상수 공업용수 및 하천수를 활용한 균일한 실리카 나노입자 합성 및 전기감응형 스마트유체로의 응용

김하영,제갈석,이능히,사민기,김동현,김민상,김지원,윤창민 유기성자원학회 2023 유기물자원화 Vol.31 No.1

This study describes the successful synthesize strategy for the silica nanoparticles utilizing various water sources, including tap, industrial, and stream waters without using deionized water. Also, as-synthesized silica nanoparticles are employed as dispersive materials for the electro-responsive smart fluid application. Specifically, homogeneous silica nanoparticles with sizes of 500–700nm are successfully prepared in large scale at once (ca. 12.0 g) with the described experimental method and showing similar structural and chemical characteristics with silica nanoparticles synthesized using the deionized water. The size of silica nanoparticles are varied according to the ion conductivity differences of tap, industrial, stream water, and deionized water. The size of silica nanoparticles decresed with the increased ion conductivity, indicating the ion suppression of growth of silica nanoparticles. Moreover, as-synthesized silica nanoparticles from various water sources of electro-responsive characteristic are investigated by the smart fluid application. The smart fluids containing silica nanoparticles synthesized by tap, industrial, and stream water exhibited higher shear stress compared to the deionized water, owing to the more rigid fibril-like structures formed by the smaller silica nanoparticles. Conclusively, uniform silica nanoparticles from various water sources without any purification are able to successfully prepared without usage of deionized water and resulting silica nanoparticles manifested higher electro-responsive performance. 본 연구에서는 증류수를 사용하지 않고 상수, 공업용수 및 하천수를 활용하여 균일한 실리카 나노입자를성공적으로 제조하는 방법에 대해 제시하였다. 또한, 제조된 실리카 나노입자들은 전기감응형 스마트유체의 분산물질로 적용하였다. 상세히는, 다양한 종류의 물을 사용하여 500–700nm 사이즈의 실리카 나노입자를 한 번의 실험으로 대량 제조(약 12.0g) 하였으며 증류수를 활용하여 합성한 750nm 사이즈의 실리카 나노입자와 동일한 형태학적화학적 특성을 가지고 있음을 확인하였다. 다양한 물을 사용하여 제조한 실리카 나노입자의 사이즈는 이온전도도에 따라 변화하였다. 이온전도도가 높으면 높을수록 제조된 실리카 나노입자의 크기가 작아짐을 확인할 수 있었고, 이는 이온들이 실리카 나노입자의 성장을 억제하기 때문이다. 또한, 제조한 실리카 나노입자들을 전기감응형 스마트유체로 응용하였다. 그 결과, 상수, 공업용수 및 하천수를 활용하여 제조한 실리카 나노입자가 증류수를 활용하여합성한 실리카 나노입자 대비 높은 전단응력을 나타냄을 확인할 수 있었고, 이는 작은 사이즈의 실리카 나노입자가전기장 하에서 더 강한 사슬 구조를 형성하기 때문이다. 결론적으로, 본 연구를 통해 다양한 물을 증류수와 같이정제하지 않고 사용하여 실리카 나노입자를 성공적으로 제조할 수 있음을 확인하였고, 해당 입자들이 전기감응형스마트유체 응용에서 우수한 성능을 나타냄을 확인할 수 있었다.

Photocuring kinetics of UV-initiated free-radical photopolymerizations with and without silica nanoparticles

Cho, Jung-Dae,Ju, Hyoung-Tae,Hong, Jin-Who Wiley Subscription Services, Inc., A Wiley Company 2005 Journal of polymer science Part A, Polymer chemist Vol.43 No.3

