• Title/Summary/Keyword: responsive materials

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Molecularly engineered switchable photo-responsive membrane in gas separation for environmental protection

  • Rosli, Aishah;Low, Siew Chun
    • Environmental Engineering Research
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    • v.25 no.4
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    • pp.447-461
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    • 2020
  • In recent years, stimuli-responsive materials have garnered interest due to their ability to change properties when exposed to external stimuli, making it useful for various applications including gas separation. Light is a very attractive trigger for responsive materials due to its speedy and non-invasive nature as well as the potential to reduce energy costs significantly. Even though light is deemed as an appealing stimulus for the development of stimuli-responsive materials, this avenue has yet to be extensively researched, as evidenced by the fewer works done on the photo-responsive membranes. Of these, there are even less research done on photo-responsive materials for the purpose of gas separation, thus, we have collected the examples that answer both these criteria in this review. This review covers the utilisation of photo-responsive materials specifically for gas separation purposes. Photo-chromic units, their integration into gas separation systems, mechanism and research that have been done on the topic so far are discussed.

A Study on the Reduction of VOCs Generated from Vehicle Interior Parts and Materials Using Visible-light Responsive Photocatalyst (가시광촉매를 이용한 자동차 내장재로부터 발생하는 VOCs의 저감연구)

  • Choi, Sei-Young;Yang, Seung-Gi
    • Elastomers and Composites
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    • v.48 no.3
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    • pp.209-215
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    • 2013
  • On this study, visible-light responsive photocatalyst prepared by sol-gel method was evaluated the effect of the reduction of volatile organic compounds (VOCs) occurred in vehicle interior and its property was examined. According to UV/visible result, visible-light responsive photocatalyst was found that the UV-visible peak is red shift at 420nm, is sensitive in the visible light region. With vehicle interior parts and materials coated visible-light responsive photocatalyst, VOCs was measured by GC/MS. Measuring the VOCs generated from vehicle interior parts and materials, the reduction of VOCs was confirmed.

VOCs Reduction of Visible-light Responsive Photocatalyst coated nylon/polyester composite fiber for Vehicle Interior Parts and Materials (가시광 감응형 광촉매가 코팅처리된 자동차내장재용 Nylon/Polyester 복합섬유의 VOCs 저감)

  • Choi, Sei-Young
    • Elastomers and Composites
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    • v.49 no.1
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    • pp.53-58
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    • 2014
  • In this study, characteristics of visible-light responsive photocatalyst Weltouch, especially VOCs reduction of visible-light responsive photocatalyst coated nylon/polyester composite fiber for vehicle interior parts and materials were evaluated. Visible-light responsive photocatalyst Weltouch was observed for both anatase phase and rutile phase. It is activated by light longer than 420nm. VOCs and formaldehyde generated from visible-light responsive photocatalyst treated nylon/polyester composite fiber were reduced confirmly. Visible-light responsive photocatalyst was firmly attached to the surface of nylon/polyester composite fiber without elimination even after 25 times repeated washing. And washing durability of nylon/polyester composite fiber confirmed the excellence that reduction effects of VOCs after repeated washing has appeared as much as before washing.

A Study on the Volatile Organic Compounds Analysis Method for Visible Light-Responsive Photocatalyst Treated Vehicle Interior Materials (가시광촉매가 처리된 자동차 내장재의 VOC 분석방법에 대한 연구)

  • Choi, Sei Young
    • Elastomers and Composites
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    • v.48 no.3
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    • pp.221-224
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    • 2013
  • In this study, VOC analysis method of vehicle interior materials and parts treated to visible-light responsive photocatalyst was tested by sample bag filled with air instead of nitrogen. As a result, when analyzed VOC of vehicle interior materials and parts, sample bag filled with the nitrogen was not confirmed of effect reducing VOCs and formaldehyde. However, VOCs and formaldehyde of sample bag that was filled with air instead of nitrogen, decreased significantly. Reaction effect for visible light-responsive photocatalyst was confirmed that sample bag of vehicle interior materials and parts should be filled with air instead of nitrogen.

Tunable Photonic Band Gap Materials and Their Applications

  • Gang, Yeong-Jong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.261-261
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    • 2010
  • Photonic band gap (PBG) materials have been of great interest due to their potential applications in science and technology. Their applications can be further extended when PBG becomes tunable against various chemical and electrical stimuli. In recent, it was found that tunable photonic band gap materials can be achieved by incorporating stimuli-responsive smart gels into PBG materials. For example, the characteristic volume phase transition of gels in response to the various external stimuli including temperature, pH, ionic strength, solvent compositions and electric field were recently combined with the unique optical properties of photonic crystals to form unprecedented highly responsive optical components. Since these responsive photonic crystals are capable of reversibly converting chemical or electrical energy into characteristic optical signals, they have been considered as a good platform for label-free chemical or biological detection, actuators or optical switches as well as a model system for investigating gel swelling behavior. Herein, we report block copolymer photonic gels self-assembled from polystyrene-b-poly (2-vinyl pyridine) (PS-b-P2VP) block copolymers. In this talk, we are going to demonstrate that selective swelling of lamellar structure can be effectively utilized for fabricating PBG materials with extremely large tunability. Optical properties and their applications will be discussed.

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Behaviour of field-responsive suspensions under oscillatory shear flow

  • Keentok, Matti;See, Howard
    • Korea-Australia Rheology Journal
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    • v.19 no.3
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    • pp.117-123
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    • 2007
  • There has been considerable interest in recent years in field-responsive suspensions, which are of some importance in industry in many different applications. The microstructure of these materials is a significant issue which can be probed by rheological measurements. In this study, measurements were made of a magnetorheological fluid (MRF) under steady and oscillatory shear flow, with and without a magnetic field. Mathematical inversion was used to derive the relaxation time spectrum of the MRF from oscillatory shear data. Experimental evidence is presented of the gel-like properties of this MRF.

