An effective approach to fabricate high strength polyurethane hydrogels with reversible photochromic performance as a photoswitch

2021 ◽  
Author(s):  
Guangyao Li ◽  
Zhicheng Pan ◽  
Zhanyu Jia ◽  
Juan Wang ◽  
Jianlong Wang ◽  
...  
Keyword(s):  
High Sensitivity ◽  
High Strength ◽  
Optical Devices ◽  
Photochromic Compounds ◽  
Potential Applications ◽  
Organic Photochromic Compounds

Photochromic hydrogels have attracted widespread attention because of their potential applications in optical devices. Spiropyran (SP) is one of the most investigated organic photochromic compounds, which have high sensitivity to...

A self-healable, stretchable, tear-resistant and sticky elastomer enabled by a facile polymer blends strategy

2021 ◽  
Vol 9 (7) ◽  
pp. 3931-3939
Author(s):  
Shiqiang Song ◽  
Honghao Hou ◽  
Jincheng Wang ◽  
Pinhua Rao ◽  
Yong Zhang
Keyword(s):  
Polymer Blends ◽  
High Strength ◽  
Self Healing ◽  
Potential Applications ◽  
Physical Blending

A high-stretchability, high-strength, tear-resistant, self-healing and adhesive elastomer is prepared through a facile and effective physical blending strategy. The elastomer shows potential applications in e-skin devices.

scholarly journals Facile Synthesis and Characterization of Palm CNF-ZnO Nanocomposites with Antibacterial and Reinforcing Properties

2021 ◽  
Vol 22 (11) ◽  
pp. 5781
Author(s):  
Janarthanan Supramaniam ◽  
Darren Yi Sern Low ◽  
See Kiat Wong ◽  
Loh Teng Hern Tan ◽  
Bey Fen Leo ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Cellulose Nanofibers ◽  
High Strength ◽  
Salmonella Typhi ◽  
Particle Sizes ◽  
Mechanical Reinforcement ◽  
Uniform Size ◽  
Preparation Methods ◽  
Potential Applications

Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8–10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.

Thermally irreversible organic photochromic compounds for optical memory

2007 ◽  
Vol 20 (11) ◽  
pp. 1007-1020 ◽  
Author(s):  
V. A. Barachevsky ◽  
Yu. P. Strokach ◽  
Yu. A. Puankov ◽  
M. M. Krayushkin
Keyword(s):  
Optical Memory ◽  
Photochromic Compounds ◽  
Organic Photochromic Compounds

scholarly journals The Role of Bio-Extracted Reduced Graphene Oxide in the Crystallization Kinetics of Chitosan Bio-Polymer

2021 ◽  
pp. 1-4
Author(s):  
Solomon L Joseph ◽  
◽  
Agumba O John ◽  
Fanuel M Keheze ◽  
◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Carbon Nanomaterials ◽  
High Strength ◽  
Limiting Factor ◽  
Reduced Graphene ◽  
Electrical Conductivities ◽  
Coating Method ◽  
Potential Applications ◽  
New Applications

Carbon nanomaterials have recently attracted wide scientific applications due to their tunable properties. These novel materials act as best fillers that can provide substantial benefits due to their high strength, thermal conductivity, and electrical conductivities. With their huge applications as bulk materials, when implemented in polymer matrix as fillers, they give rise to new promising materials with which their properties can be tuned to suit a particular application. Besides the development of these new nanocomposite materials, there exist some challenges which must be fully surpassed to explore the potentiality of application of carbon-based nanocomposites. Reduced graphene oxide is one of the carbon derivatives which has attracted the current advancement in technology, and recently, it found its new applications in super capacitors used in electronic industries. The limiting factor for its exploration is the affordability. New and affordable sources of these graphene-based nanomaterial have to be devised, for fully realization of their potential applications. In this study, reduced graphene oxide and the bio-polymer chitosan were extracted from the locally available bio waste materials. Nanocomposites were prepared at 50% rGO: chitosan ratio. The films were then prepared by spin coating method. Prepared films were subjected to morphological analysis. From the results, it was observed that rGO induced chitosan crystallization, which led to formation of dendritic structures. Cellulose nanocrystals have thus displayed temperature dependent positive uniaxial birefringence

