1
|
Lysenkov E, Klepko V, Bulavin L, Lebovka N. Physico-Chemical Properties of Laponite®/Polyethylene-oxide Based Composites. CHEM REC 2024; 24:e202300166. [PMID: 37387571 DOI: 10.1002/tcr.202300166] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 06/05/2023] [Indexed: 07/01/2023]
Abstract
This review aims to provide a literature overview as well as the authors' personal account to the studies of Laponite® (Lap)/Polyethylene-oxide (PEO) based composite materials and their applications. These composites can be prepared over a wide range of their mutual concentrations, they are highly water soluble, and have many useful physico-chemical properties. To the readers' convenience, the contents are subdivided into different sections, related with consideration of PEO properties and its solubility in water, behavior of Lap systems(structure of Lap-platelets, properties of aqueous dispersions of Lap and aging effects in them), analyzing ofproperties LAP/PEO systems, Lap platelets-PEO interactions, adsorption mechanisms, aging effects, aggregation and electrokinetic properties. The different applications of Lap/PEO composites are reviewed. These applications include Lap/PEO based electrolytes for lithium polymer batteries, electrospun nanofibers, environmental, biomedical and biotechnology engineering. Both Lap and PEO are highly biocompatible with living systems and they are non-toxic, non-yellowing, and non-inflammable. Medical applications of Lap/PEO composites in bio-sensing, tissue engineering, drug delivery, cell proliferation, and wound dressings are also discussed.
Collapse
Affiliation(s)
- Eduard Lysenkov
- Petro Mohyla Black Sea National University, Mykolaiv, Ukraine
| | - Valery Klepko
- Institute of Macromolecular Chemistry, Kyiv, Ukraine
| | - Leonid Bulavin
- Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Nikolai Lebovka
- Institute of Biocolloidal Chemistry named after F. D. Ovcharenko, Kyiv, Ukraine
| |
Collapse
|
2
|
Morariu S, Brunchi CE, Honciuc M, Iftime MM. Development of Hybrid Materials Based on Chitosan, Poly(Ethylene Glycol) and Laponite ® RD: Effect of Clay Concentration. Polymers (Basel) 2023; 15:polym15040841. [PMID: 36850125 PMCID: PMC9959284 DOI: 10.3390/polym15040841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
In the context of increasing interest in biomaterials with applicability in cosmetics and medicine, this research aims to obtain and characterize some hybrid materials based on chitosan (CS) (antibacterial, biocompatible, and biodegradable), poly(ethylene glycol) (PEG) (non-toxic and prevents the adsorption of protein and cell) and Laponite® RD (Lap) (bioactive). The rheological properties of the starting dispersions were investigated and discussed related to the interactions developed between components. All samples exhibited gel-like properties, and the storage modulus of CS/PEG dispersion increased from 6.6 Pa to 657.7 Pa by adding 2.5% Lap. Structural and morphological characterization of the films, prepared by solution casting method, was performed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and polarized light microscopy (POM). These analyses proved the incorporation of Lap into CS/PEG films and revealed the morphological changes of the films by the addition of clay. Thereby, at the highest Lap concentration (43.8%), the "house of cards" structure formed by Lap platelets, which incorporate chitosan chains, as evidenced by SEM and POM. Two stages of degradation between 200 °C and 410 °C were evidenced for the films with Lap concentration higher than 38.5%, explained by the existence of a clay-rich phase (given by the clay network) and chitosan-rich one (due to the intercalation of chitosan in the clay network). CS/PEG film with 43.8% Lap showed the highest swelling degree of 240.7%. The analysis of the obtained results led to the conclusion that the addition of clay to the CS/PEG films increases their stability in water and gives them greater thermal stability.
