• Title/Summary/Keyword: nano-capsules

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Experimental investigation of self-healing concrete after crack using nano-capsules including polymeric shell and nanoparticles core

  • Taheri, Mojtaba Naseri;Sabet, Seyyed Ali;Kolahchi, Reza
    • Smart Structures and Systems
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    • v.25 no.3
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    • pp.337-343
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    • 2020
  • In this paper, we focused on the self-healing concrete using new nano-capsules. Three types of nano-capsules with respect to availability, high strength and temperature tolerance are used; type 1 is URF and polyethylene (PE) as shell and nano titanium oxide (TiO2) as core, type 2 is URF and PE as shell and nano silica oxide (SiO2) as core, type 3 is PE as shell and nano silica oxide (SiO2) as core. The concrete samples mixed by nano-capsules with three percents of 0.5, 1 and 1.5. Based on experimental tests and the compressive strength of samples, the URF-PE-SiO2 is selected for additional tests of compressive strength before and after recovery, ultrasonic test, ion chlorine and water penetration depths. After careful investigation, it is concluded that the optimum value of URF-PE-SiO2 nano-capsules is 0.5% since leads to higher compressive strength, ultrasonic test, ion chlorine and water penetration depths.

Various Types and Manufacturing Techniques of Nano and Micro Capsules for Nanofood

  • Kim, Dong-Myong
    • Journal of Dairy Science and Biotechnology
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    • v.24 no.1
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    • pp.53-63
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    • 2006
  • Nano and micro capsulation (NM capsulation) involve the incorporation for nanofood materials, enzymes, cells or other materials in small capsules. Since Kim D. M. (2001) showed that a new type of food called firstly the name of nanofood, which means nanotechnology for food, and the encapsulated materials can be protected from moisture, heat or other extreme conditions, thus enhancing their stability and maintaining viability applications for this nanofood technique have increased in the food. NM capsules for nanofood is also utilized to mask odours or tastes. Various techniques are employed to form the capsules, including spray drying, spray chilling or spray cooling, extrusion coating, fluidized bed coating, liposome entrapment, coacervation, inclusion complexation, centrifugal extrusion and rotational suspension separation. Each of these techniques is discussed in this review. A wide variety of nanofood is NM capsulated - flavouring agents, acids, bases, artificial sweeteners, colourants, preservatives, leavening agents, antioxidants, agents with undesirable flavours, odours and nutrients, among others. The use of NM capsulation for sweeteners such as aspartame and flavors in chewing gum is well known. Fats, starches, dextrins, alginates, protein and lipid materials can be employed as encapsulating materials. Various methods exist to release the ingredients from the capsules. Release can be site-specific, stage-specific or signaled by changes in pH, temperature, irradiation or osmotic shock. NM capsulation for the nanofood, the most common method is by solvent-activated release. The addition of water to dry beverages or cake mixes is an example. Liposomes have been applied in cheese-making, and its use in the preparation of nanofood emulsions such as spreads, margarine and mayonnaise is a developing area. Most recent developments include the NM capsulation for nanofood in the areas of controlled release, carrier materials, preparation methods and sweetener immobilization. New markets are being developed and current research is underway to reduce the high production costs and lack of food-grade materials.

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Iron Oxide Nanoparticle-incorporated Alginate Capsules as Magnetic Field-assisted Potential Delivery Platforms for Agriculture Pesticides and Biocontrol Agents

  • Lee, Dohyeon;Choi, Kyoung Soon;Kim, Daun;Park, Sunho;Kim, Woochan;Jang, Kyoung-Je;Lim, Ki-Taek;Chung, Jong Hoon;Seonwoo, Hoon;Kim, Jangho
    • Journal of Biosystems Engineering
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    • v.42 no.4
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    • pp.323-329
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    • 2017
  • Purpose: Biocompatible capsules have recently been highlighted as a novel platform for delivering various components, such as drug, food, and agriculture pesticides, to overcome the current limitations of living systems, such as those in agriculture, biology, the environment, and foods. However, few active targeting systems using biocompatible capsules and physical forces simultaneously have been developed in the agricultural engineering field. Methods: Here, we developed an active targeting delivery platform that uses biocompatible alginate capsules and controls movements by magnetic forces for agricultural and biological engineering applications. We designed and fabricated large-scale biocompatible capsules, using custom-made nozzles ejecting alginate solutions for encapsulation. Results: To develop the active target delivery platforms, we incorporated iron oxide nanoparticles in the large-scale alginate capsules. The sizes of alginate capsules were controlled by regulating the working conditions, such as concentrations of alginate solutions and iron oxide nanoparticles. Conclusions: We confirmed that the iron oxide particle-incorporated large-scale alginate capsules moved actively in response to magnetic fields, which will be a good strategy for active targeted delivery platforms for agriculture and biological engineering applications, such as for the controlled delivery of agriculture pesticides and biocontrol agents.

