1
|
Weis P, Hess A, Kircher G, Huang S, Auernhammer GK, Koynov K, Butt H, Wu S. Effects of Spacers on Photoinduced Reversible Solid‐to‐Liquid Transitions of Azobenzene‐Containing Polymers. Chemistry 2019; 25:10946-10953. [DOI: 10.1002/chem.201902273] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Indexed: 12/29/2022]
Affiliation(s)
- Philipp Weis
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
| | - Andreas Hess
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
- Present Address: Institute of ChemistryUniversity of Potsdam Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
| | - Gunnar Kircher
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
| | - Shilin Huang
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
- Present Address: School of Materials Science and EngineeringSun Yat-sen University No. 135, Xingang Xi Road Guangzhou 510275 P.R. China
| | - Günter K. Auernhammer
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
- Present Address: Leibniz-Institut für Polymerforschung Hohe Str. 6 01069 Dresden Germany
| | - Kaloian Koynov
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
| | - Hans‐Jürgen Butt
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
| | - Si Wu
- CAS Key Laboratory of Soft Matter ChemistryHefei National Laboratory for Physical Sciences at the MicroscaleDepartment of Polymer Science and EngineeringUniversity of Science and Technology of China Jinzhai Road 96 Hefei 230026 P.R. China
- Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
| |
Collapse
|
2
|
|
3
|
Tao W, Shen J, Chen Y, Liu J, Gao Y, Wu Y, Zhang L, Tsige M. Strain rate and temperature dependence of the mechanical properties of polymers: A universal time-temperature superposition principle. J Chem Phys 2018; 149:044105. [DOI: 10.1063/1.5031114] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Wei Tao
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Jianxiang Shen
- Department of Polymer Science and Engineering, Jiaxing University, Jiaxing 314001, People’s Republic of China
| | - Yulong Chen
- College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, People’s Republic of China
| | - Jun Liu
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029 Beijing, People’s Republic of China
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 100029 Beijing, People’s Republic of China
| | - Yangyang Gao
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Youping Wu
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029 Beijing, People’s Republic of China
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 100029 Beijing, People’s Republic of China
| | - Liqun Zhang
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing, People’s Republic of China
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029 Beijing, People’s Republic of China
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 100029 Beijing, People’s Republic of China
| | - Mesfin Tsige
- Department of Polymer Science, The University of Akron, Akron, Ohio 44325, USA
| |
Collapse
|
4
|
Zheng Y, Wang D, Cui J, Mezger M, Auernhammer GK, Koynov K, Butt HJ, Ikeda T. Redox-Responsive and Thermoresponsive Supramolecular Nanosheet Gels with High Young's Moduli. Macromol Rapid Commun 2018; 39:e1800282. [PMID: 29900622 DOI: 10.1002/marc.201800282] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/16/2018] [Indexed: 01/10/2023]
Abstract
Supramolecular gels made from 2D building blocks are emerging as one of the novel multifunctional soft materials for various applications. This study reports on a class of supramolecular nanosheet gels formed through a reversible self-assembly process involving both intramolecular folding and intermolecular self-assembly of poly[oligo(ethylene glycol)-co-(phenyl-capped bithiophenes)]. Such hierarchical self-assembled structure allows the gels to switch between sol and gel states under either redox or thermostimulus. Moreover, the gels illustrate high Young's moduli, compared to their controls that are made from the same oligo(ethylene glycol) and phenyl-capped bithiophenes blocks but have highly covalent-crosslinked structures. The example might open a window for emerging supramolecular 2D materials to develop mechanically robust and stimuli-responsive soft materials without compromising their intrinsic functions.