Collapse
|
3
|
El Rifaii K, Wensink HH, Bizien T, Gabriel JCP, Michot L, Davidson P. Destabilization of the Nematic Phase of Clay Nanosheet Suspensions by Polymer Adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12563-12571. [PMID: 33050693 DOI: 10.1021/acs.langmuir.0c02084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Complex aqueous mixtures comprised of swelling clays and hydrosoluble polymers naturally occur in soils and play a major role in pedogenesis. They are also very often used for formulating oil-well drilling fluids, paints, and personal-care products. The suspensions of some natural clays, thanks to their large nanoparticle aspect ratio, spontaneously form nematic liquid-crystalline phases where the particles align parallel to each other, which affects their flow properties. We observed that adding small amounts of hydrosoluble polymers to these clay suspensions destabilizes the nematic phase with respect to the isotropic (disordered) phase. The polymers that we used (poly(ethylene oxide) and dextran) were too small to adopt particle-bridging conformations and small-angle X-ray scattering experiments showed that the structure of the nematic phase is not altered by polymer doping. However, the adsorption isotherm shows that the macromolecules adsorb onto the clay nanosheets, effectively coating them with a polymer layer. Our extension of Onsager's theory for polymer-coated platelets properly captures the experimental phase diagram and shows how the nematic phase destabilization can be due to the polymer adsorbing more on the platelet faces than at the rim. Because the flow properties of the nematic phase are very different from those of the isotropic phase, the presence or absence of the former phase is an important factor to be determined and considered to explain the rheological behavior of these complex systems.
Collapse
Affiliation(s)
- Karin El Rifaii
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Henricus H Wensink
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Thomas Bizien
- SWING beamline, SOLEIL Synchrotron, 91192 Gif-sur-Yvette, France
| | | | - Laurent Michot
- Laboratory of Physical Chemistry of Electrolytes and Interfacial Nanosystems (PHENIX), Sorbonne Universite', CNRS, 75005 Paris, France
| | - Patrick Davidson
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
| |
Collapse
|
4
|
Le Coeur C, Lorthioir C, Feoktystov A, Wu B, Volet G, Amiel C. Laponite/poly(2-methyl-2-oxazoline) hydrogels: Interplay between local structure and rheological behaviour. J Colloid Interface Sci 2020; 582:149-158. [PMID: 32814221 DOI: 10.1016/j.jcis.2020.07.068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 11/08/2022]
Abstract
HYPOTHESIS Dispersions of Laponite in water may form gels, the rheological properties of which being possibly tuned by the addition of polymer chains. Laponite-based hydrogels with poly(ethylene oxide) (PEO) were the most widely investigated systems and the PEO chains were then found to reduce the elastic modulus. EXPERIMENTS Here, hydrogels based on Laponite and poly(2-methyl-2-oxazoline) (POXA) were considered. The adsorption behavior and the local structures within these nanocomposite gels were investigated by small-angle neutron scattering and NMR. The same materials were macroscopically characterized using rheology. FINDINGS An original evolution of the storage modulus G' with the POXA concentration is evidenced compared to Laponite/PEO hydrogels. At low POXA concentrations, a continuous reduction of G' is observed upon increasing the polymer content, as with PEO, due to the screening of electrostatic interactions between the clay platelets. However, above a critical value of the POXA concentration, G' increases with the polymer content. This difference with PEO-based hydrogels is correlated to the stronger affinity of POXA chains for the clay surfaces, which results in the reduction of the inhomogeneities for the Laponite disks within the gels. Steric repulsions would then counterbalance the effect of electrostatic repulsions and lead to the strengthening of the POXA-based hydrogels.
Collapse
Affiliation(s)
- C Le Coeur
- Université Paris Est Creteil, CNRS, Institut Chimie et Matériaux Paris Est, 2 Rue Henri Dunant, 94320 Thiais, France; Laboratoire Léon Brillouin, CEA-CNRS (UMR-12), CEA Saclay, Université Paris-Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | - C Lorthioir
- Sorbonne Université, CNRS, Collège de France, Laboratoire de Chimie de la Matière Condensée de Paris, 4 Place Jussieu, 75005 Paris, France.
| | - A Feoktystov
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS at Heinz Maier-Leibnitz Zentrum MLZ, Lichtenbergstraße 1, 85748 Garching, Germany.
| | - B Wu
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS at Heinz Maier-Leibnitz Zentrum MLZ, Lichtenbergstraße 1, 85748 Garching, Germany.
| | - G Volet
- Université Paris Est Creteil, CNRS, Institut Chimie et Matériaux Paris Est, 2 Rue Henri Dunant, 94320 Thiais, France; Université d'Evry Val d'Essonne, Rue du Père Jarlan, 91025 Evry Cedex, France.
