scholarly journals The Activation Efficiency of Mechanophores Can Be Modulated by Adjacent Polymer Composition

2020 ◽  
Author(s):  
Sourabh Kumar ◽  
Tim Stauch
Keyword(s):  
Structural Parameters ◽  
Polymer Composition ◽  
Polymer Backbone ◽  
Responsive Materials ◽  
Responsive Polymers ◽  
Quantum Chemical Methods ◽  
Mechanochemical Transformation ◽  
Activation Rate ◽  
Activation Efficiency ◽  
One Step

<div> <div> <div> <p>The activation efficiency of mechanophores in stress-responsive polymers is generally limited by the competing process of unspecific scission in other parts of the polymer chain. Here it is shown that the linker between the mechanophore and the polymer backbone determines the force needed to activate the mechanophore. Using quantum chemical methods, it is demonstrated that the activation forces of three mechanophores (Dewar benzene, benzocyclobutene and gem-dichlorocyclopropane) can be adjusted over a range of almost 300% by modifying the chemical composition of the linker. The results are discussed in terms of changes in electron density, strain distribution and structural parameters during the rupture process. Using these findings it is straightforward to either significantly enhance or reduce the activation rate of mechanophores in stress-responsive materials, depending on the desired use case. The methodology is applied to switch a one-step “gating” of a mechanochemical transformation to a two-step process. </p> </div> </div> </div>

scholarly journals The Activation Efficiency of Mechanophores Can Be Modulated by Adjacent Polymer Composition

2020 ◽  
Author(s):  
Sourabh Kumar ◽  
Tim Stauch
Keyword(s):  
Structural Parameters ◽  
Polymer Composition ◽  
Polymer Backbone ◽  
Responsive Materials ◽  
Responsive Polymers ◽  
Quantum Chemical Methods ◽  
Mechanochemical Transformation ◽  
Activation Rate ◽  
Activation Efficiency ◽  
One Step

<div> <div> <div> <p>The activation efficiency of mechanophores in stress-responsive polymers is generally limited by the competing process of unspecific scission in other parts of the polymer chain. Here it is shown that the linker between the mechanophore and the polymer backbone determines the force needed to activate the mechanophore. Using quantum chemical methods, it is demonstrated that the activation forces of three mechanophores (Dewar benzene, benzocyclobutene and gem-dichlorocyclopropane) can be adjusted over a range of almost 300% by modifying the chemical composition of the linker. The results are discussed in terms of changes in electron density, strain distribution and structural parameters during the rupture process. Using these findings it is straightforward to either significantly enhance or reduce the activation rate of mechanophores in stress-responsive materials, depending on the desired use case. The methodology is applied to switch a one-step “gating” of a mechanochemical transformation to a two-step process. </p> </div> </div> </div>

scholarly journals The activation efficiency of mechanophores can be modulated by adjacent polymer composition

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7391-7396
Author(s):  
Sourabh Kumar ◽  
Tim Stauch
Keyword(s):  
Polymer Composition ◽  
Rupture Force ◽  
Chemical Modifications ◽  
Polymer Backbone ◽  
Activation Efficiency

Chemical modifications of the linking units between a mechanophore and the polymer backbone can significantly enhance or reduce the rupture force of the mechanophore.

The light-controlling of temperature-responsivity in stimuli-responsive polymers

2019 ◽  
Vol 10 (42) ◽  
pp. 5686-5720 ◽  
Author(s):  
Amin Abdollahi ◽  
Hossein Roghani-Mamaqani ◽  
Bahareh Razavi ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Temperature Responsive ◽  
The Media ◽  
Physical And Chemical ◽  
And Chemical Properties

Light-controlling of phase separation in temperature-responsive polymer solutions by using light-responsive materials for reversible controlling physical and chemical properties of the media with an out-of-system stimulus with tunable intensity.

