020; 158:985-993. [PMID: 32387608 DOI: 10.1016/j.ijbiomac.2020.05.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/26/2020] [Accepted: 05/03/2020] [Indexed: 11/24/2022]
Abstract
Fractal analysis can be properly applied to complex structures, like physical and chemical networks formed by particles or polymers, when they exhibit self-similarity over an extended range of length scales and, hence, can be profitably used not only for their morphological characterization but also for individuating possible relationships between morphology and mechanisms of aggregation and crosslinking, as well as between morphology and physical properties. Several experimental methods are available to determine the fractal dimension of gel networks, including various scattering techniques and microscopies, permeability measurements and rheology. The present study regards the self-assembly kinetics of High Methoxyl Pectin (HMP) solutions with different pectin and sucrose concentrations investigated by rheological measurements to highlight the effects of pectin and sucrose concentrations on the gel point and to evaluate the degree of compactness of the incipient gel networks through an interpretation of the viscoelastic response at the sol-gel transition.
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Affiliation(s)
- Lorena Anna Ditta
- Consiglio Nazionale delle Ricerche - Istituto di Biofisica (Palermo Unit), via U. La Malfa, 153, I-90146 Palermo, Italy.
| | - Donatella Bulone
- Consiglio Nazionale delle Ricerche - Istituto di Biofisica (Palermo Unit), via U. La Malfa, 153, I-90146 Palermo, Italy.
| | - Pier Luigi San Biagio
- Consiglio Nazionale delle Ricerche - Istituto di Biofisica (Palermo Unit), via U. La Malfa, 153, I-90146 Palermo, Italy.
| | - Rosamaria Marino
- Silvateam Food Ingredients s.r.l., - Via M. Polo, 72, I-87036 Rende, CS, Italy.
| | - Daniela Giacomazza
- Consiglio Nazionale delle Ricerche - Istituto di Biofisica (Palermo Unit), via U. La Malfa, 153, I-90146 Palermo, Italy.
| | - Romano Lapasin
- Università di Trieste, Dipartimento di Ingegneria e Architettura, Piazzale Europa, I-34127 Trieste, Italy.
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Wang X, Guan J, Zhuang X, Li Z, Huang S, Yang J, Liu C, Li F, Tian F, Wu J, Shu Z. Exploration of Blood Coagulation of N-Alkyl Chitosan Nanofiber Membrane in Vitro. Biomacromolecules 2018; 19:731-739. [PMID: 29309730 DOI: 10.1021/acs.biomac.7b01492] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
N-Alkylated chitosan (NACS) may improve the blood clotting efficiency of chitosan (CS). To study its blood coagulation capability, a series of NACSs with various carbon chain lengths and degrees of substitution (DS) of alkyl groups were synthesized and characterized by FTIR, NMR, elemental analysis, and X-ray diffraction (XRD). The corresponding NACS nanofiber membranes (NACS-NM) were subsequently fabricated by electronic spinning technique. SEM, XRD, DSC, surface area, porosity, contact angle, blood absorption, and mechanical properties were used to characterize the CS-NM/NACS-NM. Moreover, cytotoxicity, coagulation, activated partial thromboplastin time, plasma prothrombin time, thrombin time, and platelet aggregation tests were performed to evaluate the biocompatibility and blood coagulation properties of NACS-NM. The results showed that NACS-NM was not cytotoxic. NACS-NM with DS of 19.25% for N-hexane CS (CS6b), 17.87% for N-dodecane CS (CS12b), and 8.97% for N-octadecane CS (CS18a) exhibited good blood clotting performance. Moreover, NACS-NMs favored the activation of coagulation factors and platelets. In addition, intracellular Ca2+ was not related to platelet activation. The above results suggested that NACS-NM would be an effective hemostatic agent.