| | - C Amiel
- Université Paris Est Creteil, CNRS, Institut Chimie et Matériaux Paris Est, 2 Rue Henri Dunant, 94320 Thiais, France.
| |
Collapse
|
5
|
Manilo MV, Lebovka NI, Barany S. Electrokinetic Behavior of Laponite RD in Aqueous Suspensions Containing Poly(ethylene oxide) and Cetyltrimethylammonium Bromide. J Phys Chem B 2020; 124:4372-4378. [PMID: 32364739 DOI: 10.1021/acs.jpcb.0c02782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The aqueous suspensions of Laponite RD (Lap) platelets demonstrate rich phase diagrams. Both poly(ethylene oxide) (PEO) and cetyltrimethylammonium bromide (CTAB) molecules competitively adsorb on the surface of Lap, and strong interactions between PEO and CTAB exist. The stability of ternary systems Lap + PEO + CTAB can be finely regulated by changing the balance of these interactions. The electrokinetic technique was used to study 0.065 and 2% wt Lap suspensions in the presence of different amounts of PEO of various molecular masses Mw (400-20,000 g/mol) and CTAB (0-1 mM). For 0.065% wt Lap suspension, the additives of PEO did not affect the position of the isoelectric point (IEP), but the impact of PEO in the regions below or above the IEP was significant, especially for a large Mw. The observed effects were explained, accounting the model for the adsorption of PEO in the form of loops and tails as well as for the changes in the packing balance of CTAB and PEO on the surface of Lap. For 2% wt suspension, the strong effects of Mw on the ζ-potential and aggregation of particles were explained by screening the repulsive double layers by PEO chains, by bridging the Lap particles via PEO molecules, and by the impact of CTAB molecules on the bridging between Lap aggregates.
Collapse
Affiliation(s)
- Maryna V Manilo
- Research Institute of Applied Earth Sciences and MTA-ME Materials Science Research Group, University of Miskolc 3515, Miskolc, Hungary.,F.D. Ovcharenko Institute of Biocolloidal Chemistry, NAS of Ukraine, 42, Vernadsky Avenue, Kyiv 03142, Ukraine
| | - Nikolai I Lebovka
- F.D. Ovcharenko Institute of Biocolloidal Chemistry, NAS of Ukraine, 42, Vernadsky Avenue, Kyiv 03142, Ukraine
| | - Sandor Barany
- Research Institute of Applied Earth Sciences and MTA-ME Materials Science Research Group, University of Miskolc 3515, Miskolc, Hungary
| |
Collapse
|
6
|
Versatile poly(vinyl alcohol)/clay physical hydrogels with tailorable structure as potential candidates for wound healing applications. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 109:110395. [DOI: 10.1016/j.msec.2019.110395] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/20/2019] [Accepted: 11/04/2019] [Indexed: 01/07/2023]
|
7
|
Gagliano Candela R, Maggi F, Lazzara G, Rosselli S, Bruno M. The Essential Oil of Thymbra capitata and its Application as A Biocide on Stone and Derived Surfaces. PLANTS 2019; 8:plants8090300. [PMID: 31450558 PMCID: PMC6784118 DOI: 10.3390/plants8090300] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/20/2019] [Accepted: 08/22/2019] [Indexed: 11/16/2022]
Abstract
Many chemicals used nowadays for the preservation of cultural heritage pose a risk to both human health and the environment. Thus, it is desirable to find new and eco-friendly biocides that can replace the synthetic ones. In this regard, plant essential oils represent effective alternatives to synthetic substances for the preservation of historical monuments. Thymbra capitata (syn. Thymus capitatus) is a medicinal and aromatic plant growing in the Mediterranean area and endowed with important pharmacological properties related to its essential oil. Among them, the antimicrobial ones make the T. capitata essential oil an ideal candidate for industrial applications; for instance, as biocide for the inhibition and elimination of biological patinas of cyanobacteria and green algae on historical monuments. In the present work, we studied the chemical composition of the essential oil from T. capitata growing in Malta by gas chromatography-mass spectrometry (GC/MS). The major volatile component is the phenolic monoterpene carvacrol (73.2%), which is capable of damaging the cytoplasmic membrane and to interfere both in the growth curve and in the invasive capacity, though the contribution of minor components γ-terpinene and p-cymene cannot be disregarded. For the oil application on the stone surface, Pickering emulsions systems were prepared with an essential oil/water 1:3 mass ratio stabilized with kaolinite at 4 mass% in the presence of Laponite®; this allowed to limit the fast volatility of the oil and guaranteed a better application and an easier removal from the artefacts attacked by biodeteriogens both indoor and outdoor. This formulation caused the elimination of biodeteriogens from treated surfaces without residuals or films on artworks surface, and the effect was retained up to four months.