Development of Functional Milk and Dairy Products by Nanotechnology (나노 기술을 이용한 기능성 우유 및 유제품의 개발 연구)

  • Gwak, Hae-Su
    • Journal of Dairy Science and Biotechnology
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    • v.23 no.1
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    • pp.27-37
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    • 2005
  • The development of functional foods started booming from several years ago in the world. The size of functional materials are in the range of micrometer level. This size can be much smaller into nanometer level to be more effective. We face some problems from the materials, such as flavor, taste, color, viscosity, etc. in functional materials. The problems can be solved by micro / nanoencapsulation technique. This paper showed some results of the research related on the technique for functional milks and dairy products. The nono / microcapsules are the form of liquid instead of solid. Coating materials used were fatty acid esters, and core materials were lactase, iron, ascorbic acid. isoflavone, and chitooligosaccharide. The ranges of capsules are from 100 nm to 200 ${\mu}$m. The sample milks added nano/microcapsules were homogeneous and prevented the defects of core materials. It was observed that nano / microcapsules in milk and dairy products were effective as functional material without defaults. It was indicated that targeted functional foods can be developed further in various foods by nanotechnology.

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Sports impact on the nanomedicine absorption in drug delivery

  • Mengqian Hou;Xin Fang;Teng Nan
    • Advances in nano research
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    • v.14 no.2
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    • pp.179-193
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    • 2023
  • Physical activities enhance blood flow in the vessels, which may increase the quality of medicine delivery. The emergence of revolutionary technologies such as nanoscience, made it possible to treat the incurable illnesses such as cancer. This paper investigates the impact of sport and physical exercises on the quality and quantity of the drug-delivery based on the mathematical modeling of a nanomotor made by nanotubes carrying the nano-drug capsules. Accordingly, the mathematical equations of rotating nanomotor are generated by considering the both of higher-order beam model and nonlocal strain gradient model, as a comprehensive continuum theory. Next, through the generalized differential quadrature together with Newmark-beta methods, the differential relations are discretized and solved. Finally, the impact of varied parameters on the dynamical behavior of the nanomotor is examined in detail. The outcomes of this investigation can be useful to achieve an excellent design of nanomotors carrying nano-drugs.

Preparation and Properties of Poly($\varepsilon$-caprolactone) Nanocapsules Containing Tricrecyl phosphate by Emulsion-diffusion Method (유화확산법을 이용한 트리크리실 포스페이트 폴리입실론카프로락톤 나노캡슐의 제조와 성질)

  • Jeong, Cheon-Hui;Park, Yun-Jeong;Kim, Hye-In;Park, Su-Min
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2008.10a
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    • pp.69-70
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    • 2008
  • The study has attempted to prepare nanocapsules containing Tricrecyl phosphate by Emulsion-diffusion method. The study has focused on finding a optimum condition for preparering nano capsules and effect on size distribution and surface morphology.

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Synthesis of Core-Shell Silica Nanoparticles with Hierarchically Bimodal Pore Structures

  • Yun, Seok-Bon;Park, Dae-Geun;Yun, Wan-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.467-467
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    • 2011
  • Reflecting the growing importance of nanomaterials in science and technology, controlling the porosity combined with well-defined structural properties has been an ever-demanding pursuit in the related fields of frontier researches. A number of reports have focused on the synthesis of various nanoporous materials so far and, recently, the nanomaterials with multimodal porosity are getting an emerging importance due to their improved material properties compared with the mono porous materials. However, most of those materials are obtained in bulk phases while the spherical nanoparticles are one of the most practical platforms in a great number of applications. Here, we report on the synthesis of the core-shell silica nanoparticles with double mesoporous shells (DMSs). The DMS nsnoparticles are spherical and monodispersive and have two different mesoporous shells, i.e., the bimodal porosity. It is the first example of the core-shell silica nanoparticles with the different mesopores coexisting in the individual nanoparticles. Furthermore, the carbon and silica hollow capsules were also fabricated via a serial replication process.