Polarization-dependent deformation in light responsive polymers doped by dichroic dyes

Soft Matter ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1312-1318 ◽  
Author(s):  
Daniele Martella ◽  
Sara Nocentini ◽  
Filippo Micheletti ◽  
Diederik S. Wiersma ◽  
Camilla Parmeggiani
Keyword(s):  
Polarization Dependence ◽  
Responsive Materials ◽  
Responsive Polymers

A polarization-dependence of the deformation in light-responsive materials can be induced through optimizing the dye dopant alignment.

scholarly journals Stimuli-Responsive Materials for Tissue Engineering and Drug Delivery

2020 ◽  
Vol 21 (13) ◽  
pp. 4724 ◽  
Author(s):  
Sofia Municoy ◽  
María I. Álvarez Echazú ◽  
Pablo E. Antezana ◽  
Juan M. Galdopórpora ◽  
Christian Olivetti ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Smart Materials ◽  
Controlled Drug Release ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Stimuli Response ◽  
Materials Used

Smart or stimuli-responsive materials are an emerging class of materials used for tissue engineering and drug delivery. A variety of stimuli (including temperature, pH, redox-state, light, and magnet fields) are being investigated for their potential to change a material’s properties, interactions, structure, and/or dimensions. The specificity of stimuli response, and ability to respond to endogenous cues inherently present in living systems provide possibilities to develop novel tissue engineering and drug delivery strategies (for example materials composed of stimuli responsive polymers that self-assemble or undergo phase transitions or morphology transformations). Herein, smart materials as controlled drug release vehicles for tissue engineering are described, highlighting their potential for the delivery of precise quantities of drugs at specific locations and times promoting the controlled repair or remodeling of tissues.

One-step preparation of magnetically responsive materials from non-magnetic powders

2012 ◽  
Vol 229 ◽  
pp. 285-289 ◽  
Author(s):  
Ivo Safarik ◽  
Katerina Horska ◽  
Kristyna Pospiskova ◽  
Mirka Safarikova
Keyword(s):  
Responsive Materials ◽  
One Step

Thermal Decomposition Modeling and Thermophysical Property Measurement of a Highly Crosslinked Polymer Composite

2009 ◽  
Author(s):  
Aaron L. Brundage ◽  
Kenneth L. Erickson ◽  
Kevin J. Dowding
Keyword(s):  
Thermophysical Properties ◽  
Thermal Response ◽  
Laser Flash ◽  
Polymer Composition ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Inert Filler ◽  
Temperature Range ◽  
One Step ◽  
Practical Geometry

Thermophysical properties including density, specific heat, and thermal diffusivity of a poly (diallyl phthalate) inert filler composite material were characterized over a wide temperature range from room temperature to 800 °C. Over this temperature range, the material decomposition was approximated by a one-step process with first-order kinetics. Thermal kinetics data were obtained by thermal gravimetric analysis with Fourier transform infrared spectroscopy (TGA-FTIR) and thermophysical properties were obtained from differential scanning calorimetry (DSC) and laser flash diffusivity experiments. The response of the material to radiant heating was simulated with a computational heat transfer, multidimensional, finite element code. Additionally, the experimental uncertainty in the measurements was quantified to estimate the uncertainty in the reaction parameters due to heating rate and variability in inert filler-polymer composition in large sample sizes. Hence, the thermal response and the uncertainty were quantified for a complex decomposing material in a practical geometry for technologically important applications.