Collapse
Affiliation(s)
- Rossella Gagliano Candela
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Viale delle Scienze, I-90128 Palermo, Italy
| | - Filippo Maggi
- School of Pharmacy, University of Camerino, Via Sant'Agostino 1, I-62032 Camerino, Italy.
| | - Giuseppe Lazzara
- Dipartimento di Fisica e Chimica "Emilio Segrè", Università degli Studi di Palermo, Viale delle Scienze, pad. 17, I-90128 Palermo, Italy and Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, INSTM, Via G. Giusti, 9, I-50121 Firenze, Italy
| | - Sergio Rosselli
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Viale delle Scienze, I-90128 Palermo, Italy
| | - Maurizio Bruno
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Viale delle Scienze, I-90128 Palermo, Italy
| |
Collapse
|
8
|
Gao C, Lu Y, Yu C, Tang X. A Comparative Study on the Structure and Properties of α‐amylase‐ and Pullulanase‐Modified Starch‐Polyvinyl Alcohol‐Based Nanocomposite Films. STARCH-STARKE 2019. [DOI: 10.1002/star.201800287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Chengcheng Gao
- College of Food Science and Engineering/Collaborative InnovationCenter for Modern Grain Circulation and Safety/KeyLaboratory of Grains and Oils Quality Control and ProcessingNanjing University of Finance and EconomicsNanjing210023China
| | - Yue Lu
- College of Food Science and Engineering/Collaborative InnovationCenter for Modern Grain Circulation and Safety/KeyLaboratory of Grains and Oils Quality Control and ProcessingNanjing University of Finance and EconomicsNanjing210023China
| | - Chen Yu
- College of Food Science and Engineering/Collaborative InnovationCenter for Modern Grain Circulation and Safety/KeyLaboratory of Grains and Oils Quality Control and ProcessingNanjing University of Finance and EconomicsNanjing210023China
| | - Xiaozhi Tang
- College of Food Science and Engineering/Collaborative InnovationCenter for Modern Grain Circulation and Safety/KeyLaboratory of Grains and Oils Quality Control and ProcessingNanjing University of Finance and EconomicsNanjing210023China
| |
Collapse
|
9
|
Abstract
The review provides an overview of the mesoporous inorganic particles employed as drug delivery systems for controlled and sustained release of drugs. We have classified promising nanomaterials for drug delivery on the basis of their natural or synthetic origin. Nanoclays are available in different morphologies (nanotubes, nanoplates and nanofibers) and they are typically available at low cost from natural resources. The surface chemistry of nanoclays is versatile for targeted modifications to control loading and release properties. Synthetic nanomaterials (imogolite, laponite and mesoporous silica) present the advantages of well-established purity and availability with size features that are finely controlled. Both nanoclays and inorganic synthetic nanoparticles can be functionalized forming organic/inorganic architectures with stimuli-responsive features.
Collapse
|
10
|
Rheology of Laponite-scleroglucan hydrogels. Carbohydr Polym 2017; 168:290-300. [DOI: 10.1016/j.carbpol.2017.03.068] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/15/2017] [Accepted: 03/21/2017] [Indexed: 11/24/2022]
|
11
|
Eslahi N, Simchi A, Mehrjoo M, Shokrgozar MA, Bonakdar S. Hybrid cross-linked hydrogels based on fibrous protein/block copolymers and layered silicate nanoparticles: tunable thermosensitivity, biodegradability and mechanical durability. RSC Adv 2016. [DOI: 10.1039/c6ra08563f] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Schematic representation of LAPONITE® reinforced pluronic/chitosan/keratin nanocomposite hydrogel crosslinked with Genipin.
