Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

scholarly journals Design and Synthesis of Fluoro Analogues of Vitamin D

2021 ◽  
Vol 22 (15) ◽  
pp. 8191
Author(s):  
Fumihiro Kawagoe ◽  
Sayuri Mototani ◽  
Atsushi Kittaka
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Fluorine Atom ◽  
Chemical Properties ◽  
Molecular Structures ◽  
Physical And Chemical Properties ◽  
Design And Synthesis ◽  
Synthetic Methodologies ◽  
Physical And Chemical ◽  
And Chemical Properties

The discovery of a large variety of functions of vitamin D3 and its metabolites has led to the design and synthesis of a vast amount of vitamin D3 analogues in order to increase the potency and reduce toxicity. The introduction of highly electronegative fluorine atom(s) into vitamin D3 skeletons alters their physical and chemical properties. To date, many fluorinated vitamin D3 analogues have been designed and synthesized. This review summarizes the molecular structures of fluoro-containing vitamin D3 analogues and their synthetic methodologies.

Biosynthesis of Silver Nanoparticles: Minireview

2020 ◽  
Vol 6 (2) ◽  
pp. 114-119
Author(s):  
Alaa Alnaimat ◽  
Intesar Aljamaeen
Keyword(s):  
Metal Nanoparticles ◽  
Pathogenic Bacteria ◽  
Wide Spectrum ◽  
High Surface ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Macro Scale ◽  
Physical And Chemical ◽  
Nano Size ◽  
And Chemical Properties

In principle, nanoscience focus on the understanding of the structure, physical and chemical properties of nano size objects. Nanoscience and nanotechnology are both recent and active ongoing branch of science includes multi interdisciplinary sciences. On the other hand, nanotechnology considered as the invested outcomes of the obtained fundamental knowledge about nano objects in various commercial, industrial, environmental and medical sectors. All nano scale matters regardless of their nature referred to as nano-objects were the prefix ‘nano’ mean one millionth of millimeter size. Due to their nano size and high surface area, metal nanoparticles exhibits unique and novel physical and chemical properties compared to their macro scale counterparts. They are considered as very interesting and popular antimicrobial agent with wide spectrum activity against the variety of pathogenic bacteria and fungi. Three main methods were routinely used for metal nanoparticles formation that are chemical, physical and biological approaches. As eco-friendly, cheap and safe synthesis approach without the use of toxic chemicals and free of resulted hazardous byproducts several extracellular and intracellular biological methods using bacteria, fungi, plants or their extracts were reported that known collectively as green nanotechnology

scholarly journals Superphanes: Old Yet New Binding–Agents for Highly Selective Recognition of Fluoride by Size–Sieving Effect

2020 ◽  
Author(s):  
Qing He ◽  
Aimin Li ◽  
Shenglun Xiong ◽  
Wei Zhou ◽  
Huijuan Zhai ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Three Dimensions ◽  
High Symmetry ◽  
X Ray Crystallography ◽  
Design And Synthesis ◽  
Binding Agents ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Sieving Effect ◽  
Guest Chemistry

<p>Superphanes, namely percyclophanes, have been widely investigated for the sake of their aesthetically pleasing structures with high symmetry, intriguing physical and chemical properties and synthetic challenges. Nonetheless, the host–guest chemistry of superphanes remains to be an unmet challenge. Herein, we delineate the design, preparation, characterization, and host–guest chemistry of an unprecedented superphane <b>15</b>, which was evidenced by mass spectroscopy, NMR spectroscopy, X–ray crystallography, and DFT calculations. <b>15</b> features six bridges between two benzene planes, up to 18 C<sub>sp</sub>–<b>H</b> hydrogen–bonding donors well–distributed around the near–closed inner cavity in three dimensions. These allow <b>15</b> to exhibit exclusive selectivity towards F<sup>–</sup> against Cl<sup>–</sup>, Br<sup>–</sup>, I<sup>–</sup>, N<sub>3</sub><sup>–</sup>, SCN<sup>–</sup>, NO<sub>3</sub><sup>–</sup>, ClO<sub>4</sub><sup>–</sup>, SO<sub>4</sub><sup>2–</sup> and HP<sub>2</sub>O<sub>7</sub><sup>3–</sup> due to the size–sieving effect. This contribution opens up new opportunities for design and synthesis of new supramolecular hosts for anions of interest with high selectivity.<br></p>

scholarly journals SiO2@TiO2 Composite Synthesis and Its Hydrophobic Applications: A Review

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 171
Author(s):  
Alicia Rosales ◽  
Karen Esquivel
Keyword(s):  
Composite Material ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Research Information ◽  
Chemical Methods ◽  
Wide Range ◽  
Methods Of Synthesis ◽  
Low Toxicity ◽  
Physical And Chemical ◽  
And Chemical Properties

