861 research outputs found
Stimuli-responsive materials based on interpenetrating polymer liquid crystal hydrogels
Get PDFStimuli-responsive materials based on interpenetrating liquid crystal-hydrogel polymer networks are fabricated. These materials consist of a cholesteric liquid crystalline network that reflects color and an interwoven poly(acrylic acid) network that provides a humidity and pH response. The volume change in the cross-linked hydrogel polymer results in a dimensional alteration in the cholesteric network as well, which, in turn, leads to a color change yielding a dual-responsive photonic material. Furthermore a patterned coating having responsive and static interpenetrating polymer network areas is produced that changes both its surface topography and color. Interpenetrating polymer networks which consist of cholesteric liquid crystals and hydrogels are prepared. These stimuli-responsive materials change color depending on the relative humidity or pH. In addition, patterned dual-responsive polymer films are created changing both topography and color
The role of supramolecular chemistry in stimuli responsive and hierarchically structured functional organic materials
No full textABSTRACT: In this review, we show the important role of supramolecular chemistry in the fabrication of stimuli responsive and hierarchically structured liquid crystalline polymer networks. Supramolecular interactions can be used to create three dimensional order or as molecular triggers in materials that can be applied as actuators, sensors and nanoporous materials
Next generation, in-situ microfluidic flow control using stimuli responsive materials for biomemetic microfluicic platforms
No full textThe requirement of significant off-chip fluid manipulation using high-cost mechanical components has resulted in design limitations in microfluidic devices. We report the use of novel stimuli responsive polymer gel materials for a variety of bio-inspired processes to achieve in-situ microfluidic flow control providing low-cost alternatives to current technologies. These integrated materials result in active microfluidic channels that provide highly simplified, non-contact fluidic control such as valving, mixing and channel sealing. These low-cost materials potentially allow for the creation of complex fluidic arrangements with advanced fluidic control on single use or disposable platforms that are not presently achievable with current technologies
Stimuli responsive delivery vehicles for cardiac microtissue transplantation
No full textCell transplantation has emerged as the most promising therapy for restoring the scarred myocardium in the treatment of heart failure. However, clinical efficacy of (stem) cell therapies is still limited by poor retention rate and survival of injected cells in the ischemic tissue. Here we present a new strategy to deliver microtissues in the treatment of heart dysfunction in order to improve the retention, survival, and integration of the delivered cells. For this purpose, we developed stimuli responsive biodegradable polymer constructs consisting of a thin film of thermosensitive hydrogel coupled to a thin film of non-responsive polymer. Due to the temperature responsive swelling behavior of the hydrogel layer, the bilayer polymer constructs can roll or unroll at will. Therefore they can potentially be used for efficient encapsulation and protection of cell clusters during delivery, while under physiological conditions, the constructs, named cell wraps, can unroll and expose the delivered microtissue to the ischemic tissue
Corrigendum to “Photopolymerization-Enforced Stratification in Liquid Crystal Materials” [Progress in Polymer Science. 114, 2021, 101365]
No full textThe authors regret to inform that…. The author information and affiliation need to be corrected as below. Wei Zhaoa,b,*, Laurens T. de Haana,b, Dirk J. Broera,c, Yang Zhangd, Pengrong Lva, Guofu Zhoua,b,e,* a SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, No 378, West Waihuan Road, Guangzhou Higher Education Mega Center, 510006, Guangzhou China b Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, PR China c Stimuli‐responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, Eindhoven, 5600 MB, the Netherlands d Solar Energy Research Institute, Yunnan Normal University, Kunming 650500, China e Shenzhen Guohua Optoelectronics Tech. Co. Ltd., Shenzhen 518110, China Author would like to apologize for the inconvenience caused
Stimuli-responsive photonic polymer coatings
Get PDFThis feature article focuses on the highlights in the development of photonic polymer coatings that can change their volume or surface topology in a reversible, dynamic fashion when exposed to an external stimulus. Topographic response is established using hydrogels or liquid crystal polymer networks. By changing the surface corrugation in response to light various functional coating properties can be modulated, for instance wettability and/or mechanical friction. The same volume changes in photonic coatings caused by different stimuli lead to changes in light reflection
Hydrogen-Bonded Supramolecular Liquid Crystal Polymers: Smart Materials with Stimuli-Responsive, Self-Healing, and Recyclable Properties
Get PDFHydrogen-bonded liquid crystalline polymers have emerged as promising “smart” supramolecular functional materials with stimuli-responsive, self-healing, and recyclable properties. The hydrogen bonds can either be used as chemically responsive (i.e., pH-responsive) or as dynamic structural (i.e., temperature-responsive) moieties. Responsiveness can be manifested as changes in shape, color, or porosity and as selective binding. The liquid crystalline self-organization gives the materials their unique responsive nanostructures. Typically, the materials used for actuators or optical materials are constructed using linear calamitic (rod-shaped) hydrogen-bonded complexes, while nanoporous materials are constructed from either calamitic or discotic (disk-shaped) complexes. The dynamic structural character of the hydrogen bond moieties can be used to construct self-healing and recyclable supramolecular materials. In this review, recent findings are summarized, and potential future applications are discussed
Environmentally responsive photonic polymers
Get PDFStimulus-responsive photonic polymer materials that change their reflection colour as function of environmental stimuli such as temperature, humidity and light, are attractive for various applications (e.g. sensors, smart windows and communication). Polymers provide low density, tunable and patternable materials. This feature article focusses on various autonomously responding photonic polymer materials such as hydrogels, block copolymers and liquid crystals and discusses their potential industrial implementation
Stimuli-responsive materials: A smart way to study dynamic cell responses
Get PDFCells in the body reside within the extracellular matrix (ECM), a three-dimensional environment that not only provides structural support for the cells, but also influences cellular processes, like migration and differentiation. The ECM and the cells continuously engage in a complex and highly dynamic interplay, shaping both the matrix as well as the cellular outcome. To study these dynamic, bidirectional interactions in a systematic manner, the ability to dynamically control cellular environments is highly desirable. Stimuli-responsive materials are a class of materials that have been engineered to respond to external cues, e.g., light, electricity, or magnetic field, and therefore hold fascinating potentials as an ideal experimental platform to introduce changing spatiotemporal signals to cells. Here, we review the state of the art in stimuli-responsive materials and their design strategies, with an emphasis on the dynamic introduction of physical and mechanical cues. The effects of such dynamic stimuli on the responses of living cells are examined on three different levels: cellular phenotypes, intracellular and cytoskeletal changes, and nuclear and epigenetic effects. Finally, we discuss the current challenges and limitations as well as the potential outlooks in exploiting stimuli-responsive biomaterials
Intelligent stimuli-responsive materials : from well-defined nanostructures to applications
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