scholarly journals Crystal engineering construction of caffeic acid derivatives with potential applications in pharmaceuticals and degradable polymeric materials

CrystEngComm ◽  
2020 ◽  
Vol 22 (45) ◽  
pp. 7847-7857
Author(s):  
Zhihan Wang ◽  
Quinton Flores ◽  
Hongye Guo ◽  
Raquel Trevizo ◽  
Xiaochan Zhang ◽  
...  
Keyword(s):  
Caffeic Acid ◽  
Crystal Engineering ◽  
Cycloaddition Reaction ◽  
Polymeric Materials ◽  
Caffeic Acid Derivatives ◽  
Engineering Construction ◽  
Potential Applications

Caffeic acid derivatives with absolute stereostructure were constructed using crystal engineering strategies and topochemical cycloaddition reaction.

Novel organic, polymeric materials for electronics applications

2002 ◽  
Vol 722 ◽  
Author(s):  
Ram W. Sabnis ◽  
Mary J. Spencer ◽  
Douglas J. Guerrero
Keyword(s):  
Optical Density ◽  
Chemical Vapor ◽  
Polymeric Materials ◽  
Substantial Improvement ◽  
Polymeric Systems ◽  
Patterned Wafers ◽  
Visible Spectra ◽  
Potential Applications ◽  
Deep Ultraviolet ◽  
Deposited Films

AbstractNovel organic, polymeric materials and processes of depositing thin films on electronics substrates by chemical vapor deposition (CVD) have been developed and the lithographic behavior of photoresist coated over these CVD films at deep ultraviolet (DUV) wavelength has been evaluated. The specific monomers synthesized for DUV applications include [2.2](1,4)- naphthalenophane, [2.2](9,10)-anthracenophane and their derivatives which showed remarkable film uniformity on flat wafers and conformality over structured topography wafers, upon polymerization by CVD. The chemical, physical and optical properties of the deposited films have been characterized by measuring parameters such as thickness uniformity, solubility, conformality, adhesion to semiconductor substrates, ultraviolet-visible spectra, optical density, optical constants, defectivity, and resist compatibility. Scanning electron microscope (SEM) photos of cross-sectioned patterned wafers showed verticle profiles with no footing, standing waves or undercut. Resist profiles down to 0.10 νm dense lines and 0.09 νm isolated lines were achieved in initial tests. CVD coatings generated 96-100% conformal films, which is a substantial improvement over commercial spin-on polymeric systems. The light absorbing layers have high optical density at 248 nm and are therefore capable materials for DUV lithography applications. CVD is a potentially useful technology to extend lithography for sub-0.15 νm devices. These films have potential applications in microelectronics, optoelectronics and photonics.

scholarly journals Increasing medicinal and phytochemical compounds of coneflower (Echinacea purpurea L.) as affected by NO3−/NH4+ ratio and perlite particle size in hydroponics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Ahmadi ◽  
Abbas Samadi ◽  
Ebrahim Sepehr ◽  
Amir Rahimi ◽  
Sergey Shabala
Keyword(s):  
Particle Size ◽  
Caffeic Acid ◽  
Culture Media ◽  
Chemical Compounds ◽  
Echinacea Purpurea ◽  
Hydroponic Culture ◽  
Peat Moss ◽  
Root Extract ◽  
Caffeic Acid Derivatives ◽  
Phytochemical Compounds

AbstractMedicinal plants are considered as one of the most important sources of chemical compounds, so preparing a suitable culture media for medicinal plant growth is a critical factor. The present study is aimed to improve the caffeic acid derivatives and alkylamides percentages of Echinacea purpurea root extract in hydroponic culture media with different perlite particle size and NO3−/NH4+ ratios. Perlite particle size in the growing media was varied as very coarse perlite (more than 2 mm), coarse perlite (1.5–2 mm), medium perlite (1–1.5 mm), fine perlite (0.5–1 mm), and very fine perlite (less than 0.5 mm) in different ratios to peat moss (including pure perlite, 50:50 v/v, 30:70 v/v, and pure peat moss). Two NO3−/NH4+ ratios (90:10 and 70:30) were tested in each growing media. All phytochemical analyses were performed according to standard methods using high performance liquid chromatography (HPLC). It was found that the E. purpurea grown in the medium containing very fine-grade perlite with 50:50 v/v perlite to peat moss ratio had the maximum caffeic acid derivatives, including chicoric acid (17 mg g−1 DW), caftaric acid (6.3 mg g−1 DW), chlorogenic acid (0.93 mg g−1 DW), cynarin (0.84 mg g−1 DW), and echinacoside (0.73 mg g−1 DW), as well as, alkylamides (54.21%). The percentages of these phytochemical compounds increased by decreasing perlite particle size and increasing of NO3−/NH4+ ratio. The major alkylamide in the E. purpurea root extract was dodeca-2E, 4E, 8Z-10 (E/Z)-tetraenoic acid isobutylamide in all treatments, ranging from 31.12 to 54.21% of total dry weight. It can be concluded that optimizing hydroponic culture media and nutrient solution has significant effects on E. purpurea chemical compounds.

scholarly journals Mechanochemically Gated Photoswitching: Expanding the Scope of Polymer Mechanochromism

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1725-1732 ◽  
Author(s):  
Ross W. Barber ◽  
Molly E. McFadden ◽  
Xiaoran Hu ◽  
Maxwell J. Robb
Keyword(s):  
Mechanical Activation ◽  
Uv Light ◽  
Cycloaddition Reaction ◽  
Polymeric Materials ◽  
Diels Alder ◽  
Information Storage ◽  
Chemical Transformations ◽  
History Of ◽  
Polymer Mechanochemistry ◽  
Stress Sensing

