• Title, Summary, Keyword: silanization reaction

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Quantitative Analysis of the Degree of Silanization by the Ninhydrin Method and its Application to the Immobilization of GL-7-ACA Acylase and Cellulolytic Enzyme

  • Park, Seung-Won;Kim, Yong-In;Chung, Koo-Hun;Kim, Seung-Wook
    • Journal of Microbiology and Biotechnology
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    • v.11 no.2
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    • pp.199-203
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    • 2001
  • A simple quantitative method to measure the degree of silanization was developed, based on the reaction of ninhydrin with the silanization reagent (3-aminopropyltriethoxysilane, 3-APTES). At low concentrations (0.001-0.005%, v/v) of 3-APTES, a good linearity was obtained when 3-APTES reacted with undiluted ninhydrin for 30 min. On the other hand, at high levels of 3-APTES, a linearity was obtained when 3-APTES reacted with 3-fold diluted ninhydrin for 20 min. The reliability of regression curves mentioned above was expressed as a regression coefficient ($R^2$) of more than 0.99. Immobilization of different enzymes was introduced via silanization by using the 3-APTES in order to confirm the validity of the ninhydrin method. When yield for each step in the immobilizatio process were compared, yields of both glutaraldehyde and protein were founc to have the same tendency to silanization. These results shw that the ninhydrin method was suitable for quatitative analysis of silanization and that yields of immobilization could be pre-estimated by measuring silanization levels using the ninhydrin method.

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Effect of 1,3-Diphenyl-guanidine (DPG) Mixing Step on the Properties of SSBR-silica Compounds

  • Lim, Seok-Hwan;Lee, Sangdae;Lee, Noori;Ahn, Byeong Kyu;Park, Nam;Kim, Wonho
    • Elastomers and Composites
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    • v.51 no.2
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    • pp.81-92
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    • 2016
  • 1,3-Diphenylguanidine (DPG) is commonly used as a secondary accelerator which not only acts as booster of cure but also activating silanization reaction. The aim of this study is to increase the interaction between silica and rubber by using DPG. In this study, mixing was proceeded in two steps. The T-1 compound is mixed DPG with silica and silane coupling agent in the kneader at high temperature which is named as $1^{st}$ mixing step. T-3 compound is mixed DPG with curatives in the two-roll mill at low temperature which is named as $2^{nd}$ mixing step. The T-2 compound is mixed a half of DPG in $1^{st}$ mixing step and the remainder is mixed in $2^{nd}$ mixing step. Total DPG content was equal for all compounds. When DPG is mixed with silica, silane coupling agent during the $1^{st}$ mixing step, a decrease in cure rate and an increase in scorch time can be seen. This indicates that DPG is adsorbed on the surface of silica. during rubber processing. However, bound rubber content is increased and dynamic properties are improved. These results are due to the highly accelerated silanization reaction. However, there are no significant difference in 100%, 300% modulus.

Quantitative Analysis of Silanization Degree of Silica Nanoparticles Modified with Bis[3-(trimethoxysilyl)propyl]amine Coupling Agent (Bis[3-(trimethoxysilyl)propyl]amine 커플링제로 개질된 실리카 나노입자의 실란화도 정량 분석)

  • Jeon, Ha-Na;Kim, Jung-Hye;Ha, Ki-Ryong
    • Polymer(Korea)
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    • v.36 no.3
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    • pp.372-379
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    • 2012
  • In this study, we treated silica nanoparticles with bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify their surfaces. We investigated the effects of BTMA hydrolysis time, BTMA concentration and BTMA treatment time on the degree of silanization reaction of silica nanoparticles. We used Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to obtain quantitative data. We found the decrease of isolated Si-OH peak intensity at 3747 $cm^{-1}$ and the increase of $-CH_2 $stretching and bending peaks with increasing hydrolysis time, concentration and treatment time of BTMA. EA analysis results also supported this trend. We found a strong effect of BTMA concentration on the degree of silanization of the silica particles, but weak effects of the hydrolysis time and the treatment time.