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Nano-capsulation of L-Ascorbic Acid in Nonaqueous System (L-Ascorbic Acid의 비수계 나노 캡슐화)

  • Hong, Joo-Hee;Song, Ki-Se;Kim, Kyoung-Jun;Lee, Chae-Seong;An, Byeong-Min;Kim, Byoung-Sik
    • Applied Chemistry for Engineering
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    • v.19 no.6
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    • pp.604-608
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    • 2008
  • In this work, the basic research for nano-capsulation of L-ascorbic acid (Vitamin C) in nonaqueous system was carried out. 500 nm-sized nano-capsules were prepared in nonaqueous system, and the emulsified capsule had mean size of 410 nm. The stability test on the temperature and the storage periods was performed at 4, 20, and $30^{\circ}C$ for 30 days. After 5 days, L-ascorbic acid was extricated 5.1, 9.3, and 12.5% at each temperature, but only 1~2 % was extricated after the time span. Likewise, the results of the skin susceptibility on women and men, each 10 persons, revealed that the very thin allergy was shown from only a woman after 2 days, but it was not shown from the others.

Thermal Properties and Microencapsulation of a Phosphate Flame Retardant with a Epoxy Resin (에폭시 수지를 이용한 인계 난연제의 마이크로캡슐화 및 열적 특성 연구)

  • Baek Kyung-Hyun;Lee Jun-Young;Hong Sang-Hyun;Kim Jung-Hyun
    • Polymer(Korea)
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    • v.28 no.5
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    • pp.404-411
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    • 2004
  • The microcapsules containing triphenyl phosphate (TPP), a flame retardant, were prepared by phase-inversion emulsification technique using the epoxy resin (Novolac type) with excellent physical properties and network structure. This microencapsulation process was adopted for the protection of TPP evaporation and wetting of polymer composite during the polymer blend processing. The TPP, epoxy resin and mixed surfactants were emulsified to oil in water (O/W) by the phase inversion technology and then conducted on the crosslinking of epoxy resin by in-situ polymerization. The capsule size and size distribution of TPP capsules was controlled by mixed surfactant ratio, concentration and TPP contents, The formation and thermal property of TPP capsules were measured by differential scanning calorimetry and thermogravimetric analysis. The morphology and size of TPP capsules were also investigated by scanning and transmission electron microscopies. As the surfactant concentration increased, the TPP capsules were more spherical and mono-dispersed at the same weight ratio of mixed surfactants (F127: SDBS).

Ammonium Production During the Nitrogen-Fixing Process by Wild Paenibacillus Strains and Cell-Free Extract Adsorbed on Nano $TiO_2$ Particles

  • Shokri, Dariush;Emtiazi, Giti
    • Journal of Microbiology and Biotechnology
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    • v.20 no.8
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    • pp.1251-1258
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    • 2010
  • During the nitrogen-fixing process, ammonia ($NH_3$) is incorporated into glutamate to yield glutamine and is generally not secreted. However, in this study, $NH_3$-excreting strains of nitrogen-fixing Paenibacillus were isolated from soil. The ammonium production by the Paenibacillus strains was assayed in different experiments (dry biomass, wet biomass, cell-free extract, and cell-free extract adsorbed on nano $TiO_2$ particles) inside an innovative bioreactor containing capsules of $N_2$ and $H_2$. In addition, the effects of different $N_2$ and $H_2$ treatments on the formation of $NH_3$ were assayed. The results showed that the dry biomass of the strains produced the most $NH_3$. The dry biomass of the Paenibacillus strain E produced the most $NH_3$ at 1.50, 0.34, and 0.27 ${\mu}M$ $NH_3$/mg biomass/h in the presence of $N_2$ + $H_2$, $N_2$, and $H_2$, respectively, indicating that a combined effluent of $N_2$ and $H_2$ was vital for $NH_3$ production. Notwithstanding, a cell-free extract (CFE) adsorbed on nano $TiO_2$ particles produced the most $NH_3$ and preserved the enzyme activities for a longer period of time, where the $NH_3$ production was 2.45 ${\mu}M$/mg CFE/h over 17 h. Therefore, the present study provides a new, simple, and inexpensive method of $NH_3$ production.