Collapse
Affiliation(s)
- Yijun Zheng
- INM - Leibniz Institute for New Materials (INM), Campus D2 2, 66123, Saarbrücken, Germany.,Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, 55128, Mainz, Germany
| | - Dapeng Wang
- Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, 55128, Mainz, Germany.,State Key Laboratory of Polymer Physics and Chemistry, Chinese Academy of Sciences, 7520 Renmin Street, 130022, Changchun, P. R. China
| | - Jiaxi Cui
- INM - Leibniz Institute for New Materials (INM), Campus D2 2, 66123, Saarbrücken, Germany
| | - Markus Mezger
- Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, 55128, Mainz, Germany.,Institute of Physics, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Günter K Auernhammer
- Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, 55128, Mainz, Germany.,Leibnitz Institute for Polymer Research Dresden e. V. (IPF), Hohe Straße 6, 01169, Dresden, Germany
| | - Kaloian Koynov
- Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, 55128, Mainz, Germany
| | - Hans-Jürgen Butt
- Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, 55128, Mainz, Germany
| | - Taichi Ikeda
- Max Planck Institute for Polymer Research (MPIP), Ackermannweg 10, 55128, Mainz, Germany.,Research Center for Functional Materials, National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, 305-0044, Japan
| |
Collapse
|
5
|
Pessot G, Schümann M, Gundermann T, Odenbach S, Löwen H, Menzel AM. Tunable dynamic moduli of magnetic elastomers: from characterization by x-ray micro-computed tomography to mesoscopic modeling. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:125101. [PMID: 29474190 DOI: 10.1088/1361-648x/aaaeaa] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ferrogels and magnetorheological elastomers are composite materials obtained by embedding magnetic particles of mesoscopic size in a crosslinked polymeric matrix. They combine the reversible elastic deformability of polymeric materials with the high responsivity of ferrofluids to external magnetic fields. These materials stand out, for example, for significant magnetostriction as well as a pronounced increase of the elastic moduli in the presence of external magnetic fields. By means of x-ray micro-computed tomography, the position and size of each magnetic particle can be measured with a high degree of accuracy. We here use data extracted from real magnetoelastic samples as input for coarse-grained dipole-spring modeling and calculations to investigate internal restructuring, stiffening, and changes in the normal modes spectrum. More precisely, we assign to each particle a dipole moment proportional to its volume and set a randomized network of springs between them that mimics the behavior of the polymeric elastic matrix. Extending our previously developed methods, we compute the resulting structural changes in the systems as well as the frequency-dependent elastic moduli when magnetic interactions are turned on. Particularly, with increasing magnetization, we observe the formation of chain-like aggregates. Interestingly, the static elastic moduli can first show a slight decrease with growing amplitude of the magnetic interactions, before a pronounced increase appears upon the chain formation. The change of the dynamic moduli with increasing magnetization depends on the frequency and can even feature nonmonotonic behavior. Overall, we demonstrate how theory and experiments can complement each other to learn more about the dynamic behavior of this interesting class of materials.
Collapse
Affiliation(s)
- Giorgio Pessot
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | | | | | | | | | | |
Collapse
|
6
|
Schroyen B, Swan JW, Van Puyvelde P, Vermant J. Quantifying the dispersion quality of partially aggregated colloidal dispersions by high frequency rheology. SOFT MATTER 2017; 13:7897-7906. [PMID: 29022014 DOI: 10.1039/c7sm01690e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An important parameter for the performance of nanomaterials is the degree by which the nanoparticles are dispersed in a matrix. Optical microscopy or scattering methods are useful to characterise the state of dispersion, but are not generally applicable to all materials. Electron microscopy methods are laborious in preparation and typically offer only quantitative information on a very local scale. In the present work we investigate how high frequency rheological measurements can be used for partially dispersed suspensions at intermediate to higher particle loadings, even for high viscous matrices. Although the contribution of the particles is particularly visible in the low frequency linear viscoelastic behaviour, a more direct relationship between rheological properties and degree of dispersion can be derived from the loss modulus in the high frequency limit. To this end, a home-built piezo shear rheometer is constructed to extend the frequency range typically accessible by commercial rotational rheometers. Measurements on spherical silica particles, with a varying degree of dispersion in low molecular weight PDMS, are used to demonstrate how high frequency rheometry can be used to quantify dispersion quality. The linear viscoelastic properties are compared to analytical scaling theories to demonstrate that a hydrodynamically dominated regime is reached. The dependence of the relative high frequency loss modulus on volume fraction is then compared to predictions of a hydrodynamic viscosity model for the derivation of a dispersion quality index. It is used to follow the evolution of the dispersion quality as a function of mixing time and consumed power.