Collapse
Affiliation(s)
- Niloofar Eslahi
- Department of Materials Science and Engineering
- Sharif University of Technology
- Tehran
- Iran
| | - Abdolreza Simchi
- Department of Materials Science and Engineering
- Sharif University of Technology
- Tehran
- Iran
- Institute for Nanoscience and Nanotechnology
| | - Morteza Mehrjoo
- National Cell Bank of Iran
- Pasteur Institute of Iran
- Tehran
- Iran
| | | | - Shahin Bonakdar
- National Cell Bank of Iran
- Pasteur Institute of Iran
- Tehran
- Iran
| |
Collapse
|
12
|
Kishore S, Chen Y, Ravindra P, Bhatia SR. The effect of particle-scale dynamics on the macroscopic properties of disk-shaped colloid–polymer systems. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.06.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
|
14
|
Zulian L, Augusto de Melo Marques F, Emilitri E, Ruocco G, Ruzicka B. Dual aging behaviour in a clay-polymer dispersion. SOFT MATTER 2014; 10:4513-4521. [PMID: 24817524 DOI: 10.1039/c4sm00172a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Clay-polymer compounds have recently attracted increasing attention due to their intriguing physical properties in colloidal science and their rheological non-trivial behaviour in technological applications. Aqueous solutions of Laponite clay spontaneously age from a liquid up to an arrested state of different nature (gel or glass) depending on the colloidal volume fraction and ionic strength. We have investigated, through dynamic light scattering, how the aging dynamics of Laponite dispersions at fixed clay concentration (Cw = 2.0%) is modified by the addition of various amounts of poly(ethylene oxide) (PEO) (CPEO = (0.05 ÷ 0.50) %) at two different molecular weights (Mw = 100 kg mol(-1) and Mw = 200 kg mol(-1)). A surprising and intriguing phenomenon has been observed: the existence of a critical polymer concentration C that discriminates between two different aging dynamics. With respect to pure Laponite systems the aging will be assisted (faster) or hindered (slower) for PEO concentrations respectively lower (CPEO < C) or higher (CPEO > C) than the critical concentration. In this way a control on the aging dynamics of PEO-Laponite systems is obtained. A possible explanation based on the balance of competitive mechanisms related to the progressive saturation of the clay surface by polymers is proposed. This study shows how a real control on the aging speed of the PEO-Laponite system is at hand and renders possible a real control of the complex interparticle interaction potential.
Collapse
Affiliation(s)
- Laura Zulian
- Dipartimento di Scienza dei Materiali, Università degli Studi Milano Bicocca, Via Roberto Cozzi, 53 20125 Milano, Italy.
| | | | | | | | | |
Collapse
|
15
|
Chu CY, Chen MH, Wu ML, Chen HL, Chiu YT, Chen SM, Huang CH. Hierarchical structure and crystal orientation in poly(ethylene oxide)/clay nanocomposite films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2886-2895. [PMID: 24555858 DOI: 10.1021/la4042748] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Water-cast nanocomposite films formed by poly(ethylene oxide) (PEO) and Laponite clay were found to display three characteristic levels of structure with large-scale orientation. The first level with the length scale of ca. 30-50 nm was the clay lamellar bundles, which tended to stack perpendicularly to the film surface. The second level with the characteristic length of 1.8 nm was associated with the alternating stacking of the silicate layers and the PEO chains sandwiched between them. The preferred orientations of these two levels of structure were independent of clay content, solvent removal rate for the film preparation, and the crystallization temperature of the PEO chains situating outside the clay bundles. The third level of structure was characterized by the preferred orientation of the PEO crystalline stems with respect to the surface of the silicate layers. Perpendicular orientation always dominated in the nanocomposite films prepared by slow solvent removal irrespective of crystallization temperature. In the films prepared by fast solvent removal, however, parallel crystal orientation set in as the clay concentration exceeded ca. 33 wt %. The preferred crystal orientation was ascribed to the confinement effect imposed by the clay bundles to the crystallization of the PEO chains situating in the interbundle region. In the films cast by slow solvent removal, the weaker confinement associated with the larger interbundle distance led to perpendicular crystal orientation. When the interbundle distance was reduced to ca. 30 nm in the films prepared by rapid solvent evaporation, the strong confinement directed the crystals to form parallel orientation.