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Affiliation(s)
- Xiaoyan Wang
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China.,Department of Textile , Tianjin Polytechnic University , No. 399 Binshui West Road , Xiqing District, Tianjin 300387 , China
| | - Jing Guan
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Xupin Zhuang
- Department of Textile , Tianjin Polytechnic University , No. 399 Binshui West Road , Xiqing District, Tianjin 300387 , China
| | - Zhihong Li
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Shujie Huang
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Jian Yang
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Changjun Liu
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Fan Li
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Feng Tian
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Jimin Wu
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
| | - Zhan Shu
- Key laboratory of Medical Equipment , Academy of Military Medical Sciences , No. 106 Wandong Road , Hedong District, Tianjin 300161 , China
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Impact of molecular weight on the formation of electrosprayed chitosan microcapsules as delivery vehicles for bioactive compounds. Carbohydr Polym 2016; 150:121-30. [DOI: 10.1016/j.carbpol.2016.05.012] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 05/02/2016] [Accepted: 05/05/2016] [Indexed: 12/12/2022]
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Calejo MT, Kjøniksen AL, Maleki A, Nyström B, Sande SA. Microparticles based on hydrophobically modified chitosan as drug carriers. J Appl Polym Sci 2013. [DOI: 10.1002/app.40055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Maria Teresa Calejo
- Department of Pharmaceutics; School of Pharmacy; University of Oslo; Blindern N-0316 Oslo Norway
| | - Anna-Lena Kjøniksen
- Department of Pharmaceutics; School of Pharmacy; University of Oslo; Blindern N-0316 Oslo Norway
- Faculty of Engineering; Østfold University College; 1757 Halden Norway
| | - Atoosa Maleki
- Department of Chemistry; University of Oslo; N-0315 Oslo Norway
| | - Bo Nyström
- Department of Chemistry; University of Oslo; N-0315 Oslo Norway
| | - Sverre Arne Sande
- Department of Pharmaceutics; School of Pharmacy; University of Oslo; Blindern N-0316 Oslo Norway
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Zahedi P, De Souza R, Piquette-Miller M, Allen C. Chitosan–phospholipid blend for sustained and localized delivery of docetaxel to the peritoneal cavity. Int J Pharm 2009; 377:76-84. [DOI: 10.1016/j.ijpharm.2009.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 05/03/2009] [Indexed: 11/28/2022]
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Schneider HJ, Kato K, Strongin RM. Chemomechanical Polymers as Sensors and Actuators for Biological and Medicinal Applications. SENSORS 2007; 7:1578-1611. [PMID: 19606275 PMCID: PMC3814870 DOI: 10.3390/s7081578] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Changes in the chemical environment can trigger large motions in chemomechanical polymers. The unique feature of such intelligent materials, mostly in the form of hydrogels, is therefore, that they serve as sensors and actuators at the same time, and do not require any measuring devices, transducers or power supplies. Until recently the most often used of these materials responded to changes in pH. Chemists are now increasingly using supramolecular recognition sites in materials, which are covalently bound to the polymer backbone. This allows one to use a nearly unlimited variety of guest (or effector) compounds in the environment for a selective response by automatically triggered size changes. This is illustrated with non-covalent interactions of effectors comprising of metal ions, isomeric organic compounds, including enantiomers, nucleotides, aminoacids, and peptides. Two different effector molecules can induce motions as functions of their concentration, thus representing a logical AND gate. This concept is particularly fruitful with effector compounds such as peptides, which only trigger size changes if, e.g. copper ions are present in the surroundings. Another principle relies on the fast formation of covalent bonds between an effector and the chemomechanical polymer. The most promising application is the selective interaction of covalently fixed boronic acid residues with glucose, which renders itself not only for sensing, but eventually also for delivery of drugs such as insulin. The speed of the responses can significantly increase by increasing the surface to volume ratio of the polymer particles. Of particular interest is the sensitivity increase which can be reached by downsizing the particle volume.