Stored Energy and Annealing Behavior of Heavily Deformed Aluminium

2012 ◽  
Vol 715-716 ◽  
pp. 367-372 ◽  
Author(s):  
Naoya Kamikawa ◽  
Xiao Xu Huang ◽  
Yuka Kondo ◽  
Tadashi Furuhara ◽  
Niels Hansen
Keyword(s):  
Structural Parameters ◽  
Boundary Energy ◽  
Annealing Treatment ◽  
Stored Energy ◽  
Annealing Behavior ◽  
Roll Bonding ◽  
Boundary Spacing ◽  
Long Time ◽  
One Step ◽  
Relative Change

t has been demonstrated in previous work that a two-step annealing treatment, including a low-temperature, long-time annealing and a subsequent high-temperature annealing, is a promising route to control the microstructure of a heavily deformed metal. In the present study, structural parameters are quantified such as boundary spacing, misorientation angle and dislocation density for 99.99% aluminium deformed by accumulative roll-bonding to a strain of 4.8. Two different annealing processes have been applied; (i) one-step annealing for 0.5 h at 100-400°C and (ii) two-step annealing for 6 h at 175°C followed by 0.5 h annealing at 200-600°C, where the former treatment leads to discontinuous recrystallization and the latter to uniform structural coarsening. This behavior has been analyzed in terms of the relative change during annealing of energy stored as elastic energy in the dislocation structure and as boundary energy in the high-angle boundaries.

Polyanhydrides: Synthesis, Properties, and Applications

2016 ◽  
Vol 69 (11) ◽  
pp. 1223 ◽  
Author(s):  
Katie L. Poetz ◽  
Devon A. Shipp
Keyword(s):  
Thermomechanical Properties ◽  
Polymer Composition ◽  
Surface Erosion ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Monomer Structure ◽  
Synthesis Properties ◽  
Recent Developments ◽  
Delivery Vehicles ◽  
Polymer Erosion

This review focusses on polyanhydrides, a fascinating class of degradable polymers that have been used in and investigated for many bio-related applications because of their degradability and capacity to undergo surface erosion. This latter phenomenon is driven by hydrolysis of the anhydride moieties at the surface and high hydrophobicity of the polymer such that degradation and mass loss (erosion) occur before water can penetrate deep within the bulk of the polymer. As such, when surface-eroding polymers are used as therapeutic delivery vehicles, the rate of delivery is often controlled by the rate of polymer erosion, providing predictable and controlled release rates that are often zero-order. These desirable attributes are heavily influenced by polymer composition and morphology, and therefore also monomer structure and polymerization method. This review examines approaches for polyanhydride synthesis, discusses their general thermomechanical properties, surveys their hydrolysis and degradation processes along with their biocompatibility, and looks at recent developments and uses of polyanhydrides in drug delivery, stimuli-responsive materials, and novel nanotechnologies.

scholarly journals Highly sensitive and multiplexed one-step RT-qPCR for profiling genes involved in the circadian rhythm using microparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mi Yeon Kim ◽  
Seungwon Jung ◽  
Junsun Kim ◽  
Heon Jeong Lee ◽  
Seunghwa Jeong ◽  
...  
Keyword(s):  
Hair Follicles ◽  
Selective Detection ◽  
Multiple Target ◽  
High Demand ◽  
Responsive Materials ◽  
Rna Analysis ◽  
Rna Targets ◽  
Highly Sensitive ◽  
One Step ◽  
Qpcr Platform

AbstractGiven the growing interest in molecular diagnosis, highly extensive and selective detection of genetic targets from a very limited amount of samples is in high demand. We demonstrated the highly sensitive and multiplexed one-step RT-qPCR platform for RNA analysis using microparticles as individual reactors. Those particles are equipped with a controlled release system of thermo-responsive materials, and are able to capture RNA targets inside. The particle-based assay can successfully quantify multiple target RNAs from only 200 pg of total RNA. The assay can also quantify target RNAs from a single cell with the aid of a pre-concentration process. We carried out 8-plex one-step RT-qPCR using tens of microparticles, which allowed extensive mRNA profiling. The circadian cycles were shown by the multiplex one-step RT-qPCR in human cell and human hair follicles. Reliable 24-plex one-step RT-qPCR was developed using a single operation in a PCR chip without any loss of performance (i.e., selectivity and sensitivity), even from a single hair. Many other disease-related transcripts can be monitored using this versatile platform. It can also be used non–invasively for samples obtained in clinics.

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