<P>We used photodifferential scanning calorimetry to investigate the photocuring kinetics of UV-initiated free-radical photopolymerizations of acrylate systems with and without silica nanoparticles. Two kinetics parameters—the rate constant (k) and the order of the initiation reaction (m)—were determined for hybrid organic–inorganic nanocomposite systems containing different amounts of added silica nanoparticles (0–20 wt %) and at different isothermal temperatures (30–100 °C) using an autocatalytic kinetics model. The kinetic analysis revealed that the silica nanoparticles apparently accelerate the cure reaction and cure rate of the UV-curable acrylate system, most probably due to the synergistic effect of silica nanoparticles during the photopolymerization process. However, a slight decrease in polymerization reactivity that occurred when the silica content increased beyond 15 wt % was attributed to aggregation between silica nanoparticles. We also observed that the addition of silica nanoparticles lowered the activation energy for the UV-curable acrylate system, and that the collision factor for the system with silica nanoparticles was higher than that obtained for the system without silica nanoparticles, indicating that the reactivity of the former was greater than that of the latter. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 658–670, 2005</P> <B>Graphic Abstract</B> <P>Photodifferential scanning calorimetry was used to investigate the photocuring kinetics of UV-initiated free-radical photopolymerizations of acrylate systems with and without silica nanoparticles. Two kinetics parameters—the rate constant (k) and the order of the initiation reaction (m)—were determined for hybrid organic-inorganic nanocomposite systems containing different amounts of added silica nanoparticles (0–20 wt %) and at different isothermal temperatures (30–100 °C) using an autocatalytic kinetics model. The kinetic analysis revealed that the silica nanoparticles apparently accelerate the cure reaction and cure rate of the UV-curable acrylate system, most probably due to the synergistic effect of silica nanoparticles during the photopolymerization process. However, a slight decrease in polymerization reactivity that occurred when the silica content increased beyond 15 wt % was attributed to aggregation between silica nanoparticles. <img src='wiley_img/0887624X-2005-43-3-POLA20529-gra001.gif' alt='wiley_img/0887624X-2005-43-3-POLA20529-gra001'> </P>

Effect of surface modification of silica nanoparticles by silane coupling agent on decontamination foam stability

Sonn, Jong Suk,Lee, Ju Yeon,Jo, Seon Hui,Yoon, In-Ho,Jung, Chong-Hun,Lim, Jong Choo Elsevier 2018 Annals of nuclear energy Vol.114 No.-

<P><B>Abstract</B></P> <P>The effect of surface modification of silica nanoparticles by Dimethyldichlorosilane (DMDCS) on decontamination foam stability was investigated by the measurement of decaying foam volume with time using a Foamscan. The hydrophobicity of silica nanoparticles modified by DMDCS was characterized by active ratio via a floating test and contact angle analysis. Contact angle measurement has shown that silica nanoparticles surface become more hydrophobic as DMDCS concentration increases. Foam stability test in unmodified silica particles-surfactant mixtures revealed that silica nanoparticles-surfactant stabilized foams are much more stable than surfactant-stabilized foams and certain level of surfactant concentration is required for the synergy between silica nanoparticle and surfactant. In foam stability test with modified silica particle-surfactant mixtures, it was found that silica nanoparticles with the proper level of hydrophobicity shows the best performance in foam stability and this result was supported by optical and fluorescence microscope images.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Surface modification of silica nanoparticles was characterized by active ratio. </LI> <LI> Effect of surface modified silica nanoparticles on foam stability was investigated. </LI> <LI> Foam stability was identified through optical and fluorescence microscope images. </LI> </UL> </P>

Fabrication of Nearly Monodispersed Silica Nanoparticles by Using Poly(1-vinyl-2-pyrrolidinone) and Their Application to the Preparation of Nanocomposites

Chung, You-Sun,Jeon, Mi-Young,Kim, Chang-Keun The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.1

To fabricate dental nanocomposites containing finely dispersed silica nanoparticles, nearly monodispersed silica nanoparticles smaller than 25 nm were synthesized without forming any aggregates via a modified sol-gel process. Since silica nanoparticles synthesized by the Stober method formed aggregates when the particle size is smaller than 25 nm, the synthetic method was modified by changing the reaction temperature and adding poly(1-vinyl-2-pyrrolidinone) (PVP) to the reaction mixture. The size of the formed silica nanoparticles was reduced by increasing the reaction temperature or adding PVP. Furthermore, the formation of aggregates with primary silica nanoparticles smaller than 25 nm was prevented by increasing the amount of PVP added to the reaction mixture. To enhance the dispersion of the silica particles in an organic matrix, the synthesized silica nanoparticles were treated with 3-methacryloxypropyltrimethoxysilane ($\gamma$-MPS). A dental nanocomposite containing finely dispersed silica nanoparticles could be produced by using the surface-treated silica nanoparticles.