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Affiliation(s)
- Hans-Jörg Schneider
- FR Organische Chemie der Universität des Saarlandes, D-66041 Saarbrücken, Germany
- Authors to whom correspondence should be addressed; E-mails: ;
| | - Kazuaki Kato
- FR Organische Chemie der Universität des Saarlandes, D-66041 Saarbrücken, Germany
- Department of Advanced Material Science, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan; E-mail:
| | - Robert M. Strongin
- Department of Chemistry, Portland State University, Portland, OR, 97201, USA
- Authors to whom correspondence should be addressed; E-mails: ;
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Saxena A, Shahi V, Kumar A. Thermodynamic study of functionally modified chitosan and its blends in aqueous media at 298.15 K. J Mol Liq 2007. [DOI: 10.1016/j.molliq.2006.10.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Zhu C, Lee JH, Raghavan SR, Payne GF. Bioinspired vesicle restraint and mobilization using a biopolymer scaffold. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:2951-5. [PMID: 16548539 DOI: 10.1021/la053475i] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Biology employs vesicles to package molecules (e.g., neurotransmitters) for their targeted delivery in response to specific spatiotemporal stimuli. Biology is also capable of employing localized stimuli to exert an additional control on vesicle trafficking; intact vesicles can be restrained (or mobilized) by association with (or release from) a cytoskeletal scaffold. We mimic these capabilities by tethering vesicles to a biopolymer scaffold that can undergo (i) stimuli-responsive network formation (for vesicle restraint) and (ii) enzyme-catalyzed network cleavage (for vesicle mobilization). Specifically, we use the aminopolysaccharide chitosan as our scaffold and graft a small number of hydrophobic moieties onto its backbone. These grafted hydrophobes can insert into the bilayer to tether vesicles to the scaffold. Under acidic conditions, the vesicles are not restrained by the hydrophobically modified chitosan (hm-chitosan) because this scaffold is soluble. Increasing the pH to neutral or basic conditions allows chitosan to form interpolymer associations that yield a strong, insoluble restraining network. Enzymatic hydrolysis of this scaffold by chitosanase cleaves the network and mobilizes intact vesicles. Potentially, this approach will provide a controllable means to store and liberate vesicle-based reagents/therapeutics for microfluidic/medical applications.
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Affiliation(s)
- Chao Zhu
- Center for Biosystems Research, University of Maryland Biotechnology Institute, College Park, Maryland 20742, USA
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Cho J, Heuzey MC, Bégin A, Carreau PJ. Physical Gelation of Chitosan in the Presence of β-Glycerophosphate: The Effect of Temperature. Biomacromolecules 2005; 6:3267-75. [PMID: 16283755 DOI: 10.1021/bm050313s] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
When adding beta-glycerophosphate (beta-GP), a weak base, to chitosan aqueous solutions, the polymer remains in solution at neutral pH and room temperature, while homogeneous gelation of this system can be triggered upon heating. It is therefore one of the rare true physical chitosan hydrogels. In this study, physicochemical and rheological properties of chitosan solutions in the presence of acetic acid and beta-GP were investigated as a function of temperature in order to gain a better understanding of the gelation mechanisms. The gel structure formed at high temperature was only partially thermoreversible upon cooling to 5 degrees C because of the existence of remaining associations, confirmed by the spontaneous recovery of the gel after breakup at low temperature. Increasing temperature had no effect on the pH values of this system, while conductivity (and calculated ionic strength) increased. Values from the pH measurements were used to estimate the degree of protonation of each species as a function of temperature. The decreasing ratio of -NH3+ in chitosan and -OPO(O-)2 in beta-GP suggested reduced chitosan solubility along with a diminution of ionic interactions such as ionic bridging with increasing temperature. On the other hand, the increased ionic strength as a function of temperature, in the presence of beta-GP, enhanced screening of electrostatic repulsion and increased hydrophobic effect, resulting in favorable conditions for gel formation. Therefore, our study suggests that hydrophobic interactions and reduced solubility are the main driving force for chitosan gelation at high temperature in the presence of beta-GP.