Collapse
Affiliation(s)
- Bram Schroyen
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland.
| | | | | | | |
Collapse
|
7
|
Chen L, Bonaccurso E, Deng P, Zhang H. Droplet impact on soft viscoelastic surfaces. Phys Rev E 2016; 94:063117. [PMID: 28085484 DOI: 10.1103/physreve.94.063117] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Indexed: 06/06/2023]
Abstract
In this work, we experimentally investigate the impact of water droplets onto soft viscoelastic surfaces with a wide range of impact velocities. Several impact phenomena, which depend on the dynamic interaction between the droplets and viscoelastic surfaces, have been identified and analyzed. At low We, complete rebound is observed when the impact velocity is between a lower and an upper threshold, beyond which droplets are deposited on the surface after impact. At intermediate We, entrapment of an air bubble inside the impinging droplets is found on soft surfaces, while a bubble entrapment on the surface is observed on rigid surfaces. At high We, partial rebound is only identified on the most rigid surface at We≳92. Rebounding droplets behave similarly to elastic drops rebounding on superhydrophobic surfaces and the impact process is independent of surface viscoelasticity. Further, surface viscoelasticity does not influence drop spreading after impact-as the surfaces behave like rigid surfaces-but it does affect drop recoiling. Also, the postimpact drop oscillation on soft viscoelastic surfaces is influenced by dynamic wettability of these surfaces. Comparing sessile drop oscillation with a damped harmonic oscillator allows us to conclude that surface viscoelasticity affects the damping coefficient and liquid surface tension sets the spring constant of the system.
Collapse
Affiliation(s)
- Longquan Chen
- State Key Laboratory of Traction Power, Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province, School of Mechanics and Engineering, Southwest Jiaotong University, Chengdu 610031, People's Republic of China
| | | | - Peigang Deng
- School of Science, Wuhan Institute of Technology, Wuhan 430205, People's Republic of China
| | - Haibo Zhang
- College of Materials Science and Engineering, State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
| |
Collapse
|
8
|
Harrold VC, Sharp JS. Optovibrometry: tracking changes in the surface tension and viscosity of multicomponent droplets in real-time. SOFT MATTER 2016; 12:8790-8797. [PMID: 27722476 DOI: 10.1039/c6sm01901c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An instrument was developed for measuring real time changes in the surface tension and viscosity of multicomponent droplets of miscible liquids and other soft materials. Droplets containing glycerol and water were supported on superamphiphobic surfaces and vibrated by applying a short mechanical impulse. Laser light was refracted through the droplets and allowed to fall on the surface of a photodiode. Time dependent variations in the intensity measured by the photodiode during vibration were used to monitor the decay of the droplet oscillations. The frequencies and spectral widths of the droplet vibrational resonances were then obtained from Fourier transforms of these time dependent intensity signals. A recently developed model of viscoelastic droplet vibration was used along with these values and measurements of the drop dimensions to extract the surface tension and viscosity of the drops as they evaporated. Collection of data was automated and values of frequency, spectral width, drop size, surface tension and viscosity were obtained with a time resolution of three seconds over a period of thirty minutes. The values of surface tension and viscosity obtained were shown to be in good agreement with literature values obtained from bulk glycerol/water solutions; thus validating the technique for wider application to other multicomponent liquids and soft matter systems.
Collapse
Affiliation(s)
- Victoria C Harrold
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
| | - James S Sharp
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
| |
Collapse
|
9
|
Pessot G, Löwen H, Menzel AM. Dynamic elastic moduli in magnetic gels: Normal modes and linear response. J Chem Phys 2016; 145:104904. [DOI: 10.1063/1.4962365] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Giorgio Pessot
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | - Hartmut Löwen
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | - Andreas M. Menzel
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| |
Collapse
|
10
|
Harrold VC, Paven M, Vollmer D, Sharp JS. Rheological Properties of Viscoelastic Drops on Superamphiphobic Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4071-4076. [PMID: 27035586 DOI: 10.1021/acs.langmuir.6b00779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The rheological properties of microliter sized drops of polymer solutions were investigated using measurements of their mechanical vibrational response. Drops were suspended on superamphiphobic substrates and vibrated by the application of a short mechanical impulse. Surface vibrations were monitored by refracting laser light through the drops and focusing the refracted light onto the surface of a photodiode. Time dependent variations in the photodiode output were Fourier transformed to obtain the frequency and spectral width of the mechanical resonances of the drops. These quantities were related to the frequency dependent shear storage and loss moduli (G' and G″, respectively) using a simple theoretical model. The resulting rheological properties were found to be in agreement with microrheology measurements of the same solutions. Drop vibration therefore provides a fast and accurate method of quantifying the rheological properties of single drops.