Surface properties of silica nanoparticles modified with polymers for polymer nanocomposite applications

Youngchan Shin,Deokkyu Lee,이강택,안경현,김범상 한국공업화학회 2008 Journal of Industrial and Engineering Chemistry Vol.14 No.4

The surface of silica nanoparticles was modified with poly(ethylene glycol) methacrylate (PEGMA) or poly(propylene glycol) methacrylate (PPGMA) in order to improve the dispersion of nanoparticles in a polymer matrix. Nanosized silica particles were synthesized by the Sto¨ber method with tetraethyl orthosilicate (TEOS). Silica nanoparticles were treated with triethoxyvinylsilane (VTES) as a coupling agent to introduce reactive groups and the PEG or PPG were then grafted onto the particle surface via UV-photopolymerization. Various analytical methods, i.e., scanning electron microscopy (SEM), thermogravimetry (TG), zeta potential measurement, and water vapor adsorption measurement were used to comprehensively characterize the unmodified(pure) and modified silica particles. The SEM images of the pure and modified particles demonstrated that both particles have a spherical shape and a uniform size without agglomeration. The silica particles modified with polymers showed higher weight loss than unmodified silica particles because of the decomposition of the organic polymers grafted onto the particles. The surface modification of silica particles with polymers decreased the zeta potential values of the silica surface. Modified silica particles had lower water vapor adsorption due to the hydrophobic surface property resulting from the polymers grafted onto the silica surface. In addition, we have developed an electrical conductivity measurement as a novel method to analyze the surface properties of silica nanoparticles. The modified silica particles had lower electrical conductivity than that of unmodified silica particles.

Gene expression profiling associated with treatment of positive charged colloidal silica nanoparticle in human neuroblastoma cells

김지희,박희옥,장석원,신차균,류재천,김연정,양성익 한국바이오칩학회 2011 BioChip Journal Vol.5 No.4

Among the physico-chemical properties of nanoparticles, surface chemistry is one of the most important factors in cytotoxicity or cellular injurious effects of nanoparticles. However, the role of specific surface chemistry involved in the intracellular responses is not well understood. We investigated the comprehensive gene expression profile of biological responses of commercially available colloidal silica nanoparticles with different charge in human neuronal cell line, SHSY5Y. Positive charged silica CL nanoparticle showed less cytotoxicity than negative charged silica AM at more than 200 ppm. At 100 ppm, however, both positive and negative charged silica nanoparticles gave rise to low cytotoxicity. On the other hand, transcriptional changes by these silica nanoparticles represented that positive charged silica CL affected to much more genes than negative charged silica AM. Through gene ontology (GO) analysis, we identified that positive charged silica CL nanoparticle affected to the receptor mediated cellular responses, organization of cytoskeleton like as actin and regulation of transcription by ribosomal proteins or transcription factors. Unlike to negative charged silica nanoparticles, positive charged silica CL nanoparticle did not affect to sterol metabolism and lipid transport. Especially, some cell junction related genes (CTNNA1, PTPRM, CLDN19 and CTNNA1) were differentially expressed by positive charged silica nanoparticle, and these genes may be involved in interaction between the positive charged nanoparticle and molecules with negative charge present in cellular membrane. Thus, we suggest that specific surface charge of silica nanoparticle may be an important point being considered when assesses the safety of silica nanoparticles in neuronal cells.