Collapse
Affiliation(s)
- Che-Yi Chu
- Department of Chemical Engineering and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University , Hsin-Chu 30013, Taiwan
| | | | | | | | | | | | | |
Collapse
|
16
|
Bodratti AM, Sarkar B, Song D, Tsianou M, Alexandridis P. Competitive Adsorption Between PEO-Containing Block Copolymers and Homopolymers at Silica. J DISPER SCI TECHNOL 2014. [DOI: 10.1080/01932691.2014.880847] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
17
|
Lorthioir C, Khalil M, Wintgens V, Amiel C. Segmental motions of poly(ethylene glycol) chains adsorbed on Laponite platelets in clay-based hydrogels: a NMR investigation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:7859-7871. [PMID: 22512344 DOI: 10.1021/la3010757] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The segmental dynamics of poly(ethylene glycol) (PEG) chains adsorbed on the clay platelets within nanocomposite PEG/Laponite hydrogels was investigated over the tens of microseconds time scale, using combined solution and solid-state NMR approaches. In a first step, the time evolution of the molecular mobility displayed by the PEG chains following the addition to a Laponite aqueous dispersion was monitored during the aggregation of the clay disks and the hydrogel formation, by means of (1)H solution-state NMR. Part of the PEG repeat units were found to get strongly constrained during the gelation process. Comparisons between this time evolution of the PEG local dynamics in the PEG/Laponite/water systems and the increase of the macroscopic storage shear modulus, mainly governed by the assembling of the Laponite disks, indicate that the slowing down of the segmental motions arises from adsorbed PEG repeat units or chain portions strongly constrained between aggregated clay layers. In a second step, after completion of the gelation process, the molecular motions of the adsorbed PEG chains were probed by (1)H solid-state NMR spectroscopy. (1)H double-quantum experiments indicate that the adsorbed PEG repeat units, though reported to be frozen over a few tens of nanoseconds, still display significant reorientational motions over the tens of microseconds time scale. Using a comparison with a model system of amorphized PEG chains, the characteristic frequency of these segmental motions was found to range between 78.0 kHz and 100.7 MHz at 300 K. Interestingly, at this temperature, the level of reorientational motions detected for these adsorbed PEG chain portions was found to be as restricted as the one of bulk amorphous PEG chains, cooled at a slightly lower temperature (about 290 K).
Collapse
Affiliation(s)
- Cédric Lorthioir
- Equipe Systèmes Polymères Complexes, Institut de Chimie et des Matériaux Paris-Est ( UMR 7182 CNRS/Université Paris-Est Créteil ), 2-8 rue Henri Dunant, 94320 Thiais, France.
| | | | | | | |
Collapse
|
18
|
Morariu S, Bercea M. Effect of Temperature and Aging Time on the Rheological Behavior of Aqueous Poly(ethylene glycol)/Laponite RD Dispersions. J Phys Chem B 2011; 116:48-54. [DOI: 10.1021/jp208136g] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Simona Morariu
- Petru Poni Institute of Macromolecular Chemistry, 41-A Grigore Ghica Vodǎ Alley, 700487 Iasi, Romania
| | - Maria Bercea
- Petru Poni Institute of Macromolecular Chemistry, 41-A Grigore Ghica Vodǎ Alley, 700487 Iasi, Romania
| |
Collapse
|
19
|
Wu CJ, Gaharwar AK, Chan BK, Schmidt G. Mechanically Tough Pluronic F127/Laponite Nanocomposite Hydrogels from Covalently and Physically Cross-Linked Networks. Macromolecules 2011. [DOI: 10.1021/ma200562k] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Chia-Jung Wu
- Department of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, Indiana 47907-2032, United States
| | - Akhilesh K. Gaharwar
- Department of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, Indiana 47907-2032, United States
| | - Burke K. Chan
- Department of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, Indiana 47907-2032, United States
| | - Gudrun Schmidt
- Department of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, Indiana 47907-2032, United States
| |
Collapse
|
20
|
Boucenna I, Royon L, Colinart P, Guedeau-Boudeville MA, Mourchid A. Structure and thermorheology of concentrated pluronic copolymer micelles in the presence of laponite particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14430-14436. [PMID: 20726609 DOI: 10.1021/la102744c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Small-angle neutron scattering and thermorheology techniques are used to investigate in detail the effect of laponite particles in aqueous solutions of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), PEO-PPO-PEO, block copolymers in the concentrated regime. At high polymer concentration or temperature, the micellar solutions exhibit a phase transition from fluid to crystal due to crowding of the micelles. The addition of laponite is found to disturb this phase transition. The adsorption of the copolymer unimers onto laponite in large amounts describes these findings. It is shown that the preferred adsorption of the copolymer chains results in a sufficient increase in free volume for the remaining micelles to yield the observed enhancement of the structural disorder.