Collapse
Affiliation(s)
- Victoria C Harrold
- School of Physics & Astronomy, University of Nottingham , University Park, Nottingham NG7 2RD, U.K
| | - Maxime Paven
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Doris Vollmer
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - James S Sharp
- School of Physics & Astronomy, University of Nottingham , University Park, Nottingham NG7 2RD, U.K
| |
Collapse
|
11
|
Paez JI, Ustahüseyin O, Serrano C, Ton XA, Shafiq Z, Auernhammer GK, d’Ischia M, del Campo A. Gauging and Tuning Cross-Linking Kinetics of Catechol-PEG Adhesives via Catecholamine Functionalization. Biomacromolecules 2015; 16:3811-8. [DOI: 10.1021/acs.biomac.5b01126] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Julieta I. Paez
- Max- Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
| | - Oya Ustahüseyin
- Max- Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
| | - Cristina Serrano
- Max- Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
| | - Xuan-Anh Ton
- Max- Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
| | - Zahid Shafiq
- Max- Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
| | | | - Marco d’Ischia
- Department
of Chemical Sciences, University of Naples Federico II, Via Cintia, I-80126 Naples, Italy
| | - Aránzazu del Campo
- Max- Planck Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany
- INM − Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
- Saarland University, 66123 Saarbrücken, Germany
| |
Collapse
|
12
|
Diestra-Cruz H, Bukusoglu E, Abbott NL, Acevedo A. Hierarchical microstructures formed by bidisperse colloidal suspensions within colloid-in-liquid crystal gels. ACS APPLIED MATERIALS & INTERFACES 2015; 7:7153-7162. [PMID: 25706308 DOI: 10.1021/am509008m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Past studies have reported that colloids of a single size dispersed in the isotropic phase of a mesogenic solvent can form colloid-rich networks (and gels) upon thermal quenching of the system across the isotropic-nematic phase boundary of the mesogens. Herein we report the observation and characterization of complex hierarchical microstructures that form when bidisperse colloidal suspensions of nanoparticles (NPs; iron oxide with diameters of 188 ± 20 nm or poly(methyl methacrylate) with diameters of 150 ± 15 nm) and microparticles (MPs; polystyrene with diameters of 2.77 ± 0.20 μm) are dispersed in the isotropic phase of 4-pentyl-4'-cyanobiphenyl (5CB) and thermally quenched. Specifically, we document microstructuring that results from three sequential phase separation processes that occur at distinct temperatures during stepwise cooling of the ternary mixture from its miscibility region. The first phase transition demixes the system into coexisting MP-rich and NP-rich phases; the second promotes formation of a particle network within the MP-rich phase; and the third, which coincides with the isotropic-to-nematic phase transition of 5CB, produces a second colloidal network within the NP-rich phase. We quantified the dynamics of each demixing process by using optical microscopy and Fourier transform image analysis to establish that the phase transitions occur through (i) surface-directed spinodal decomposition, (ii) spinodal decomposition, and (iii) nucleation and growth, respectively. Significantly, the observed series of phase transitions leads to a hierarchical organization of cellular microstructures not observed in colloid-in-liquid crystal gels formed from monodisperse colloids. The results of this study suggest new routes to the synthesis of colloidal materials with hierarchical microstructures that combine large surface areas and organized porosity with potential applications in catalysis, separations, chemical sensing, or tissue engineering.
Collapse
Affiliation(s)
- Heberth Diestra-Cruz
- †Department of Chemical Engineering, University of Puerto Rico-Mayagüez, Mayagüez 00681, Puerto Rico
| | - Emre Bukusoglu
- ‡Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Nicholas L Abbott
- ‡Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Aldo Acevedo
- †Department of Chemical Engineering, University of Puerto Rico-Mayagüez, Mayagüez 00681, Puerto Rico
| |
Collapse
|
13
|
Sahoo R, Ananthaiah J, Dabrowski R, Dhara S. Rheology of twist-grain-boundary-A liquid crystals. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:012506. [PMID: 25122323 DOI: 10.1103/physreve.90.012506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Indexed: 06/03/2023]
Abstract
We report studies on the rheological properties of a liquid crystalline analog of Abrikosov phase in type-II superconductors known as twist-grain-boundary-A (TGB(A)) phase. The TGB(A) phase shows a large apparent yield stress compared to the cholesteric (N*) phase. The storage modulus (G') of the TGB(A) phase is significantly larger than the loss modulus (G''). The dynamic relaxation measurements indicate a solid-like behavior of N*, TGB(A), and smectic-C* phases. The complex shear modulus of the TGB(A) phase exhibits a power-law behavior G*(ω) ∼ ω(α) with α ≃ 0.5. The relative amplitude of G' and G'' at various temperatures indicate that the enhanced elasticity of TGB(A) phase is due to the structural defects.