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Affiliation(s)
- Jaepyoung Cho
- CREPEC, Department of Chemical Engineering, Ecole Polytechnique, P.O. Box 6079, Station Centre-Ville, Montreal, QC, H3C 3A7, Canada
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Rinaudo M, Auzely R, Vallin C, Mullagaliev I. Specific Interactions in Modified Chitosan Systems. Biomacromolecules 2005; 6:2396-407. [PMID: 16153074 DOI: 10.1021/bm0580025] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper concerns the bulk and interfacial properties of a series of alkylated chitosans having different alkyl chain lengths grafted randomly along the main chitosan chain. Chitosan has a low degree of acetylation (5%); on chitosan derivatives, the role of the degree of grafting and of length of the alkyl chains are examined. The optimum alkyl chain length is C12 and the degree of grafting 5% to get physical gelation based on the formation of hydrophobic domains. The cross-linking is essentially controlled by the salt concentration: it is shown that 0.025 M AcONa is needed to screen electrostatic interchain repulsions. Hydrophobic interactions produce highly non-Newtonian behavior with large thinning behavior; this behavior is suppressed in the presence of cyclodextrins able to cap the hydrophobic alkyl chains. The interfacial properties of the chitosan derivatives were tested for the air/aqueous solution interfaces. Specifically, the role of their structure on the kinetic of film formation was examined showing that excess of external salt favors the stabilization of the interfacial film. The derivatives with a higher degree of substitution and longer alkyl chains are more efficient and give a higher elastic modulus compared to the model surfactant as a result of the chain properties.
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Affiliation(s)
- M Rinaudo
- Centre de recherche sur les Macromolécules Végétales, CNRS, Joseph Fourier University, BP 53, 38041 Grenoble Cedex 9, France
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Autoassociative natural polymer derivatives: the alkylchitosans. Rheological behaviour and temperature stability. POLYMER 2004. [DOI: 10.1016/j.polymer.2004.03.032] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Berger J, Reist M, Mayer JM, Felt O, Gurny R. Structure and interactions in chitosan hydrogels formed by complexation or aggregation for biomedical applications. Eur J Pharm Biopharm 2004; 57:35-52. [PMID: 14729079 DOI: 10.1016/s0939-6411(03)00160-7] [Citation(s) in RCA: 570] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The aim of this review was to provide a detailed overview of physical chitosan hydrogels and related networks formed by aggregation or complexation, which are intended for biomedical applications. The structural basis of these systems is discussed with particular emphasis on the network-forming interactions, the principles governing their formation and their physicochemical properties. An earlier review discussing crosslinked chitosan hydrogels highlighted the potential negative influence on biocompatibility of covalent crosslinkers and emphasised the need for alternative hydrogel systems. A possible means to avoid the use of covalent crosslinkers is to prepare physical chitosan hydrogels by direct interactions between polymeric chains, i.e. by complexation, e.g. polyelectrolyte complexes (PEC) and chitosan/poly (vinyl alcohol) (PVA) complexes, or by aggregation, e.g. grafted chitosan hydrogels. PEC exhibit a higher swelling sensitivity towards pH changes compared to covalently crosslinked chitosan hydrogels, which extends their potential application. Certain complexed polymers, such as glycosaminoglycans, can exhibit interesting intrinsic properties. Since PEC are formed by non-permanent networks, dissolution can occur. Chitosan/PVA complexes represent an interesting alternative for preparing biocompatible drug delivery systems if pH-controlled release is n/ot required. Grafted chitosan hydrogels are more complex to prepare and do not always improve biocompatibility compared to covalently crosslinked hydrogels, but can enhance certain intrinsic properties of chitosan such as bacteriostatic and wound-healing activity.
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Affiliation(s)
- J Berger
- School of Pharmacy, University of Lausanne, Lausanne, Switzerland
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Yim KS, Fuller GG. Influence of phase transition and photoisomerization on interfacial rheology. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 67:041601. [PMID: 12786367 DOI: 10.1103/physreve.67.041601] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2002] [Revised: 12/05/2002] [Indexed: 05/24/2023]
Abstract
This paper presents the shear responses and interfacial rheology of photosensitive monolayers. Langmuir films of a fatty acid containing an azobenzene moiety that can undergo trans-cis photoisomerization have been investigated for their structural and dynamical properties. The cis conformation produces a structureless, Newtonian film that cannot be oriented by surface flows. Transforming the molecule to the trans configuration produces a well-packed film that responds to flow with an anisotropic and non-Newtonian character. The trans state supports two separate phases, a low-pressure phase where the azobenzene group is free to rotate, and a high-pressure phase where this moiety is frozen in place.