Collapse
Affiliation(s)
- Imane Boucenna
- Matière et Systèmes Complexes, UMR 7057 CNRS and Université Paris Diderot, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France.
| | | | | | | | | |
Collapse
|
21
|
Sun K, Raghavan SR. Thermogelling aqueous fluids containing low concentrations of Pluronic F127 and laponite nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8015-8020. [PMID: 20408582 DOI: 10.1021/la904907b] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The triblock copolymer Pluronic F127 (PF127) is frequently used in colloidal and pharmaceutical formulations. Concentrated aqueous solutions of PF127 (>15 wt %) are known to undergo thermogelling (i.e., a sol-to-gel transition upon heating), which is attributed to the formation of a volume-filling cubic array of micelles. Here, we report that thermogelling can occur at much lower PF127 concentrations (1.2 to 8 wt %) if nanoparticles of laponite (25-nm-diameter disks) are also present in the formulation. Thermogelling in laponite/PF127 mixtures requires each component to be present above a minimum level. The gels have moduli around 100 Pa, and they can be reversibly liquefied to sols upon cooling. Rheological techniques, small-angle neutron scattering (SANS), and transmission electron microscopy (TEM) are used to characterize the thermogels. We attribute the onset of thermogelling to depletion flocculation of the laponite particles into a network by spherical micelles of PF127.
Collapse
Affiliation(s)
- Kunshan Sun
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742-2111, USA
| | | |
Collapse
|
22
|
Matsunaga T, Endo H, Takeda M, Shibayama M. Microscopic Structure Analysis of Clay−Poly(ethylene oxide) Mixed Solution in a Flow Field by Contrast-Variation Small-Angle Neutron Scattering. Macromolecules 2010. [DOI: 10.1021/ma100476s] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takuro Matsunaga
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Hitoshi Endo
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Makiko Takeda
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Mitsuhiro Shibayama
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| |
Collapse
|
23
|
Hu X, Wang T, Xiong L, Wang C, Liu X, Tong Z. Preferential adsorption of poly(ethylene glycol) on hectorite clay and effects on poly(N-isopropylacrylamide)/hectorite nanocomposite hydrogels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:4233-4238. [PMID: 19994842 DOI: 10.1021/la903298n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Poly(N-isopropylacrylamide)/Laponite nanocomposite hydrogel (NC gel) was synthesized via in situ polymerization in the Laponite suspension containing PEG. The adsorption of PEG on Laponite platelets was characterized by zeta-potential, which decreased with the PEG adsorption. The tensile strength decreased and elongation at break increased with increasing PEG concentration. The effective network chain density of PNIPAm/Laponite NC gels determined from the equilibrium modulus G(e) decreased upon adsorption of PEG on the Laponite. All of these results revealed the preferential adsorption of PEG on the Laponite platelets occupying the active sites for the PNIPAm chain anchoring, which hindered their cross-linking effect in the NC gels. However, the temperature sensitive swelling behavior still remained in the PNIPAm/Laponite NC gels containing PEG with higher swelling volume below the LCST due to the lower cross-linker density. By adjusting the amount of added PEG, we can easily control the properties of the PNIPAm/Laponite NC gels.
