Layer-by-Layer Assembled Nano-Films for Controlled Release of Insulin Particle

XIANGDE LIN,홍진기 한국고분자학회 2015 한국고분자학회 학술대회 연구논문 초록집 Vol.2015 No.10

Organosilicate based superhydrophilic nanofilm with enhanced durability for dentistry application

Xiangde Lin,황보성희,정혜중,조영아,안효원,홍진기 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.36 No.-

The present work presents a layer-by-layer assembled nano-film with enhanced stability ontomouthguards for the first time. To obtain high thermal and mechanical durability of modifiedmouthguards, the silicon-based material, silsesquioxane and silica nanoparticle matrix (SiSQ), wasintroduced into nanofilms. Moreover, with the help of hydrogen-bonding interactions between SiSQ anda bio-compatible building block of branched polyethyleneimine (BPEI), (BPEI/SiSQ)n nanofilms weresuccessfully prepared. Anti-bacterial property of treated mouthguards is expected to be shown in termsof film superhydrophilicity. Above all, this organosilicate-based superhydrophilic nano-film withbiocompatibility and enhanced durability is of great significance, which can be applied to otherbiomedical platforms.

초젖음성 성질을 갖는 고안정성 나노필름

Xiangde Lin,황보성희,홍진기 한국막학회 2015 한국막학회 총회 및 학술발표회 Vol.2015 No.11

There have been many studies on superwetting surfaces, ranging from superhydrophilicity to superhydrophobicity, owing to the variety of their potential applications. There are some drawbacks to developing these films for certain applications, such as the fragility of the microscopic roughness feature that is vital to ensure superwettability. At the first part of in this presentation, we fabricated intrinsically stable superwetting films using the organosilicate based layer-by-layer (LbL) self-assembly method in order to control hierarchical roughness and adjusted the surface chemistry of the multilayer structures. At the second part, hydrophilic branched poly(ethylenimine) and nanoparticle were assembled into LbL multilayers in the presence of UV-curable poly(urethane acrylate).

The Durable Superhydrophobic Membranes for Oil/Water Separation: Learning from Nature

XIANGDE LIN,홍진기 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.2

Durable Superhydrophobic Mesh with Carbon Nanofibers Network Inlay-Gated Structure for High-Flux Water-in-Oil Emulsion Separation

Xiangde LIN,Junjira TANUM,Jinkee HONG 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.2

Mechanically durable superhydrophobic PDMS-candle soot composite coatings with high biocompatibility

Xiangde Lin,박소현,최다희,허지웅,홍진기 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.74 No.-

To realize practical applications, the development of superhydrophobic coatings with high durabilityagainst harsh environmental conditions has been of interest, especially coatings that are susceptible tomechanical damage. Herein, we present mechanically durable superhydrophobic polydimethylsiloxane(PDMS)-candle soot (CS)-based composite coatings through simple and rapid casting and soot processes,which can be fabricated on various substrates, such as glass, woods, stainless steel meshes, and plastics. The reported extremely water-repellent coatings consist of a PDMS basic binding layer, candle sootclusters (CSC), and an outside CS layer, which has exhibited long-lived superwettability and resistanceagainst mechanical damage in multi-cycle abrasion tests and ultrasonication treatments over a longduration. The resulting mechanical durability was mainly a result of three-dimensional topography-protected and carbon nanoparticle-mixed structures, which decreased the contact area and createdhighly hydrophobic bulk coatings. Moreover, the durable performances of the three types of CS-basedsuperhydrophobic coatings to resist mechanical damage, involving CS, PDMS-CS, and PDMS-CSC-CScoatings, were compared on a glass substrate, and the results indicated higher robustness of the presentPDMS-CSC-CS coatings. In addition, it showed higher biocompatibility than a PDMSfilm surface, and cantherefore be employed as a promising material for further modification for applications in prospectivemultifunctional biomedical devices.

Cobweb-inspired DNA-based membranes for multicomponent pollutant-oil-water emulsions separation

Lin, Xiangde,Heo, Jiwoong,Hong, Jinkee Elsevier 2018 Chemical engineering journal Vol.348 No.-

<P><B>Abstract</B></P> <P>Superwetting membranes are increasingly being applied in oil-water separation processes, especially for conventional immiscible mixtures, micro-emulsions, and nano-emulsions. However, in practical water purification processes, these mixtures usually contain other contaminated components, such as inorganic salts, nanoparticles, organic compounds, proteins, and bacteria. Herein, we report for the first time a superwetting membrane prepared from deoxyribonucleic acid (DNA)-based nanofibril materials for creating a multicomponent pollutant-oil-water filtration system. The development of such a system is challenging, considering that matter dispersed in the water phase must be separated by extra filtration process in conventional oil–water separations. The DNA-based membranes can be prepared with thicknesses as small as several tens of nanometers and transferred to a stainless steel mesh to form cobweb-inspired fibrous membranes. The resulting membranes can successfully filter nanoscale model molecules due to their cross-linked DNA fibril-based pores, and can separate oil-water emulsions because of their underwater superoleophobic/low-oil-adhesion properties. Thus, multicomponent pollutant-oil-water emulsions can be purified at a relatively low operation pressure, allowing the separation of water and other components with only one ultra-filtration membrane. The findings in the present work provide a completely novel route for addressing real-world oily wastewater or other mixtures with complicated compositions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A cross-linked DNA-based underwater superoleophobic membrane was subtly designed. </LI> <LI> The membrane showed size sieving effect, low-oil-adhesion, and swelling properties. </LI> <LI> It can be applied to challenging multicomponent pollutant-oil-water emulsions separation. </LI> <LI> The membranes can effectively purify small molecule contaminated oil-water emulsions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Simply realizing durable dual Janus superwettable membranes integrating underwater low-oil-adhesive with super-water-repellent surfaces for controlled oil–water permeation