Mechanophores are molecules that undergo productive, covalent chemical transformations in response to mechanical force. Over the last decade, a variety of mechanochromic mechanophores have been developed that enable the direct visualization of stress in polymers and polymeric materials through changes in color and chemiluminescence. The recent introduction of mechanochemically gated photoswitching extends the repertoire of polymer mechanochromism by decoupling the mechanical activation from the visible response, enabling the mechanical history of polymers to be recorded and read on-demand using light. Here, we discuss advances in mechanochromic mechanophores and present our design of a cyclopentadiene–maleimide Diels–Alder adduct that undergoes a force-induced retro-[4+2] cycloaddition reaction to reveal a latent diarylethene photoswitch. Following mechanical activation, UV light converts the colorless diarylethene molecule into the colored isomer via a 6π-electrocyclic ring-closing reaction. Mechanically gated photoswitching expands on the fruitful developments in mechanochromic polymers and provides a promising platform for further innovation in materials applications including stress sensing, patterning, and information storage.1 Introduction to Polymer Mechanochemistry2 Mechanochromic Reactions for Stress Sensing3 Regiochemical Effects on Mechanophore Activation4 Mechanochemically Gated Photoswitching5 Conclusions

Phytochemical profile of Orthosiphon aristatus extracts after storage: Rosmarinic acid and other caffeic acid derivatives

Phytomedicine ◽  
2018 ◽  
Vol 39 ◽  
pp. 49-55 ◽  
Author(s):  
Lee Suan Chua ◽  
Cher Haan Lau ◽  
Chee Yung Chew ◽  
Nurul Izzati Mohd Ismail ◽  
Nitnipa Soontorngun
Keyword(s):  
Caffeic Acid ◽  
Rosmarinic Acid ◽  
Caffeic Acid Derivatives ◽  
Phytochemical Profile

scholarly journals Study of Physical and Degradation Properties of 3D-Printed Biodegradable, Photocurable Copolymers, PGSA-co-PEGDA and PGSA-co-PCLDA

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1263 ◽  
Author(s):  
June-Yo Chen ◽  
Joanne Hwang ◽  
Wai-Sam Ao-Ieong ◽  
Yung-Che Lin ◽  
Yi-Kong Hsieh ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Weight Ratio ◽  
Polymeric Materials ◽  
Pure Substance ◽  
Digital Light Processing ◽  
Glycol Diacrylate ◽  
Young’S Moduli ◽  
Potential Applications ◽  
Degradation Properties

As acrylated polymers become more widely used in additive manufacturing, their potential applications toward biomedicine also raise the demand for biodegradable, photocurable polymeric materials. Polycaprolactone diacrylate (PCLDA) and poly(ethylene glycol) diacrylate (PEGDA) are two popular choices of materials for stereolithography (SLA) and digital light processing additive manufacturing (DLP-AM), and have been applied to many biomedical related research. However, both materials are known to degrade at a relatively low rate in vivo, limiting their applications in biomedical engineering. In this work, biodegradable, photocurable copolymers are introduced by copolymerizing PCLDA and/or PEGDA with poly(glycerol sebacate) acrylate (PGSA) to form a network polymer. Two main factors are discussed: the effect of degree of acrylation in PGSA and the weight ratio between the prepolymers toward the mechanical and degradation properties. It is found that by blending prepolymers with various degree of acrylation and at various weight ratios, the viscosity of the prepolymers remains stable, and are even more 3D printable than pure substances. The formation of various copolymers yielded a database with selectable Young’s moduli between 0.67–10.54 MPa, and the overall degradation rate was significantly higher than pure substance. In addition, it is shown that copolymers fabricated by DLP-AM fabrication presents higher mechanical strength than those fabricated via direct UV exposure. With the tunable mechanical and degradation properties, the photocurable, biodegradable copolymers are expected to enable a wider application of additive manufacturing toward tissue engineering.

Novel Behavior in Smart Polymeric Materials: Stress Memory and its Potential Applications

2016 ◽  
Vol 97 ◽  
pp. 93-99
Author(s):  
Jin Lian Hu ◽  
Harishkumar Narayana
Keyword(s):  
Magnetic Field ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Memory Polymers ◽  
Polymeric Materials ◽  
External Stimulus ◽  
Artificial Muscles ◽  
Recovery Stress ◽  
Stress Memory ◽  
Potential Applications

Materials, structures and systems, responsive to an external stimulus are smart and adaptive to our human demands. Among smart materials, polymers with shape memory effect are at the forefront of research leading to comprehensive publications and wide applications. In this paper, we extend the concept of shape memory polymers to stress memory ones, which have been discovered recently. Like shape memory, stress memory represents a phenomenon where the stress in a polymer can be programmed, stored and retrieved reversibly with an external stimulus such as temperature and magnetic field. Stress memory may be mistaken as the recovery stress which was studied quite broadly. Our further investigation also reveals that stress memory is quite different from recovery stress containing multi-components including elastic and viscoelastic forces in addition to possible memory stress. Stress memory could be used into applications such as sensors, pressure garments, massage devices, electronic skins and artificial muscles. The current revelation of stress memory potentials is emanated from an authentic application of memory fibres, films, and foams in the smart compression devices for the management of chronic and therapeutic disorders.

Sign in / Sign up

Export Citation Format

Share Document