Microenvironmental Optimizaton of Immobilized Invertase for Methyl- $\beta$ -D-Fructofuranoside Synthesis (Methyl- $\beta$ -D-Fructofuranoside 합성을 위한 고정화 전화당 효소의 미소환경 최적화)

  • 허주형;안형환
    • Journal of the Korea Safety Management & Science
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    • v.1 no.1
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    • pp.259-272
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    • 1999
  • In order to enhance the selectivity, productivity and yield of methyl fructoside, which was synthesized by enzymatic glycosylation of sucrose and methanol solution, controlling of surface property of solid support using different immobilization procedures optimized microenvironment of immobilized invertase. Silanization and polyethylene imine coating methods were adopted to give a hydrophobic and hydrophilic environment of immobilized invertase. As a result, polyethyleneimine coating method gave higher loading of enzyme, effective activity, and relative activity than silanization method, because it brought on increasing the functional density of amino group and enhancing the conservation of activity by regulating of hydrophilicity. And then, hydrophilic environment was possible to restraint the assessing of methyl fructoside molecule, which was more hydrophobic than sucrose, fructose, and glucose molecule in the reaction mixture, into .the active site of immobilizedinvertase. Consequently, hydrophilic microenvironment of immobilized invertase by polyethyleneimine coating obtained higher yield and productivity with increasing conversion than silanized and native invertase. Thus, this procedure optimized the microenvironment of immobilized invertase suitable for the enzymatic synthesis of methyl fructoside.

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Effects of Silane Coupled Silica on the Pysical Properties of Synthetic Rubber Compounds (실란 커프링제로 처리된 실리카가 합성고무 배합물의 물리적 특성에 미치는 영향)

  • Lee, Seag
    • Elastomers and Composites
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    • v.33 no.3
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    • pp.185-192
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    • 1998
  • This study was investigated on the physical properties of synthetic rubber compounds containing silica and silane copuled silica. Surface area and pore volume of silane copuled silica appeared to be low compared with those of pure silica because silane coupling agent blocks the pore of silica surface during silanization reaction. Silica with large surface area and high structure showed the short scorch time$(t_5)$ and rapid cure rate. The silane coupled silica showed the shorter scorch time and more rapid cure rate than pure silica because of the of effect of sulfur in the silane coupling agent(Si 69), The high value of $N_2SA$ minus CTAB com-pared with surface area and structure of silica showed the high 300% modulus. Also, the surface area and structure of silica did not affected the amount of PICO loss that indicate the abrasion resistance but affected the amount of cut and chip loss.

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Spectroscopic Studies on the Reaction between Amino Groups on Silica Nanoparticle Surface and Glycidyl Methacrylate (실리카 나노입자 표면에 결합된 아미노기와 Glycidyl Methacrylate의 반응에 관한 분광학적 연구)

  • Lee, Sangmi;Ha, KiRyong
    • Polymer(Korea)
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    • v.37 no.6
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    • pp.777-783
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    • 2013
  • We used dipodal type bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify silica nanoparticles to introduce secondary amino groups on the silica surface. These grafted N-H groups were reacted with glycidyl methacrylate (GMA) to introduce polymerizable methacrylate groups on the silica surface. After modification reaction, we used several analytical techniques such as Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state $^{13}C$ cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to analyze the effects of reaction time, reaction temperature and used GMA concentration on the modification degree between N-H groups on the silica surface and epoxide groups of GMA. We found increased introduction of methacrylate groups on the silica surface by ring opening reaction of epoxide groups of GMA with N-H groups on BTMA treated silica with increased reaction time, reaction temperature and used GMA concentration within our experimental conditions.

Quantitative Analysis of Grafted Methacrylate Groups by Michael Addition Reaction between Primary and Secondary Amino Groups on the Silica Nanoparticle Surface with 3-(Acryloyloxy)-2-Hydroxypropyl Methacrylate (실리카 나노 입자 표면에 결합된 1차 및 2차 아미노기와 3-(Acryloyloxy)-2-hydroxypropyl Methacrylate의 마이클 부가 반응에 의해 도입되는 메타크릴레이트기의 정량적 분석)

  • Lee, Sangmi;Ha, KiRyong
    • Polymer(Korea)
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    • v.39 no.2
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    • pp.300-310
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    • 2015
  • In this study, we modified silica nanoparticles with N-[3-(trimethoxysilyl)propyl]ethylenediamine (TPED) silane coupling agent, which has one primary and one secondary amino groups in a molecule, to introduce amino groups on the silica surface. After modification of silica, we used 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) to introduce methacrylate groups by Michael addition reaction. We found about 30% of N-H groups on the TPED modified silica surface reacted with acrylate groups of AHM compared to about 85% of reaction between N-H groups of pure TPED with acrylate groups of pure AHM. This lower degree of Michael addition reaction for heterogeneous reaction between N-H groups on the solid TPED modified silica and liquid AHM compared to homogeneous reaction between pure liquid TPED and pure liquid AHM may be caused by lower mobility of grafted amino groups of TPED moiety and higher steric hindrance caused by solid silica particles.

