• Title, Summary, Keyword: surface modification

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Surface modification of polymeric membranes for low protein binding

  • Higuchi, Akon;Tamai, Miho;Tagawa, Yoh-Ichi;Chang, Yung;Ling, Qing-Dong
    • Membrane Water Treatment
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    • v.1 no.2
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    • pp.103-120
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    • 2010
  • Surface modification of microfiltration and ultrafiltration membranes has been widely used to improve the protein adsorption resistance and permeation properties of hydrophobic membranes. Several surface modification methods for converting conventional membranes into low-protein-binding membranes are reviewed. They are categorized as either physical modification or chemical modification of the membrane surface. Physical modification of the membrane surface can be achieved by coating it with hydrophilic polymers, hydrophilic-hydrophobic copolymers, surfactants or proteins. Another method of physical modification is plasma treatment with gases. A hydrophilic membrane surface can be also generated during phase-inverted micro-separation during membrane formation, by blending hydrophilic or hydrophilic-hydrophobic polymers with a hydrophobic base membrane polymer. The most widely used method of chemical modification is surface grafting of a hydrophilic polymer by UV polymerization because it is the easiest method; the membranes are dipped into monomers with and without photo-initiators, then irradiated with UV. Plasma-induced polymerization of hydrophilic monomers on the surface is another popular method, and surface chemical reactions have also been developed by several researchers. Several important examples of physical and chemical modifications of membrane surfaces for low-protein-binding are summarized in this article.

Effect of Surface Modification Process Conditions on Properties of Aramid Paper (아라미드 종이의 특성에 대한 표면 개질 과정 조건의 영향)

  • Sha, Lizheng;Zhao, Huifang
    • Polymer Korea
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    • v.37 no.2
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    • pp.196-203
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    • 2013
  • Surface modification of meta-aramid fibers was performed by phosphoric acid treatment. Surface morphology and element composition of untreated and treated fibers were analyzed by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Effects of surface modification on the mechanical strength of aramid papers made from meta-aramid fibers and fibrid were investigated. Surface modification conditions were optimized by response surface analysis (RSA). Results show that phosphoric acid treatment increases the surface roughness and oxygen content of aramid fibers. They improve the interface bonding strength between aramid fibers and fibrid, which improves the tensile strength of aramid papers. The results of response surface analysis indicate that the tensile strength of aramid papers increases by 47.5% and reaches the maximum when meta-aramid fibers are treated with 21.1wt% phosphoric acid solution at $39.3^{\circ}C$ for 36.7 min.

Advanced Surface Modification Techniques for Enhancing Osseointegration of Titanium Implant (임상가를 위한 특집 1 - 티타늄 임플란트의 골융합 증진을 위한 최신 표면처리 기술)

  • Song, Ho-Jun
    • The journal of the Korean dental association
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    • v.48 no.2
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    • pp.96-105
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    • 2010
  • Titanium implant is used as the most popular dental material for replacement of missing teeth recently. A lot of studies on the surface modification of titanium implant have been carried out for enhancing osseointegration. The surface modification techniques could be classified as follows; topographic modifications which provide roughness and porosity, chemical surface modificationss or deposition of osseoconductive materials, and biochemical modifications to immobilize bone growth factors on titanium surface. In this study, the current and ongoing surface modification techniques and its typical characteristics used in clinics were reviewed. In the future, study and implication about biochemical modifications including patient' s individual characteristics will be important.

A Rapid Local Modification Algorithm for NURBS surface (NURBS 곡면의 고속 부분 수정 알고리듬 개발)

  • 김호찬;최홍태;김준안;이석희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1402-1405
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    • 2004
  • Algorithms on modification of NURBS surface requires modeling history to change its boundary conditions. The history is stored when the surface is modeled and saved in the corresponding model file. But when the model is transferred to other systems the history generally cannot be recognized. So modification algorithms without history is highly required. Previous works on the field is concentrated in the point based modification without any restriction condition. Therefore this study is intended to develope a curved based modification algorithm with restriction conditions. A rapid modification algorithm is suggested, implemented and tested.

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A Study on the Ultrasonic Nano Crystal Surface Modification(UNSM) Technology and It's Application (초음파 나노표면개질기술의 특성과 활용방안 연구)

  • Pyoun, Young-Sik;Park, Jeong-Hyeon;Cho, In-Ho;Kim, Chang-Sik;Suh, Chang-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.3
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    • pp.190-195
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    • 2009
  • All the failure in fatigue of torsion, bending and rolling contact, and in sliding wear begins mostly from surface. So much efforts have been invested to the surface technology which deal these problems during past decades, but the industrial demand keeps growing and more significant requirements are added to researchers and engineers. Nano crystal surface modification technology which makes the surface layers into nano crystalline, induces big and deep compressive residual stress, increases surface hardness, improves surface hardness, and make micro dimples structure on surface is an emerging technology which can break limits of current surface technology and relieve the burden of researchers and engineers. In this study, a nano crystal surface modification technology which is calling UNSM(Ultrasonic nano crystal surface modification) technology, is introduced and how it has been applied to industry to solve these failure problems is explained.