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Affiliation(s)
- Kang Sub Yim
- Department of Chemical Engineering, Stanford University, California 94305, USA
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Desbrieres J. Viscosity of semiflexible chitosan solutions: influence of concentration, temperature, and role of intermolecular interactions. Biomacromolecules 2002; 3:342-9. [PMID: 11888321 DOI: 10.1021/bm010151+] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The influence of polymer concentration and temperature on the rheological behavior of chitosan solution was studied. The threshold concentrations for the different viscometric regimes were determined and the different power laws exponents were calculated and compared with those predicted from models. Different observations and the high values of these exponents within the high concentration region lead to consideration of the presence of intermolecular interactions as soon as the polymer concentration is larger than the overlap concentration. The activation energy was determined as a function of the polymer concentration, and its evolution was compared with theoretical predictions. A gel-sol transition was demonstrated at high concentrations.
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Affiliation(s)
- J Desbrieres
- CERMAV (CNRS), affiliated with the Joseph Fourier University, Grenoble, BP 53, 38041 Grenoble Cedex 9, France
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Kopperud HBM, Hansen FK. Surface Tension and Surface Dilatational Elasticity of Associating Hydrophobically Modified Polyacrylamides in Aqueous Solutions. Macromolecules 2001. [DOI: 10.1021/ma002079y] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Finn Knut Hansen
- Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway
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Ng W, Tam K, Jenkins R. Rheological properties of methacrylic acid/ethyl acrylate co-polymer: comparison between an unmodified and hydrophobically modified system. POLYMER 2001. [DOI: 10.1016/s0032-3861(00)00280-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Zhou MH, Cho WJ. High oil-absorptive composites based on 4-tert-butylstyrene-EPDM-divinylbenzene graft polymer. POLYM INT 2001. [DOI: 10.1002/pi.762] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chen T, Kumar G, Harris MT, Smith PJ, Payne GF. Enzymatic grafting of hexyloxyphenol onto chitosan to alter surface and rheological properties. Biotechnol Bioeng 2000; 70:564-73. [PMID: 11042553 DOI: 10.1002/1097-0290(20001205)70:5<564::aid-bit11>3.0.co;2-w] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An enzymatic method to graft hexyloxyphenol onto the biopolymer chitosan was studied. The method employs tyrosinase to convert the phenol into a reactive o-quinone, which undergoes subsequent nonenzymatic reaction with chitosan. Reactions were conducted under heterogeneous conditions using chitosan films and also under homogeneous conditions using aqueous methanolic mixtures capable of dissolving both hexyloxyphenol and chitosan. Tyrosinase was shown to catalyze the oxidation of hexyloxyphenol in such aqueous methanolic solutions. Chemical evidence for covalent grafting onto chitosan was provided by three independent spectroscopic approaches. Specifically, enzymatic modification resulted in (1) the appearance of broad absorbance in the 350-nm region of the UV/vis spectra for chitosan films; (2) changes in the NH bending and stretching regions of chitosan's IR spectra; and (3) a base-soluble material with (1)H-NMR signals characteristic of both chitosan and the alkyl groups of hexyloxyphenol. Hexyloxyphenol modification resulted in dramatic changes in chitosan's functional properties. On the basis of contact angle measurements, heterogeneous modification of a chitosan film yielded a hydrophobic surface. Homogeneously modified chitosan offered rheological properties characteristic of associating water-soluble polymers.
