scholarly journals Nature's Nanotechnology

2012 ◽  
Vol 134 (12) ◽  
pp. 28-32
Author(s):  
Bharat Bhushan

This article presents an overview of the emerging field of biomimetics. Biomimetics is highly interdisciplinary and is gaining a foothold in the scientific and technical arena. Biomimetics involves the understanding of biological functions, structures, and principles of various objects found in nature by biologists, physicists, chemists, and material scientists, and the design and fabrication of various materials and devices of commercial interest from bioinspiration. Today, biomimetic materials are moving out of the laboratory and into industrial applications. Significant advancements in nanofabrication allow engineers to replicate structures of interest in biomimetics using smart materials. The commercial applications include nanomaterials, nanodevices, and processes that may enable self-cleaning surfaces or pads that hang pictures without hooks or wires. Some of these applications may at first seem magical, but they simply are the result of applying science and engineering to uncovering the secrets of nature.

2020 ◽  
Vol 09 ◽  
Author(s):  
Ahmed M. Abu-Dief ◽  
W. S. Mohamed

Abstract:: Sustainability environmental lack is a growing and pivotal mater due to the issues: such as disturbances associated with biodiversity pollution, and climate change. Pollutants are the major cause of these environmental threats in the atmosphere. In recently, the nano-based photocatalyst is at the forefront of the author's interest because of its promising potential as a green chemical-based compound, high catalytic activity, the suitable and controllable surface area for wastewater treatment. Semiconductor materials in nanosized scale have electronic and optical properties depend on its building block size, which plays a vital role in developing smart materials that are well efficient for simultaneously destroying harmful chemical contaminants from our environment. This makes these materials used in many possible industrial applications such as water purification. In this Review, we report the most significant results contributing to progress in the area of environmental hazardous pollutant detection and removal focused on water purification especially through photo-catalysis to give readers an overview of the present research trends. Moreover, we analyze previous studies to indicate key principles of photo-catalysis and provide guidelines that can be used to fabricate more efficient photocatalysts.


2018 ◽  
Vol 51 (4) ◽  
pp. 291-336 ◽  
Author(s):  
Antimo Graziano ◽  
Shaffiq Jaffer ◽  
Mohini Sain

Blends of polyethylene (PE) and polypropylene (PP) have always been the subject of intense reasearch for encouraging polymer waste recycling while producing new materials for specific applications in a sustainable way. However, being thermodynamically immiscible, these polyolefins form a binary system usually exhibiting lower performances compared with those of the homopolymers. Many studies have been carried out to better understand the PE/PP blend compatibilization for developing a high-performance and cost-effective product. Both nonreactive and reactive compatibilization promote the brittle to ductile transition for a PE/PP blend. However, the final product usually does not meet the requirements for high demanding commercial applications. Therefore, further PE/PP modification with a reinforcing filler, being either synthetic or natural, proved to be a good method for manufacturing high-performance reinforcend polymer blend composites, with superior and tailored properties. This review summarizes the recent progress in compatibilization techniques applied for enhancing the interfacial adhesion between PE and PP. Moreover, future perspectives on better understanding the influence of themodynamics on PE/PP synergy are discussed to introduce more effective compatibilization strategies, which will allow this blend to be used for innovative industrial applications.


Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 397 ◽  
Author(s):  
Isabel Viera ◽  
Antonio Pérez-Gálvez ◽  
María Roca

The benefit of carotenoids to human health is undeniable and consequently, their use for this purpose is growing rapidly. Additionally, the nutraceutical properties of carotenoids have attracted attention of the food industry, especially in a new market area, the ‘cosmeceuticals.’ Marine organisms (microalgae, seaweeds, animals, etc.) are a rich source of carotenoids, with optimal properties for industrial production and biotechnological manipulation. Consequently, several papers have reviewed the analysis, characterization, extraction and determination methods, biological functions and industrial applications. But, now, the bioaccessibility and bioactivity of marine carotenoids has not been focused of any review, although important achievements have been published. The specific and diverse characteristic of the marine matrix determines the bioavailability of carotenoids, some of them unique in the nature. Considering the importance of the bioavailability not just from the health and nutritional point of view but also to the food and pharmaceutical industry, we consider that the present review responds to an actual demand.