Lin, Xiangde,Heo, Jiwoong,Choi, Moonhyun,Hong, Jinkee Elsevier 2019 Journal of membrane science Vol.580 No.-

<P><B>Abstract</B></P> <P>Janus wetting/non-wetting membranes are emerging asymmetric materials with opposing wettable interfacial properties. Because of the difference between the sides at an interface, they have been used in various practical applications such as unidirectional liquid transportation. However, newly developed Janus superwettable membranes are still highly desired and challenging, considering their conventional time-consuming preparation, oil-fouling contamination, and susceptible surface to mechanical damage. Herein, we propose a rapid and green fabrication method for durable dual Janus superhydrophilic (underwater superoleophobic)/superhydrophobic (superoleophilic) membranes, which integrate an underwater low-oil-adhesive with super-water-repellent surfaces for controlled oil–water permeation. The robust superhydrophilic and underwater superoleophobic surface can be rapidly created using a one-step chemical etching method. Then, underwater low-oil-adhesion is obtained for anti-oil-fouling. Moreover, a mechanically durable superhydrophobic coating with a super-water-repellent characteristic can be directly capped onto an etched stainless steel mesh (ESSM) through a rapid mechanical transferring process. Therefore, four kinds of wettable behaviors from one common interface can be readily realized for controlled oil–water permeation with an anti-oil-fouling property and high durability. The multifunctional membranes can combine superwettability-based oil–water separation and oil collection by a Janus membrane-based oil diode in the future. This will inspire the development of additional facial Janus superwettable membrane systems with extended applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dual Janus superwettable membranes were simply realized through a green method. </LI> <LI> The membranes combined underwater low-oil-adhesive and super-water-repellent surfaces. </LI> <LI> The as-prepared Janus superwettable membranes showed good mechanical durability. </LI> <LI> They can be well used for controlled oil-water permeation, separation, and collection. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Mechanically durable superhydrophobic PDMS-candle soot composite coatings with high biocompatibility

Lin, Xiangde,Park, Sohyeon,Choi, Daheui,Heo, Jiwoong,Hong, Jinkee THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2019 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.74 No.-

<P><B>Abstract</B></P> <P>To realize practical applications, the development of superhydrophobic coatings with high durability against harsh environmental conditions has been of interest, especially coatings that are susceptible to mechanical damage. Herein, we present mechanically durable superhydrophobic polydimethylsiloxane (PDMS)-candle soot (CS)-based composite coatings through simple and rapid casting and soot processes, which can be fabricated on various substrates, such as glass, woods, stainless steel meshes, and plastics. The reported extremely water-repellent coatings consist of a PDMS basic binding layer, candle soot clusters (CSC), and an outside CS layer, which has exhibited long-lived superwettability and resistance against mechanical damage in multi-cycle abrasion tests and ultrasonication treatments over a long duration. The resulting mechanical durability was mainly a result of three-dimensional topography-protected and carbon nanoparticle-mixed structures, which decreased the contact area and created highly hydrophobic bulk coatings. Moreover, the durable performances of the three types of CS-based superhydrophobic coatings to resist mechanical damage, involving CS, PDMS-CS, and PDMS-CSC-CS coatings, were compared on a glass substrate, and the results indicated higher robustness of the present PDMS-CSC-CS coatings. In addition, it showed higher biocompatibility than a PDMS film surface, and can therefore be employed as a promising material for further modification for applications in prospective multifunctional biomedical devices.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

On cliques and Lagrangians of hypergraphs

Qingsong Tang,Xiangde Zhang,Cheng Zhao 대한수학회 2019 대한수학회보 Vol.56 No.3

Given a graph $G$, the Motzkin and Straus formulation of the maximum clique problem is the quadratic program (QP) formed from the adjacent matrix of the graph $G$ over the standard simplex. It is well-known that the global optimum value of this QP (called Lagrangian) corresponds to the clique number of a graph. It is useful in practice if similar results hold for hypergraphs. In this paper, we attempt to explore the relationship between the Lagrangian of a hypergraph and the order of its maximum cliques when the number of edges is in a certain range. Specifically, we obtain upper bounds for the Lagrangian of a hypergraph when the number of edges is in a certain range. These results further support a conjecture introduced by Y. Peng and C. Zhao (2012) and extend a result of J. Talbot (2002). We also establish an upper bound of the clique number in terms of Lagrangians for hypergraphs.