Fabrication of Nearly Monodispersed Silica Nanoparticles by Using Poly(1-vinyl-2-pyrrolidinone) and Their Application to the Preparation of Nanocomposites

정유선,전미영,김창근 한국고분자학회 2009 Macromolecular Research Vol.17 No.1

To fabricate dental nanocomposites containing finely dispersed silica nanoparticles, nearly monodispersed silica nanoparticles smaller than 25 nm were synthesized without forming any aggregates via a modified solgel process. Since silica nanoparticles synthesized by the Stober method formed aggregates when the particle size is smaller than 25 nm, the synthetic method was modified by changing the reaction temperature and adding poly(1- vinyl-2-pyrrolidinone) (PVP) to the reaction mixture. The size of the formed silica nanoparticles was reduced by increasing the reaction temperature or adding PVP. Furthermore, the formation of aggregates with primary silica nanoparticles smaller than 25 nm was prevented by increasing the amount of PVP added to the reaction mixture. To enhance the dispersion of the silica particles in an organic matrix, the synthesized silica nanoparticles were treated with 3-methacryloxypropyltrimethoxysilane (γ-MPS). A dental nanocomposite containing finely dispersed silica nanoparticles could be produced by using the surface-treated silica nanoparticles.

고농도의 Silica Nanoparticle을 함유한 Silica/polymer 나노복합체: 실리카 표면 특성에 따른 수소이온 전도성 및 수팽윤도 변화

김주영 ( Ju Young Kim ),김승진 ( Seung Jin Kim ),나재식 ( Jae Sik Na ) 한국공업화학회 2010 공업화학 Vol.21 No.5

Solvent-casting 공정을 통해서 제조되는 전형적인 Proton Exchange Membrane (PEM)과는 달리, 일종의 Bulk-Molding Compounds (BMC) Process와 유사한 공정을 사용하여서 실리카 나노 입자들이 나노 크기로 분산된 PEM을 제조하였다. 즉, 반응성 분산제인 Urethane Acrylate Nonionomer (UAN)와 Styrene, Styrene Sulfonic Acid (NaSS), 실리카 나노입자를 Dimethyl Sulfoxide (DMSO) 단일 용매에 혼합시키고 라디칼 개시제 존재 하에서 Mold내에서 공중합을 수행하면, 표면 특성이 각기 다른 실리카 나노 입자들이 나노 크기로 분산된 Poly(urethane acrylate-styrene-styrene sulfonic acid) random copolymer Membrane 즉 일종의 실리카/고분자 Nanocomposite Membrane이 제조될 수 있었다. 실리카 나노 입자들의 Membrane에서의 분산성은 TEM을 이용하여서 확인할 수 있었다. 제조된 Membrane은 분산된 실리카 나노입자들의 표면 특성에 따라서 각기 다른 수팽윤도 및 수소이온전도도 변화 거동을 나타내었다. Membrane에 친수성 실리카 나노입자들이 분산된 경우에는, Membrane의 수팽윤도가 다소 증가되었지만 거의 일정한 수소 이온 전도도를 나타내었다. 그러나 Membrane의 메탄올 투과도는 상대적으로 크게 감소되었다. 반면에 Membrane에 분산된 소수성 실리카 나노입자들이 분산된 경우에는, 수팽윤도는 크게 감소되었지만 수소 이온전도도는 거의 변화하지 않았다. 즉 소수성 실리카 나노입자들은 소수성 도메인에 분산되어서 친수성 도메인이 팽윤되는 것을 억제시키지만 수소 이온전도성에는 영향을 미치지 않기 때문이다. 따라서 membrane의 수팽윤도와 수소이온전도성을 실리카 나노 입자들의 표면 특성을 이용하여서 자유로이 조절이 가능하다는 것을 알 수 있었다. 흥미로운 것은 실리카 나노 입자를 membrane에 분산시키는 것만으로도 수소 이온 전도성을 유지시키면서 수팽윤도를 현저하게 저하시킬 수 있다는 것이다. A new one-shot process was employed to fabricate proton exchange membranes (PEMs) over conventional solvent-casting process. Here, PEMs containing nano-dispersed silica nanoparticles were fabricated using one-shot process similar to the bulk-molding compounds (BMC). Different components such as reactive dispersant, urethane acrylate nonionmer (UAN), styrene, styrene sulfuric acid and silica nano particles were dissolved in a single solvent dimethyl sulfoxide (DMSO) followed by copolymerization within a mold in the presence of radical initiator. We have successfully studied the water-swelling and proton conductivity of obtained nanocomposite membranes which are strongly depended on the surface property of dispersed silica nano particles. In case of dispersion of hydrophilic silica nanoparticles, the nanocomposite membranes exhibited an increase in water-swelling and a decrease in methanol permeability with almost unchanged proton conductivity compared to neat polymeric membrane. The reverse observations were achieved for hydrophobic silica nanoparticles. Hence, hydrophilic and hydrophobic silica nanoparticles were effectively dispersed in hydrophilic and hydrophobic medium respectively. Hydrophobic silica nanoparticles dispersed in hydrophobic domains of PEMs largely suppressed swelling of hydrophilic domains by absorbing water without interrupting proton conduction occurred in hydrophilic membrane. Consequently, proton conductivity and water-swelling could be freely controlled by simply dispersing silica nanopartilces within the membrane.

