Microfluidic approaches for the design of functional materials

Kang, Kyoung-Ku,Lee, Byungjin,Lee, Chang-Soo Elsevier 2018 MICROELECTRONIC ENGINEERING Vol.199 No.-

<P><B>Abstract</B></P> <P>Microfluidic systems, including microreactors, can precisely control an entire process and provide advantages, such as rapid mixing, fast heat and mass transfer due to miniaturization. Above all, the advantage of being easy to design and fabricate is the most attractive for the purposes of researchers. In the past two decades, it has become a research topic of great interest in the field of synthesis of chemicals and materials, due to these unique advantages. Furthermore, in recent years, studies are actively underway to design, construct, and compose the elements and functions of microfluidic devices for designing and synthesizing materials for specific applications or purposes. In this review, we will discuss the principles and forms of basic microfluidic devices, and discuss how microfluidic devices are used in the synthesis of polymeric and inorganic materials, particularly functional materials. Finally, we will present how microfluidic systems will be used in future materials research.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Introduction of considerations of design for droplet-based MF systems </LI> <LI> Description of representative MF systems and dimensionless numbers </LI> <LI> Review of the progress of MF system for functional materials synthesis </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis and characterization of hierarchical titanium-containing mesoporous materials with MFI crystalline structure using the gas phase recrystallization for the improvement of olefins epoxidation activity

Kang, Kyoung-Ku,Rhee, Hyun-Ku Elsevier 2018 Microporous and mesoporous materials Vol.257 No.-

<P><B>Abstract</B></P> <P>Here we propose the synthesis of hierarchically titanium-containing mesoporous materials with MFI crystalline structure through the effective and fast post recrystallization method. The post recrystallization method consists of two steps. The first step was the easy impregnation of the structure directing agent of MFI crystalline structure on calcined mesoporous materials. The second step was the fast steam assisted conversion (SAC) process. The mother supports (Ti-MCM-41 and Ti-SBA-15) are prepared using the modified hydrothermal synthesis method, and the SAC process is conducted using the fully dried tetrapropylammonium hydroxide impregnated mother supports under an autogenous steam pressure condition in an autoclave. The prepared materials are investigated using various characterization methods. The recrystallized mesoporous materials exhibit the MFI crystalline structure both in the pore as well as on the surface, and the Ti and Si species are rearranged on an atomic level. The mesoporosity is maintained depending on the SAC process time. The influences of the recrystallization are investigated using the olefins epoxidation. The recrystallization induces the increase of more active titanium species and the surface become more hydrophobic. These influences clearly reveal the improvements in the catalytic activity. The recrystallized mesoporous materials exhibit higher catalytic activity. The conversion and selectivity are improved and the side reactions are decreased significantly.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hierarchical titanium-containing mesoporous catalysts with MFI crystals are recrystallized using SAC process. </LI> <LI> The post recrystallization results in the rearrangement of the Ti and Si species on the atomic level. </LI> <LI> Recrystallized catalysts with MFI crystalline structures possess mesoporosity depending on the SAC process time. </LI> <LI> The catalysts with the hierarchical structure have excellent activity in the epoxidation reaction using hydrogen peroxide. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Elegant Approach to the Controllability of the Mechanical Properties of a Microgel via the Self-Assembly of Internal Molecules

Kang, Kyoung-Ku,Lee, Chang-Soo American Chemical Society 2018 ACS central science Vol.4 No.4

The Effects of Job Satisfaction and Organizational Commitment on Job Performance Ability of Female Employee in Bakery Company: Focusing on the Busan Area Bakery Company

Kyoung-Ku Kang 한국조리학회 2021 한국조리학회지 Vol.27 No.9

Synthesis of silica nanoparticles using biomimetic mineralization with polyallylamine hydrochloride

Kang, Kyoung-Ku,Oh, Hyun-Seok,Kim, Dong-Young,Shim, Gyurak,Lee, Chang-Soo Elsevier 2017 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.507 No.-