Surface modification of Aluminum for mold by nitrogen ion implantation (질소이온주입에 의한 금형용 알루미늄의 표면개질특성)

  • 강혁진;안성훈;김경동;이재상;이재형
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.254-259
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    • 2004
  • The research on surface modification technology has been advanced to change the properties of engineering material. Ion implantation is a novel surface modification technology to enhance the mechanical, chemical and electronic properties of mechanical parts. In this research, nitrogen ions are implanted into aluminum for mold to improve endurance and life span. To analyze modification of surface properties, micro hardness, friction coefficient, wear resistance, contact angle, and surface roughness were measured. Hardness of ion implanted specimens was higher than untreated specimen and friction coefficient was also improved. In this experiment, it can be expected that nitrogen ion implantation can contribute to enhance the mechanical properties of material and ion implantation technology may also be applied to other materials.

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Modification methods of polyethersulfone membranes for minimizing fouling - Review

  • Sathish Kumar, R.;Arthanareeswaran, G.;Paul, Diby;Kweon, Ji Hyang
    • Membrane Water Treatment
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    • v.6 no.4
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    • pp.323-337
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    • 2015
  • Membrane Fouling was considered as major drawback in various industrial applications. Thus, this paper reviews the surface modification of polyethersulfone (PES) membranes for antifouling performance. Various modification techniques clearly indicate that hydrophilicity has to improve on the PES membrane surface. Moreover, the mechanism of fouling reduction with corresponds to various modification methods is widely discussed. Incorporation of hydrophilic functional groups on PES membrane surface enhances the surface free energy thereby which reduces the fouling. Characterization techniques adopted for the surface modified membranes was also discussed. These studies might be useful for the other researchers to utilize the modification technique for the applications of waste water treatment, chemical process industry and food industry.

Surface Modification of Polymethyl methacrylate(PMMA) by Laser Surface Treatment for Microfluidic Chip (유체소자 성능향상을 위한 Polymethyl methacrylate(PMMA)의 레이저 표면처리)

  • Shin, Sung-Kwon;Lee, Sang-Don;Lee, Cheon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.2
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    • pp.334-337
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    • 2007
  • After the advent of micro-Total Analysis Systems(${\mu}-TAS$) based on silicon various polymer for microfluidic chip has been studied. Polymer materials for microfluidic compared with silicon and glass which were traditional materials of a microfluidic chip, have the advantages of economical efficiency simple manufacturing process and wide materials selectivity corresponding to fluids. Surface energy of polymers we, however lower than silicon or glass. To overcome this problem, various surface modification methods have been investigated. The surface modification using laser has the advantage of the simple experiment that only directly irradiated laser beam on the material surface in the air. This work discuss the surface modification of polymethly methacrylate(PMMA) by 4th harmonic Nd:YAG laser (${\lambda}266nm$, pulse) treatment. After the laser treatment, the PMMA surface was investigated using a contact angle measuring instrument. The contact angle was decreased with a increase of the surface oxygen content. This result means the surface energy of PMMA was increased by the laser treatment without changing of its bulk characteristics.

Bio-Inspired Surface Modification of 3-Dimensional Polycaprolactone Scaffold for Enhanced Cellular Behaviors

  • Jo, Seon-Ae;Gang, Seong-Min;Park, Su-A;Lee, Hae-Shin
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.202-202
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    • 2011
  • The research of 3-dimensional (3-D) scaffold for tissue engineering has been widely investigated as the importance of the 3-D scaffold increased. 3-D scaffold is needed to support for cells to proliferate and maintain their biological functions. Furthermore, its architecture defines the shape of the new bone and cartilage growth. Polycaprolactone (PCL) has been one of the most promising materials for fabricating 3-D scaffold owing to its excellent mechanical property and biocompatibility. However, there are practical problems for using it, in vitro and in vivo; extracellular matrix components and nutrients cannot penetrate into the inner space of scaffold, due to its hydrophobic property, and thus cell seeding and attachment onto the inner surface remain as a challenge. Thus, the surface modification strategy of 3-D PCL scaffold is prerequisite for successful tissue engineering. Herein, we utilized a mussel-inspired approach for surface modification of 3-D PCL scaffold. Modification of 3-D PCL scaffolds was carried out by simple immersion of scaffolds into the dopamine solution and stimulated body fluid, and as a result, hydroxyapatite-immobilized 3-D PCL scaffolds were obtained. After surface modification, the wettability of 3-D PCL scaffold was considerably changed, and infiltration of the pre-osteoblastic cells into the 3-D scaffold followed by the attachment onto the surface was successfully achieved.

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Effect of Two-step Surface Modification of Activated Carbon on the Adsorption Characteristics of Metal Ions in Wastewater I. Equilibrium and Batch Adsorptions

  • Park, Geun-Il;Lee, Jae-Kwang;Ryu, Seung-Kon;Kim, Joon-Hyung
    • Carbon letters
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    • v.3 no.4
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    • pp.219-225
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    • 2002
  • The two-step surface modifications of activated carbon was carried out to improve the adsorption capacity of toxic heavy metal ions in liquid phase. Physical and chemical properties of the as-received activated carbon (AC) and two kinds of surface-modified activated carbons ($1^{st}AC$ and $2^{nd}AC$) were evaluated through the BET analysis, surface acidity, and oxides measurements. Specific surface area and pore volume did not significantly change, but surface oxide-group remarkably increased by the surface modification. Equilibrium and batch adsorptions of the various metals, such as Pb, Cd, and Cr, using AC, $1^{st}AC$, and $2^{nd}AC$ were performed at initial pH 5. The adsorption capacity and rate of $2^{nd}AC$ were higher than those of AC and $1^{st}AC$. The carboxylic/sodium carboxylate complex groups were developed from the two-step surface modification of activated carbon, which strongly affected the adsorption of metal ions.

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