Comparative study on transcriptional responses of human neuronal cells to silica nanoparticles with different stabilizers

김연정,강성규,양성익 한국바이오칩학회 2010 BioChip Journal Vol.4 No.4

There is growing concern about the safety of engineered nanoparticles, which are produced for various industrial applications. The potential applications of the nanoparticles are critically compromised due to the well documented toxicity and lack of understanding about the mechanisms involved in the intracellular responses. In this study, we investigated about the comprehensive set of biological responses by LUDOX® silica nanoparticles (commercial colloidal silica nanoparticles in aqueous phase) with two different types (similar size and charge but different stabilizers) in human neuronal cell line. The gene expression profiles were examined in SH-SY5Y cells exposed to LUDOX® silica AM and TM nanoparticles by using human whole genome oligonucleotide chip. Although the difference of cytotoxicity by silica AM and TM nanoparticles was not observed, transcriptional changes by these silica nanoparticles represented that silica TM affected to more many genes than silica AM. Several gene ontology (GO) categories of commonly changed genes by silica AM and TM nanoparticles include sterol metabolic process, lipid transport, ribosomal subunit, negative regulation of cellular component (including cytoskeleton) organization, and thyroglobulin type-1. In the case of silica TM nanoparticle data set, the changes of more various functions than it of silica AM were observed. Especially, functions related to cytoskeleton were annotated in both silica AM and TM nanoparticles. Therefore, it suggests that endocytosis of silica nanoparticles occurs by the reorganization of cell cytoskeleton through transcriptional changes of related genes. Thus, this study suggests that silica AM and TM nanoparticles affect on neuronal cell systems through a variety of interruption to biological processes. In the present study, we identified several silica AM and TM nanoparticles-responsive common genes. Further research is required to study the biological consequences of these differentially expressed genes (DEGs) and to verify usefulness of the potential biomarkers for risk assessment of silica nanoparticles.

Induction of Functional Changes of Dendritic Cells by Silica Nanoparticles

강경아,임종석 대한면역학회 2012 Immune Network Vol.12 No.3

Silica is one of the most abundant compounds found in nature. Immoderate exposure to crystalline silica has been linked to pulmonary disease and crystalline silica has been classified as a Group I carcinogen. Ultrafine (diameter <100nm) silica particles may have different toxicological properties compared to larger particles. We evaluated the effect of ultrafine silica nanoparticles on mouse bone marrow-derived dendritic cells (BMDC) and murine dendritic cell line, DC2.4. The exposure of dendritic cells (DCs) to ultrafine silica nanoparticles showed a decrease in cell viability and an induction of cell death in size- and concentration-dependent manners. In addition, in order to examine the phenotypic changes of DCs following co-culture with silica nanoparticles, we added each sized-silica nanoparticle along with GM-CSF and IL-4during and after DC differentiation. Expression of CD11c, a typical DC marker, and multiple surface molecules such as CD54, CD80, CD86, MHC class II, was changed by silica nanoparticles in a size-dependent manner. We also found that silica nanoparticles affect inflammatory response in DCs in vitro and in vivo. Finally, we found that p38 and NF-κB activation may be critical for the inflammatory response by silica nanoparticles. Our data demonstrate that ultrafine silica nanoparticles have cytotoxic effects on dendritic cells and immune modulation effects in vitro and in vivo.