Collapse
Affiliation(s)
- Xiaobo Hu
- Research Institute of Materials Science, South China University of Technology, Guangzhou 510640, China
| | | | | | | | | | | |
Collapse
|
24
|
Stefanescu EA, Daranga C, Stefanescu C. Insight into the Broad Field of Polymer Nanocomposites: From Carbon Nanotubes to Clay Nanoplatelets, via Metal Nanoparticles. MATERIALS 2009. [PMCID: PMC5513574 DOI: 10.3390/ma2042095] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Highly ordered polymer nanocomposites are complex materials that display a rich morphological behavior owing to variations in composition, structure, and properties on a nanometer length scale. Metal-polymer nanocomposite materials are becoming more popular for applications requiring low cost, high metal surface areas. Catalytic systems seem to be the most prevalent application for a wide range of metals used in polymer nanocomposites, particularly for metals like Pt, Ni, Co, and Au, with known catalytic activities. On the other hand, among the most frequently utilized techniques to prepare polymer/CNT and/or polymer/clay nanocomposites are approaches like melt mixing, solution casting, electrospinning and solid-state shear pulverization. Additionally, some of the current and potential applications of polymer/CNT and/or polymer/clay nanocomposites include photovoltaic devices, optical switches, electromagnetic interference (EMI) shielding, aerospace and automotive materials, packaging, adhesives and coatings. This extensive review covers a broad range of articles, typically from high impact-factor journals, on most of the polymer-nanocomposites known to date: polymer/carbon nanotubes, polymer/metal nanospheres, and polymer/clay nanoplatelets composites. The various types of nanocomposites are described form the preparation stages to performance and applications. Comparisons of the various types of nanocomposites are conducted and conclusions are formulated.
Collapse
Affiliation(s)
- Eduard A. Stefanescu
- Department of Chemical & Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
- Authors to whom correspondence should be addressed; E-Mail: (E.A.S); Tel.: +1-804-827-7000; Fax: +1-804-828-3846; E-Mail: (C.S.); Tel.: +1-225-578-1720; Fax: +1-225-578- 2697
| | - Codrin Daranga
- Department of Civil & Environmental Engineering, University of Wisconsin, Madison, WI 53706, USA; E-Mail: (C.D.)
| | - Cristina Stefanescu
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
- Authors to whom correspondence should be addressed; E-Mail: (E.A.S); Tel.: +1-804-827-7000; Fax: +1-804-828-3846; E-Mail: (C.S.); Tel.: +1-225-578-1720; Fax: +1-225-578- 2697
| |
Collapse
|
25
|
Wu CJ, Schmidt G. Thermosensitive and Dissolution Properties in Nanocomposite Polymer Hydrogels. Macromol Rapid Commun 2009; 30:1492-7. [DOI: 10.1002/marc.200900163] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 04/21/2009] [Accepted: 04/21/2009] [Indexed: 11/10/2022]
|
26
|
Luan L, Li W, Liu S, Sun D. Phase behavior of mixtures of positively charged colloidal platelets and nonadsorbing polymer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:6349-6356. [PMID: 19466785 DOI: 10.1021/la804023b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We investigated the effect of nonadsorbing polymer on the phase behavior of suspensions of positively charged Mg2Al layered double hydroxide (LDH) platelets by birefringence observations and rheological measurements. We show that the depletion attraction, induced by the addition of a high-molecular-weight polyvinyl pyrrolidone (PVP), enriches the phase behavior of these electrostatically stabilized suspensions. At intermediate LDH and polymer concentration, two isotropic phases (I1-I2) coexist, nematic-nematic (N1-N2) demixing occurs, and a sediment phase is observed, with the appearance of two-, three-, four-, and even six-phase coexistence. Upon increasing the polymer concentration, the I-N phase transition and the sol-gel transition shift to lower LDH concentrations; meanwhile, the I-N coexistent samples enter the purely nematic phase. We explain the richness of the phase behavior in such LDH-PVP mixtures by discussing the interactions among PVP-induced depletion attraction, particle polydispersity, and particle sedimentation.
Collapse
Affiliation(s)
- Lingyu Luan
- Key Laboratory for Colloid and Interface Chemistry of the Education Ministry, Shandong University, Jinan, Shandong 250100, People's Republic of China
| | | | | | | |
Collapse
|
27
|
Lazzara G, Milioto S. Copolymer−Cyclodextrin Inclusion Complexes in Water and in the Solid State. A Physico-Chemical Study. J Phys Chem B 2008; 112:11887-95. [DOI: 10.1021/jp8034924] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- G. Lazzara
- Dipartimento di Chimica Fisica “F. Accascina”, Università degli Studi di Palermo, Viale delle Scienze, Parco D’Orleans II, 90128 Palermo, Italy
| | - S. Milioto
- Dipartimento di Chimica Fisica “F. Accascina”, Università degli Studi di Palermo, Viale delle Scienze, Parco D’Orleans II, 90128 Palermo, Italy
| |
Collapse
|