Author(s):  
A Spaggiari ◽  
D Castagnetti ◽  
N Golinelli ◽  
E Dragoni ◽  
G Scirè Mammano

This paper describes the properties and the engineering applications of the smart materials, especially in the mechatronics field. Even though there are several smart materials which all are very interesting from the research perspective, we decide to focus the work on just three of them. The adopted criterion privileges the most promising technologies in terms of commercial applications available on the market, namely: magnetorheological fluids, shape memory alloys and piezoelectric materials. Many semi-active devices such as dampers or brakes or clutches, based on magnetorheological fluids are commercially available; in addition, we can trace several applications of piezo actuators and shape memory-based devices, especially in the field of micro actuations. The work describes the physics behind these three materials and it gives some basic equations to dimension a system based on one of these technologies. The work helps the designer in a first feasibility study for the applications of one of these smart materials inside an industrial context. Moreover, the paper shows a complete survey of the applications of magnetorheological fluids, piezoelectric devices and shape memory alloys that have hit the market, considering industrial, biomedical, civil and automotive field.


Author(s):  
Vandana Prasad ◽  
Lubna Siddiqui ◽  
Pawan Kumar Mishra ◽  
Adam Ekielski ◽  
Sushama Talegaonkar

Background: Synthetic polymers present disadvantages such as high cost, limited availability, safety concerns, environmental hazards and overtime accumulation in body. Lignin, an aromatic biopolymer, is highly abundant and offers various advantages including cost effectiveness, biocompatibility and biodegradability. It also possesses various pharmacological activities including antioxidant, antibacterial, anticancer and UV protection, thus lignin has become a popular biopolymer in recent years and is no more considered as bio-waste rather an extensive research is been carried out on developing it as drug carrier. Lignin also has non-biomedical applications including dispersing agents, surfactants, detergent/cleaning agents, energy storage, etc. Methods: This review compiles patents granted on production of technical lignin, different lignin therapeutic carriers and its biomedical and non-biomedical applications. The literature is collected from recent years including both articles as well as patents and is carefully analyzed and compiled in an easy to comprehend pattern for guiding future research. Results: The reviewed patents and articles highlighted the advancement made in lignin isolation and valorization. Numerous lignin nanoformulations as drug delivery agents or as standalone entities with various pharmacological actions like antibacterial, antioxidant or UV protectant have been reported. As well as industrial applications of lignin as adhesives, insulators or supercapacitors have also made lignin a biopolymer of choice. Conclusion: Lignin being a bio-inspired polymer has huge potential in commercial applications. New methods of lignin isolation from lignocellulosic biomass including physical pretreatments, solvent fraction, and chemical and biological pretreatment have been widely patented. Several micro/nano lignin formulations with improved and controllable reactivity like nanocontainers, nanocapsules, nanoparticles have also been reported recently. Also various pharmacological properties of lignin have also been explored, thus valorization of lignin is a hot topic of hour.


2021 ◽  
Author(s):  
Adel M. El Sayed ◽  
Samy El-Gamal

Abstract Solid polymer electrolytes (SPEs) based on nanocomposites are attracting increasing attention due to their technological and industrial applications. In the present work, a facile aqueous casting method was utilized for the preparation of a starch-chitosan blend loaded with nanosized NaTiO3 (NTO) and co-mixed with ErCl3 (EC) salt. The interactions between OH group of starch and N–H group of chitosan with NTO and EC, and the films' crystallinity and surface morphology were studied by FTIR, XRD, and SEM. UV-Vis-NIR measurements showed the indirect (direct) optical band gaps decreased from 3.4 to 2.0 eV (4.5 to ~ 2.5 eV), i.e., ~ 41–44 % shrinking. At the time that the films maintained a reasonable transmittance. The optical constants of the films; extinction coefficient, refractive index, and the carrier’s concentration to the electron effective mass (N/m*) are reported. N/m* of the pure blend was 4.85 x 1039 (kg-1 m-3) increased to 1.64 times and 2.8 times after loading with 1.0% NTO and 20% EC, respectively. Various dielectric parameters (dielectric constant ε', dielectric loss ε'', ac conductivity σac, and dielectric moduli M' & M'') were evaluated in the frequency range 5 Hz - 1 MHz and temperatures of 298 - 353 K. The conductivity (σac) of the blend increased from 1.10×10-3 S/cm to 8.17×10-3 S/cm after modifying with 20% EC, i.e., became 8 times greater. Moreover, the influence of NTO and EC on the conduction mechanism and Cole-Cole plots are discussed. The improvements in the optical and electrical properties of EC/NTO/blend illustrate the possibility of extending the applications of these smart materials to include optoelectronic devices, batteries, and supercapacitors.