Loading Behavior of pH-Responsive P(MAA-co-EGMA) Hydrogel Microparticles for Intelligent Drug Delivery Applications (지능형 약물전달시스템을 위한 pH 감응형 P(MAA-co-EGMA) 수화젤 미세입자의 탑재거동)

  • Shin, Young-Chan;Kim, Kyu-Sik;Kim, Bum-Sang
    • Polymer(Korea)
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    • v.32 no.5
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    • pp.421-426
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    • 2008
  • pH-responsive P(MAA-co-EGMA) hydrogel microparticles were synthesized via dispersion photo polymerization and the feasibility of the particles as the cosmetic formulation was investigated. Rh-B and the functional materials for the cosmetic application such as ascorbic acid, adenosine, EGCG, and arbutin were loaded in the P (MAA-co-EGMA) hydrogel microparticles in order to examine the interaction between the hydrogel and the loaded materials. In the loading experiments, Rh-B showed the highest loading efficiency to the P(MAA-co-EGMA) hydrogels due to the electrostatic attraction between the negative charge of the hydrogels and the positive charge of Rh-B at the ionized states. However, the functional materials showed relatively low loading efficiencies because of the electrostatic repulsions between the negative charges of both the hydrogels and the materials at the ionized states. In addition, P(MAA-co-EGMA) hydrogel microparticles showed pH-responsive release behavior of Rh-B according to the external pH changes.

Diffraction Behaviors of New Photopolymers Containing the Dendritic Molecule

  • Kim Go Woon;Jun Woong Gi;Lee Sang Kyu;Cho Min Ju;Jin Jung-Il;Choi Dong Hoon
    • Macromolecular Research
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    • v.13 no.6
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    • pp.477-482
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    • 2005
  • Photopolymers are attractive materials for holographic 3-D data storage because of their high photosensitivity and large refractive index modulation. We synthesized the six-armed dendrimer for fabricating the new photopolymer. It was prepared using the initiating mixture of hexaarylbiimidazole (HABI), mercapto-benzoxazole (MOBZ), and 2,6-bis(4-diethylaminobenzylidene)cyclopentanone (DEAW), which is sensitive to 514 nm wavelength. The holographic gratings were fabricated successfully in these photopolymer samples by conventional optical interference method. We investigated the effect of dendrimer, either as a binder or as a plasticizer in the cellulose acetate butyrate (CAB), on the diffraction behavior. The addition of only 1 wt$\%$ of dendrimer-I into the CAB significantly increased the diffraction efficiency. The sample doped with dendrimer showed around 80-83$\%$ of the diffraction efficiency.

The Development of Science Education Program Based on Culturally Responsive Teaching

  • Chung, Choong-Duk;Kang, Kyung-Hee
    • Journal of The Korean Association For Science Education
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    • v.33 no.3
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    • pp.626-638
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    • 2013
  • The purpose of this study was to design a development frame for multicultural science program and develop a corresponding program using the frame. This study organized a development frame to design a multicultural science education program based on the culturally responsive teaching theory. This development frame consisted of the elements of purpose, teaching examples, teaching and learning methods, and assessment. This program consisted of the guideline for class teaching courses, reading materials, student worksheet, and teachers' reference materials. Based on this development frame, a multicultural science education program was developed, which was comprised of seven activities for elementary and middle school students. Each activity of the program included the concept and inquiry related to science education. In particular, by connecting the concept of science with the cultural characteristics of various countries, the activity made students aware of cultural diversity and the commonness of science principles. Compared to other subjects, the science education field has not actively undertaken studies on multicultural education. In term of dealing with universal principles, science education is suitable for making students aware of commonness. Accordingly, this gives rise to the need to draw cultural characteristics based on basic studies such as the analysis of science textbooks in various countries and develop culturally responsive programs utilizing the outcomes.

An Analysis of the Policy Effect on Institutionalization of Gender Responsive Budgeting - Focusing on World Bank 73 Countries - (성인지 예산 제도화의 정책적 효과 분석 - World Bank 73개 국가를 중심으로 -)

  • Hong, Heejeong;Hong, Sunghyun
    • International Area Studies Review
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    • v.22 no.3
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    • pp.29-66
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    • 2018
  • The purpose of the study was to point out the limitation of the conceptual discussions in which researches on gender responsive budgeting have remained so far and to empirically analyze the effect of institutionalization of gender responsive budgeting on the gender equality by using macro data. The units of the analysis were 73 countries which implements gender responsive budgeting among the 229 countries registered in the World Bank. Panel data were established on the materials of 7-year period from 2006 to 2012, which were analyzed by Fixed Effect Model. Gender Equality (Gender Gap Index) which is the ultimate goal of gender budgeting was established as the dependent variable while Institutionalization of Gender Responsive Budgeting (formal and qualitative classification) was established as the independent variable. In addition, social and economic factors, political factors and geographical factors which were judged to affect dependent variables were established as control variables. As a result of analysis, the institutionalization of gender responsive budgeting has positive effect on gender equality. Thus, the study confirmed that gender responsive budgeting has positive effect on gender equality in countries with legal, procedural and formal foundations rather than in countries with simple rhetoric in catchwords and documents. Moreover, the higher the level of institutionalization of gender responsive budgeting is, the more positive effect it has on the gender equality. Therefore, the study found out that efforts need to be accompanied to enhance the level of institutionalization in order to increase the effectiveness of institutionalization of gender responsive budgeting.