<P><B>Abstract</B></P> <P>To synthesize silica particles under mild conditions, we proposed a biomimetic synthesis method. The synthesis process was carried out based on a biphasic sol-gel synthesis method using TEOS (tetraethyl orthosilicate) as a silica source and PAH (polyallylamine) as a substitute for proteins of marine microorganisms for biosilicification. The function and activity of the PAH, used as a replacement for bioactive substances, were confirmed through comparisons between control experiments and designed experiments. The PAH exhibited the ability accelerate condensation with hydrolyzed TEOS in aqueous solutions. The PAH also exhibited high condensation activity in acidic and neutral conditions to produce silica particles. Moreover, PAH also created the nuclei of the silica particles, and the number of nuclei could be controlled by the concentration of PAH. In addition to exhibiting these unique capabilities, PAH did not generate any complexes or composites with the silica species. Depending on the synthesis conditions, the synthesized silica particles exhibited various shapes, such as sponge-like, self-assembled, irregular spherical and completely spherical shapes. The sizes of the primary particles were diverse, with a range from 10nm to 50nm. In particular, by adjusting the PAH concentration, it was possible to obtain nearly perfect spherical-shaped silica nanoparticles with uniform sizes, which has rarely been reported. Above all, using this paper, we can get closer to understanding the principles of silica formation using PAH as a replacement for the bioactive proteins of microorganisms.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spherical and monodispersed silica nanoparticles were synthesized by using PAH. </LI> <LI> PAH is strongly involved in nucleation and condensation reactions of silica. </LI> <LI> PAH can accelerate the nucleation and condensation of the hydrolyzed TEOS. </LI> <LI> PAH has a relatively very weak interaction with aqueous silicates. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

조리ㆍ제과제빵 대학생들의 교육환경이 교육만족도와 추천의도에 미치는 영향

강경구(Kyoung-Ku Kang) 한국조리학회 2016 한국조리학회지 Vol.22 No.8

THE HEATING COSTS SAVING EFFECTS OF AGRICULTURAL FACILITIES USING WASTE HEAT OF THE RESOURCE RECOVERY FACILITY

Youn Ku Kang,Jae Kyoung Jang,Jong Pil Moon,Jin Kyoung Kwon 한국신재생에너지학회 2015 AFORE Vol.2015 No.11

IPA기법을 활용한 요리대회의 차별화 전략과 품질 속성에 관한 연구: 조리·제과제빵 전공자를 중심으로

강경구(Kyoung-Ku Kang) 한국조리학회 2020 한국조리학회지 Vol.26 No.3

라이프스타일에 따른 해안가 베이커리카페 선택속성이 고객충성도에 미치는 영향

강경구(Kyoung-Ku Kang) 한국해양관광학회 2022 해양관광학연구 Vol.15 No.2

During the pandemic, daily life is expected to change significantly depending on lifestyles in a limited environment such as movement restrictions and social distancing. Seaside bakery cafes, centering on marine tourist destinations, raise expectations for differentiation not easily experienced in the city center. This study aims to suggest effective market segmentation and marketing strategies to managers by identifying various customer requirements and seeking strategic plans. First, the lifestyle group was divided into safety-seeking group, practicality seeking, and challenge-seeking group, and all groups showed differences in the selection attributes of bakery cafes. Second, the selection attributes of bakery cafes such as product, convenience, serviceability, and internal/external environment all had a significant effect on customer loyalty, and it was confirmed that internal/external environment had the highest influence. As a result of this study, it was confirmed that it is necessary to secure and develop attractive spatial characteristics according to the lifestyle of visitors. In other words, they prefer a practical, safe, healthy and convenient environment.

기능성 베이커리제품의 경험적가치가 고객만족과 재구매의도에 미치는 영향 : 해양관광도시 부산을 중심으로

강경구(Kang, Kyoung-ku) 한국해양관광학회 2021 해양관광학연구 Vol.14 No.3

The purpose of this study is to identify customer satisfaction and repurchase intentions for functional bakery products incorporating regional specialties of marine tourist destinations. It is a study on differentiation from existing products, characteristics of tourism products, improvement measures, and points for improvement. As a result of the study, Hypothesis 1 and Hypothesis 2 were accepted because economic value and cognitive value, which are sub-factors of the empirical value of functional bakery products, showed a significant positive (+) effect, but emotional value, social value, and rare value were rejected and partially adopted. As implications, through the consumption behavior of tourists, the economic value of “the functional products has excellent taste, worth the price, and differentiated from other products” and the cognitive value “various and interesting stories and new facts about functional products, it was a new experience.” affects customer satisfaction and repurchase intention