Spun Steel Pipes for the Offshore Industry

1983 ◽  
Vol 105 (1) ◽  
pp. 97-102 ◽  
Author(s):  
A. Royer ◽  
B. Dumas ◽  
M. Gantois
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Centrifugal Casting ◽  
High Strength ◽  
Controlled Rolling ◽  
Climatic Conditions ◽  
Casting Technique ◽  
Steel Pipes ◽  
Potential Applications ◽  
Offshore Industry

Many parts either for sea-line pipes as “buckle” or “crack arrestor,” or for structures may require the use of wall tubular products with high mechanical properties. Such heavy-wall pipes may be produced by centrifugal casting. Two Mn-Mo steels have been developed for medium-wall pipes (e≤35 mm) to be used under very severe climatic conditions: an acicular ferritic steel, a pearlite reduced steel produced by controlled rolling techniques [1, 2, 3]. More alloyed chemical composition and heat-treatments are needed to produce heavy-wall pipes. Then, production of such pipes is more difficult and sometimes impossible. Observations made on controlled-rolled Mn-Mo steel led to a better understanding of the influence of metallurgical structures and chemical composition on steel characteristics. Similar metallurgical structures can only be reached via other routes, for example centrifugal-casting of steel associated with heat-treatment, lead to the production of heavy-wall pipes with high strength and suitable transition temperature. After a brief description of the centrifugal casting technique, we introduce the grades developed for heavy-wall pipes with yield strength up to 100,000 psi. The mechanical properties, Battelle, fatigue, static bending, C.O.D., weldability, etc., of Centrishore II are given and compared to other materials. Possible offshore applications and other potential applications of parts produced by centrifugal casting are described.

scholarly journals High-sensitivity tunneling magneto-resistive micro-gyroscope with immunity to external magnetic interference

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Jin ◽  
Shi-Yang Qin ◽  
Rui Zhang ◽  
Meng-Wei Li
Keyword(s):  
Bridge Circuit ◽  
High Sensitivity ◽  
Micro Electro Mechanical System ◽  
Detection Sensitivity ◽  
Force Detection ◽  
Mems Gyroscope ◽  
Mems Gyroscopes ◽  
Potential Applications ◽  
Magneto Resistance ◽  
Total Sensitivity

Abstract Micro-electro-mechanical system (MEMS) gyroscopes have numerous potential applications including guidance, robotics, tactical-grade navigation, and automotive applications fields. The methods with ability of the weak Coriolis force detection are critical for MEMS gyroscopes. In this paper, we presented a design of MEMS gyroscope based on the tunneling magneto-resistance effect with higher detection sensitivity. Of all these designed parameters, the structural, magnetic field, and magneto-resistance sensitivity values reach to 21.6 nm/°/s, 0.0023 Oe/nm, and 29.5 mV/Oe, thus, with total sensitivity of 1.47 mV/°/s. Multi-bridge circuit method is employed to suppress external magnetic interference and avoid the integration error of the TMR devices effectively. The proposed tunneling magneto-resistive micro-gyroscope shows a possibility to make an inertial grade MEMS gyroscope in the future.

scholarly journals Photoacoustic reporter genes for noninvasive molecular imaging and theranostics

2020 ◽  
Vol 13 (03) ◽  
pp. 2030005
Author(s):  
Zhao Lei ◽  
Yun Zeng ◽  
Xiaofen Zhang ◽  
Xiaoyong Wang ◽  
Gang Liu
Keyword(s):  
Molecular Imaging ◽  
Fluorescent Proteins ◽  
Photoacoustic Imaging ◽  
High Sensitivity ◽  
Reporter Genes ◽  
Biological Processes ◽  
Deep Tissue ◽  
Potential Applications ◽  
Improved Performance