Collapse
Affiliation(s)
- Rasmita Sahoo
- School of Physics, University of Hyderabad, Hyderabad 500046, India
| | - J Ananthaiah
- School of Physics, University of Hyderabad, Hyderabad 500046, India
| | - R Dabrowski
- Institute of Chemistry, Military University of Technology, 00-908, Warsaw, Poland
| | - Surajit Dhara
- School of Physics, University of Hyderabad, Hyderabad 500046, India
| |
Collapse
|
14
|
Wintzenrieth F, Cohen-Addad S, Le Merrer M, Höhler R. Laser-speckle-visibility acoustic spectroscopy in soft turbid media. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:012308. [PMID: 24580228 DOI: 10.1103/physreve.89.012308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Indexed: 06/03/2023]
Abstract
We image the evolution in space and time of an acoustic wave propagating along the surface of turbid soft matter by shining coherent light on the sample. The wave locally modulates the speckle interference pattern of the backscattered light, which is recorded using a camera. We show both experimentally and theoretically how the temporal and spatial correlations in this pattern can be analyzed to obtain the acoustic wavelength and attenuation length. The technique is validated using shear waves propagating in aqueous foam. It may be applied to other kinds of acoustic waves in different forms of turbid soft matter such as biological tissues, pastes, or concentrated emulsions.
Collapse
Affiliation(s)
- Frédéric Wintzenrieth
- Université Paris 6, UMR 7588 CNRS-UPMC, INSP, 4 Place Jussieu, 75252 Paris Cedex 05, France
| | - Sylvie Cohen-Addad
- Université Paris 6, UMR 7588 CNRS-UPMC, INSP, 4 Place Jussieu, 75252 Paris Cedex 05, France and Université Paris-Est, LPMDI, 5 Boulevard Descartes, 77454 Marne-la-Vallée, France
| | - Marie Le Merrer
- Université Paris 6, UMR 7588 CNRS-UPMC, INSP, 4 Place Jussieu, 75252 Paris Cedex 05, France
| | - Reinhard Höhler
- Université Paris 6, UMR 7588 CNRS-UPMC, INSP, 4 Place Jussieu, 75252 Paris Cedex 05, France and Université Paris-Est, LPMDI, 5 Boulevard Descartes, 77454 Marne-la-Vallée, France
| |
Collapse
|
15
|
Wang M, Winter HH, Auernhammer GK. Time and frequency dependent rheology of reactive silica gels. J Colloid Interface Sci 2014; 413:159-66. [DOI: 10.1016/j.jcis.2013.09.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/17/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022]
|
16
|
Whitmer JK, Joshi AA, Roberts TF, de Pablo JJ. Liquid-crystal mediated nanoparticle interactions and gel formation. J Chem Phys 2013; 138:194903. [PMID: 23697437 DOI: 10.1063/1.4802774] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Colloidal particles embedded within nematic liquid crystals exhibit strong anisotropic interactions arising from preferential orientation of nematogens near the particle surface. Such interactions are conducive to forming branched, gel-like aggregates. Anchoring effects also induce interactions between colloids dispersed in the isotropic liquid phase, through the interactions of the pre-nematic wetting layers. Here we utilize computer simulation using coarse-grained mesogens to perform a molecular-level calculation of the potential of mean force between two embedded nanoparticles as a function of anchoring for a set of solvent conditions straddling the isotropic-nematic transition. We observe that strong, nontrivial interactions can be induced between particles dispersed in mesogenic solvent, and explore how such interactions might be utilized to induce a gel state in the isotropic and nematic phases.