Surface Modification of Microcrystalline Cellulose (MCC) Filler for CO2 Capture (CO2 흡착 충전제 제조를 위한 microcrystalline cellulose (MCC) 입자 표면개질연구)

  • Yang, Yeokyung;Park, Seonghwan;Kim, Hanna;Hwang, Ki-Seob;Ha, KiRyong
    • Korean Chemical Engineering Research
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    • v.55 no.1
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    • pp.60-67
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    • 2017
  • In this study, we performed surface modification of biodegradable microcrystalline cellulose (MCC) to use as a filler in polyethylene (PE) composite in food packaging application. We modified MCC surface with (3-trimethoxysilylpropyl)diethylenetriamine (TPDT) silane coupling agent, which has one primary amino group and two secondary amino groups per molecule, to introduce amino groups with a carbon dioxide adsorption capability in MCC. Effects of each of the reaction conditions such as amount of TPDT introduced, swelling time, reaction temperature, and reaction time on surface modification degree of MCC were investigated by changing a variety of above reaction conditions. The amount of TPDT grafted on MCC surface and formation of chemical bonds were confirmed by Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and solid state $^{29}Si$ nuclear magnetic resonance (NMR) spectroscopy. We confirmed increase of grafted amount of TPDT on MCC with increasing reaction time, reaction temperature, and amount of introduced TPDT.

Synthesis and Characterization of Magnetic Nanoparticles and Its Application in Lipase Immobilization

  • Xu, Jiakun;Ju, Caixia;Sheng, Jun;Wang, Fang;Zhang, Quan;Sun, Guolong;Sun, Mi
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2408-2412
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    • 2013
  • We demonstrate herein the synthesis and modification of magnetic nanoparticles and its use in the immobilization of the lipase. Magnetic $Fe_3O_4$ nanoparticles (MNPs) were prepared by simple co-precipitation method in aqueous medium and then subsequently modified with tetraethyl orthosilicate (TEOS) and 3-aminopropyl triethylenesilane (APTES). Silanization magnetic nanoparticles (SMNP) and amino magnetic nanomicrosphere (AMNP) were synthesized successfully. The morphology, structure, magnetic property and chemical composition of the synthetic MNP and its derivatives were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) analysis, X-ray diffraction, superconducting quantum interference device (SQUID) and thermogravimetric analyses (TGA). All of these three nanoparticles exhibited good crystallization performance, apparent superparamagnetism, and the saturation magnetization of MNP, SMNP, AMNP were 47.9 emu/g, 33.0 emu/g and 19.5 emu/g, respectively. The amino content was 5.66%. The AMNP was used to immobilize lipase, and the maximum adsorption capacity of the protein was 26.3 mg/g. The maximum maintained activity (88 percent) was achieved while the amount of immobilized lipase was 23.7 mg $g^{-1}$. Immobilization of enzyme on the magnetic nanoparticles can facilitate the isolation of reaction products from reaction mixture and thus lowers the cost of enzyme application.

Spectroscopic Analysis on Michael Addition Reaction of Secondary Amino Groups on Silica Surface with 3-(Acryloyloxy)-2-hydroxypropyl Methacrylate (2차 아미노기가 결합된 실리카 나노 입자 표면에 3-(Acryloyloxy)-2-hydroxypropyl Methacrylate의 마이클 부가 반응에 대한 분광학적 분석)

  • Lee, Sangmi;Ha, Ki Ryong
    • Polymer(Korea)
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    • v.38 no.2
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    • pp.257-264
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    • 2014
  • In this study, we modified silica nanoparticles with bis[3-(trimethoxysilyl)propyl]ethylenediamine (BTPED) silane coupling agent, which has two secondary amino groups in a molecule, to introduce amino groups on the silica surface. After modification of silica, we used acrylate group containing 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) to introduce polymerizable methacrylate groups by Michael addition reaction. We used Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and liquid and solid state cross polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to understand the reactions between N-H groups of BTPED modified silica surface and acrylate groups of AHM monomer. We confirmed Michael addition reaction between BTPED modified silica and AHM completed in 2 hr reaction time. We also found increased methacrylate group introduction with increase of mol ratio of the acrylate group of AHM to N-H group of BTPED modified silica by increase of C=O peak area of measured FTIR spectra. These results were also supported by EA and solid state $^{13}C$ and $^{29}Si$ NMR results.