Titanium dioxide is well known for its photocatalytic properties and low toxicity, meanwhile, silicone dioxide exhibits hydrophobic and hydrophilic properties and thermal stability. The union of these two materials offers a composite material with a wide range of applications that relate directly to the combined properties. The SiO2-TiO2 composite has been synthesized through physical methods and chemical methods and, with adequate conditions, morphology, crystallinity, boundaries between SiO2-TiO2, among other properties, can be controlled. Thus, the applications of this composite are wide for surface applications, being primarily used as powder or coating. However, the available research information on this kind of composite material is still novel, therefore research in this field is still needed in order to clarify all the physical and chemical properties of the material. This review aims to encompass the available methods of synthesis of SiO2-TiO2 composite with modifiers or dopants, the application and known chemical and physical properties in surfaces such as glass, mortar and textile, including aspects for the development of this material.

scholarly journals Synthesis and study of the properties of derivatives 4-phenyl-5-(1H-pyrrol-2-yl)-4H-1,2,4-triazole-3-thiols

2018 ◽  
pp. 59-66
Author(s):  
A. S. Gotsulya ◽  
D. P. Verba ◽  
O. I. Panasenko ◽  
Ye. G. Knysh
Keyword(s):  
Heterocyclic System ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Methods Of Synthesis ◽  
Interesting Object ◽  
Physical And Chemical ◽  
Derivatives Of ◽  
Selection Of ◽  
Base Structure ◽  
And Chemical Properties

The successful use of drugs, derivatives of 1,2,4-triazole, creates the conditionsfor the production and investigation of properties of new derivatives of this heterocyclic system. The aim of this work was synthesis and study of physical and chemical properties of new derivatives of 1,2,4-triazole-3-thiol containing synthon of pyrrole. The object of the study was a 4-phenyl-5-(pyrrol-2-yl)-1,2,4-triazole-3-ylthio-R-carbothioamides. To achieve this goal it was necessary to solve following tasks: to conduct the selection of the optimum base structure to determine the most efficient way of chemical modification of the precursor of targeted synthesis, to carry out selection of necessary methods of synthesis, to investigate the physico-chemical properties and to set the structure of the obtained compounds. The synthesis of target products of the reaction was carried out using as starting material pyrrole, which with using the form non-catalytic form of reaction of the Fridel-Crafts was transformed into 2,2,2-trichloro-1-(pyrrol-2-yl), ethanol. The resulting material in the result of reaction of hydrazinolysis was converted into the pyrrol-2-carbohydrazide. The obtained intermediate product was used in the reaction of nucleophilic joining of phenylisothiocyanate with subsequent intramolecular alkaline heterocyclization. Synthesized thiol was used in the reaction of alkylation. The structure of the obtained substances are confirmed by using elemental analysis, 1H-NMR-spectroscopy, and their individuality – chromatographic methods of analysis. The resulting substances are an interesting object for further studies, especially biological activity.

Superphanes: Old Yet New Binding–Agents for Highly Selective Recognition of Fluoride by Size–Sieving Effect

2020 ◽  
Author(s):  
Qing He ◽  
Aimin Li ◽  
Shenglun Xiong ◽  
Wei Zhou ◽  
Huijuan Zhai ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Three Dimensions ◽  
High Symmetry ◽  
X Ray Crystallography ◽  
Design And Synthesis ◽  
Binding Agents ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Sieving Effect ◽  
Guest Chemistry

<p>Superphanes, namely percyclophanes, have been widely investigated for the sake of their aesthetically pleasing structures with high symmetry, intriguing physical and chemical properties and synthetic challenges. Nonetheless, the host–guest chemistry of superphanes remains to be an unmet challenge. Herein, we delineate the design, preparation, characterization, and host–guest chemistry of an unprecedented superphane <b>15</b>, which was evidenced by mass spectroscopy, NMR spectroscopy, X–ray crystallography, and DFT calculations. <b>15</b> features six bridges between two benzene planes, up to 18 C<sub>sp</sub>–<b>H</b> hydrogen–bonding donors well–distributed around the near–closed inner cavity in three dimensions. These allow <b>15</b> to exhibit exclusive selectivity towards F<sup>–</sup> against Cl<sup>–</sup>, Br<sup>–</sup>, I<sup>–</sup>, N<sub>3</sub><sup>–</sup>, SCN<sup>–</sup>, NO<sub>3</sub><sup>–</sup>, ClO<sub>4</sub><sup>–</sup>, SO<sub>4</sub><sup>2–</sup> and HP<sub>2</sub>O<sub>7</sub><sup>3–</sup> due to the size–sieving effect. This contribution opens up new opportunities for design and synthesis of new supramolecular hosts for anions of interest with high selectivity.<br></p>

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

Sign in / Sign up

Export Citation Format

Share Document