Collapse
Affiliation(s)
- Jonathan K Whitmer
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706-1691, USA
| | | | | | | |
Collapse
|
17
|
Zou L, Hwang JY, Kim C. Dynamic arrest of nematic liquid-crystal colloid networks. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:042505. [PMID: 24229199 DOI: 10.1103/physreve.88.042505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Indexed: 06/02/2023]
Abstract
We report interesting self-assembly structures of nematic liquid-crystal colloid (NLCC) networks, which are arrested during cooling from the isotropic temperature to room temperature. The NLCC is composed of sterically stabilized colloidal particles and a nematic liquid crystal (NLC) with nematic-isotropic transition temperature (T_{NI}) that is much higher than those of previously studied 4-Cyano-4'-pentylbiphenyl and N-(4-Methoxybenzylidene)-4-butylaniline. We find that the structure of NLCCs depends on T(NI), cooling rates, and boundary conditions, varying from cellular network to hierarchical fern structures in different length scales. Our time-lapse study shows that the transition from the cellular network to the fern structure directly corresponds to the transition from a spinodal demixing to a nucleation-and-growth mechanism.
Collapse
Affiliation(s)
- Lu Zou
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, USA
| | | | | |
Collapse
|
18
|
Liu D, Wang D, Wang M, Zheng Y, Koynov K, Auernhammer GK, Butt HJ, Ikeda T. Supramolecular Organogel Based on Crown Ether and Secondary Ammoniumion Functionalized Glycidyl Triazole Polymers. Macromolecules 2013. [DOI: 10.1021/ma400407a] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Dian Liu
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz,
Germany
| | - Dapeng Wang
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz,
Germany
| | - Miao Wang
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz,
Germany
| | - Yijun Zheng
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz,
Germany
| | - Kaloian Koynov
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz,
Germany
| | | | - Hans-Jürgen Butt
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz,
Germany
| | - Taichi Ikeda
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz,
Germany
- Polymer Materials
Unit, National Institute for Materials Science, Namiki 1-1, 305-0044 Tsukuba, Japan
| |
Collapse
|
19
|
Yamamoto T, Kawata Y, Yoshida M. Contrasting roles of layered structures in the molecular assembly of liquid crystal matrices on the viscoelastic properties of microparticle/liquid crystal composite gels leading to rigidification and destabilization. J Colloid Interface Sci 2013; 397:131-6. [DOI: 10.1016/j.jcis.2013.01.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 01/18/2013] [Accepted: 01/19/2013] [Indexed: 11/29/2022]
|
20
|
Cui J, Wang M, Zheng Y, Rodríguez Muñiz GM, del Campo A. Light-Triggered Cross-Linking of Alginates with Caged Ca2+. Biomacromolecules 2013; 14:1251-6. [DOI: 10.1021/bm400022h] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jiaxi Cui
- Max-Planck-Institut für Polymerforschung, Ackermannweg
10, 55128 Mainz, Germany
| | - Miao Wang
- Max-Planck-Institut für Polymerforschung, Ackermannweg
10, 55128 Mainz, Germany
| | - Yijun Zheng
- Max-Planck-Institut für Polymerforschung, Ackermannweg
10, 55128 Mainz, Germany
| | | | - Aránzazu del Campo
- Max-Planck-Institut für Polymerforschung, Ackermannweg
10, 55128 Mainz, Germany
| |
Collapse
|
21
|
García-Fernández L, Cui J, Serrano C, Shafiq Z, Gropeanu RA, Miguel VS, Ramos JI, Wang M, Auernhammer GK, Ritz S, Golriz AA, Berger R, Wagner M, del Campo A. Antibacterial strategies from the sea: polymer-bound cl-catechols for prevention of biofilm formation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:529-533. [PMID: 23139083 DOI: 10.1002/adma.201203362] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 09/21/2012] [Indexed: 06/01/2023]
Abstract
Inspired by the amino acid 2-chloro-4,5-dihydroxyphenylalanine (Cl-DOPA), present in the composition of the proteinaceous glue of the sandcastle worm Phragmatopoma californica, a simple strategy is presented to confer antifouling properties to polymer surfaces using (but not releasing) a bioinspired biocide. Cl-Dopamine is used to functionalize polymer materials and hydrogel films easily, to prevent biofilm formation on them.
Collapse
|