2020 ◽  
Vol 12 (03) ◽  
pp. 2050027 ◽  
Author(s):  
Mohamed Abdelsabour Fahmy

The main aim of this paper is to introduce a new memory-dependent derivative theory to contribute for increasing development of technological and industrial applications of anisotropic smart materials. This theory is called three-temperature anisotropic generalized micropolar piezothermoelasticity. The governing equations of the proposed theory are very difficult to solve analytically because of material anisotropy and its nonlinear properties. Therefore, we propose a new boundary element formulation for solving such equations. The efficiency of our proposed technique has been developed by using an adaptive smoothing and prolongation algebraic multigrid (aSP-AMG) preconditioner to reduce the computation time. The numerical results are presented highlighting the effects of the kernel function and time delay on the temperature and displacements. The numerical results also verify the validity and accuracy of the proposed methodology. It can be concluded from the numerical results of our current complex and general study that some well-known uncoupled, coupled and generalized theories of anisotropic micropolar piezothermoelasticity can be connected with the three-temperature radiative heat conduction to characterize the deformation of anisotropicmicropolar piezothermoelasticstructures in the context of memory-dependent derivative.


Author(s):  
Mukesh Kumar Meena ◽  
Balraj Krishnan Tudu ◽  
Aditya Kumar ◽  
Bharat Bhushan

In this study, a superhydrophobic coating on steel surface has been developed with polyurethane, SiO 2 nanoparticles and hexadecyltrimethoxysilane by using a spin-coating technique. Characterization of the coated steel surface was done by using the contact angle measurement technique, scanning electron microscopy and Fourier transform infrared spectroscopy. With a water tilt angle of 4° ± 2° and static contact angle of 165° ± 5°, the coated surface shows a superhydrophobic and self-cleaning nature. Chemical, thermal, mechanical stability tests and droplet dynamic studies were done to evaluate performance of the coating. Excellent self-cleaning, anti-fogging and anti-corrosion properties of coated steel surfaces make them ideal for industrial applications. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology (part 3)’.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3624 ◽  
Author(s):  
Fabricio Maestá Bezerra ◽  
Manuel José Lis ◽  
Helen Beraldo Firmino ◽  
Joyce Gabriella Dias da Silva ◽  
Rita de Cassia Siqueira Curto Valle ◽  
...  

β-Cyclodextrin (β-CD) is an oligosaccharide composed of seven units of D-(+)-glucopyranose joined by α-1,4 bonds, which is obtained from starch. Its singular trunk conical shape organization, with a well-defined cavity, provides an adequate environment for several types of molecules to be included. Complexation changes the properties of the guest molecules and can increase their stability and bioavailability, protecting against degradation, and reducing their volatility. Thanks to its versatility, biocompatibility, and biodegradability, β-CD is widespread in many research and industrial applications. In this review, we summarize the role of β-CD and its derivatives in the textile industry. First, we present some general physicochemical characteristics, followed by its application in the areas of dyeing, finishing, and wastewater treatment. The review covers the role of β-CD as an auxiliary agent in dyeing, and as a matrix for dye adsorption until chemical modifications are applied as a finishing agent. Finally, new perspectives about its use in textiles, such as in smart materials for microbial control, are presented.


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