Noninvasive molecular imaging makes the observation and comprehensive understanding of complex biological processes possible. Photoacoustic imaging (PAI) is a fast evolving hybrid imaging technology enabling in vivo imaging with high sensitivity and spatial resolution in deep tissue. Among the various probes developed for PAI, genetically encoded reporters attracted increasing attention of researchers, which provide improved performance by acquiring images of a PAI reporter gene’s expression driven by disease-specific enhancers/promoters. Here, we present a brief overview of recent studies about the existing photoacoustic reporter genes (RGs) for noninvasive molecular imaging, such as the pigment enzyme reporters, fluorescent proteins and chromoproteins, photoswitchable proteins, including their properties and potential applications in theranostics. Furthermore, the challenges that PAI RGs face when applied to the clinical studies are also examined.

scholarly journals Highly Efficient Synthesis of Hindered 3-Azoindoles via Metal-Free C–H Functionalization of Indoles

Synthesis ◽  
2020 ◽  
Vol 52 (04) ◽  
pp. 574-580
Author(s):  
Nicolas Jacob ◽  
Lucas Guillemard ◽  
Joanna Wencel-Delord
Keyword(s):  
Steric Hindrance ◽  
Room Temperature ◽  
Efficient Synthesis ◽  
Atom Economy ◽  
Photochromic Compounds ◽  
Metal Free ◽  
Highly Efficient ◽  
Simple Protocol ◽  
Potential Applications

Although 3-azoindoles have recently emerged as an appealing family of photoswitch molecules, the synthesis of such compounds has been poorly covered in the literature. Herein a high-yielding and operationally simple protocol is reported allowing the synthesis of 3-azoindoles, featuring important steric hindrance around the azo motif. Remarkably, this C–H coupling is characterized by excellent atom economy and occurs under metal-free conditions, at room temperature, and within few minutes, delivering the expected products in excellent yields (quantitatively in most of the cases). Accordingly, a library of new molecules, with potential applications as photochromic compounds, is prepared.

Characterization of Aerogels – Challenges and Prospects

2014 ◽  
Vol 91 ◽  
pp. 54-63 ◽  
Author(s):  
Gudrun Reichenauer
Keyword(s):  
Catalyst Support ◽  
Optical Devices ◽  
Structure Property ◽  
Severe Problem ◽  
The Past ◽  
Structure Property Relationships ◽  
Potential Applications ◽  
Directed Development ◽  
Non Destructive

Aerogels are porous materials with potential applications in fields ranging from thermal insulation, catalyst support, filters, electrical storage, components in optical devices, mechanical damping all the way to drug release. However, careful reliable characterization is the base for both, understanding of fundamental structure - property relationships as well as a directed development of materials and composites for specific applications. The review therefore addressed severe problem upon aerogel characterization that have been identified in the past and presents reliable non-destructive alternatives and novel methods that can be applied for the characterization of aerogels as well as their gel precursors.

Bio-Sensing Textile for Medical Monitoring Applications

2008 ◽  
Vol 57 ◽  
pp. 257-265 ◽  
Author(s):  
Jean Luprano
Keyword(s):  
Health Management ◽  
Health And Safety ◽  
High Sensitivity ◽  
Body Fluids ◽  
Sensor Calibration ◽  
Medical Monitoring ◽  
Healthcare Applications ◽  
Safety Issues ◽  
Important Health ◽  
Potential Applications

The commercial systems using intelligent textiles that start to appear on the market perform physiological measurements such as body temperature, electrocardiogram, respiration rate, etc. and target sport and healthcare applications. Biochemical measurements of body fluids combined with available health monitoring technology will extend these systems by addressing important health and safety issues. BIOTEX, standing for Bio-sensing Textile for Health Management, is a European project, which aims at developing dedicated biochemical sensing techniques that can be integrated into textiles. Such a system would be a major breakthrough for personalized healthcare and would allow for the first time the monitoring of body fluids with sensors distributed in a textile substrate. The potential applications include isolated people, convalescents and patients with chronic diseases, sports performance assessment and training. The project is addressing several challenges, among which: sweat collection and delivery to the sensors, high sensitivity with a wearable system, wearability issues, sensor calibration and lack of research in sweat analysis.

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