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Affiliation(s)
- T Chen
- Center for Agricultural Biotechnology, 5115 Plant Sciences Building, University of Maryland, College Park, Maryland 20742, USA
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Dai S, Tam KC, Jenkins RD. Microstructure of Dilute Hydrophobically Modified Alkali Soluble Emulsion in Aqueous Salt Solution. Macromolecules 1999. [DOI: 10.1021/ma990887n] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. Dai
- School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Republic of Singapore, and Union Carbide Asia Pacific Inc., Technical Center, 16 Science Park Drive, The Pasteur, Singapore 118227, Republic of Singapore
| | - K. C. Tam
- School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Republic of Singapore, and Union Carbide Asia Pacific Inc., Technical Center, 16 Science Park Drive, The Pasteur, Singapore 118227, Republic of Singapore
| | - R. D. Jenkins
- School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Republic of Singapore, and Union Carbide Asia Pacific Inc., Technical Center, 16 Science Park Drive, The Pasteur, Singapore 118227, Republic of Singapore
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Ostrovskii D, Jacobsson P, Nyström B, Marstokk O, Kopperud HBM. Raman Spectroscopic Characterization of Association and Thermoreversible Gelation in Aqueous Systems of Poly(N-acetamidoacrylamide). Macromolecules 1999. [DOI: 10.1021/ma9904969] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. Ostrovskii
- Department of Experimental Physics, Chalmers University of Technology, SE−41296 Göteborg, Sweden; Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway; and Jotun A/S, P.O. Box 2021, N-3235 Sandefjord, Norway
| | - P. Jacobsson
- Department of Experimental Physics, Chalmers University of Technology, SE−41296 Göteborg, Sweden; Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway; and Jotun A/S, P.O. Box 2021, N-3235 Sandefjord, Norway
| | - B. Nyström
- Department of Experimental Physics, Chalmers University of Technology, SE−41296 Göteborg, Sweden; Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway; and Jotun A/S, P.O. Box 2021, N-3235 Sandefjord, Norway
| | - O. Marstokk
- Department of Experimental Physics, Chalmers University of Technology, SE−41296 Göteborg, Sweden; Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway; and Jotun A/S, P.O. Box 2021, N-3235 Sandefjord, Norway
| | - H. B. M. Kopperud
- Department of Experimental Physics, Chalmers University of Technology, SE−41296 Göteborg, Sweden; Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway; and Jotun A/S, P.O. Box 2021, N-3235 Sandefjord, Norway
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Nyström B, Kjøniksen AL, Iversen C. Characterization of association phenomena in aqueous systems of chitosan of different hydrophobicity1Part of this paper was presented at the conference on `Associating Polymer', Fontevraud, France, November 1997.1. Adv Colloid Interface Sci 1999. [DOI: 10.1016/s0001-8686(98)00069-4] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kjøniksen AL, Iversen C, Nyström B, Nakken T, Palmgren O. Light Scattering Study of Semidilute Aqueous Systems of Chitosan and Hydrophobically Modified Chitosans. Macromolecules 1998. [DOI: 10.1021/ma980825h] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna-Lena Kjøniksen
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway, and Norsk Hydro, Research Centre Porsgrunn, Department of Polymer and Surface Chemistry, P.O. Box 2560, N-3901, Porsgrunn, Norway
| | - Christian Iversen
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway, and Norsk Hydro, Research Centre Porsgrunn, Department of Polymer and Surface Chemistry, P.O. Box 2560, N-3901, Porsgrunn, Norway
| | - Bo Nyström
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway, and Norsk Hydro, Research Centre Porsgrunn, Department of Polymer and Surface Chemistry, P.O. Box 2560, N-3901, Porsgrunn, Norway
| | - Torgeir Nakken
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway, and Norsk Hydro, Research Centre Porsgrunn, Department of Polymer and Surface Chemistry, P.O. Box 2560, N-3901, Porsgrunn, Norway
| | - Odd Palmgren
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway, and Norsk Hydro, Research Centre Porsgrunn, Department of Polymer and Surface Chemistry, P.O. Box 2560, N-3901, Porsgrunn, Norway
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