• 공업화학
• /
• 제27권1호
• /
• pp.26-34
• /
• 2016

본 연구에서는 반응성 비닐기를 가지고 있는 반응성 양친성 고분자 전구체(Reactive Amphiphilic Reactive Polymer Precursor) (RARP)를 이용하여 제조된 소수성 세그먼트들이 가교된 코아 가교 양친성 고분자(Core-crosslinked Amphiphilic Polymer) (CCAP) 나노입자와 나노침전법을 사용하여서 소수성 유용물질을 고함량으로 담지할 수 있는 새로운 공정을 제안하였다. 극성이 각기 다른 유기용매(에탄올, 아세톤, 테트라하이드로퓨란(THF))들과 소수성 세그먼트 분자량이 다른 CCAP를 사용하여서, 모델 유용 약물인 ${\alpha}$-tocopherol의 담지 효율, 담지량 및 약물 담지 나노입자의 크기와 안정성 변화를 조사하였다. 소수성 세그먼트 분자량이 큰 CCAP와 소수성 용매인 THF를 용매로 사용한 경우에 가장 높은 유용 약물 담지량, 담지 효율을 나타내는 안정한 나노입자가 형성이 되었다. 즉 CCAP 나노입자들의 물리적 화학적으로 견고한 나노 구조로 인해서 33 wt%의 높은 담지량과 97% 이상의 담지 효율을 가지면서 물속에서 70 nm의 크기의 안정한 유용 약물 담지 고분자 나노입자를 제조할 수 있었다.

• 반도체디스플레이기술학회지
• /
• 제21권1호
• /
• pp.67-70
• /
• 2022

In order to prevent water vapor and oxygen permeation in the organic light emitting diodes (OLED), Al₂O₃ thin-film encapsulation (TFE) technology were investigated. Atomic layer deposition (ALD) method was used for making the Al₂O₃ TFE layer because it has superior barrier performance with advantages of excellent uniformity over large scales at relatively low deposition temperatures. In this study, the thickness of the Al₂O₃ layer was varied by controlling the numbers of the unit pulse cycle including Tri Methyl Aluminum(Al(CH₃)₃) injection, Ar purge, and H₂O injection. In this case, several process parameters such as injection pulse times, Ar flow rate, precursor temperature, and substrate temperatures were fixed for analysis of the effect only on the thickness of the Al₂O₃ layer. As results, at least the thickness of 39 nm was required in order to obtain the minimum WVTR of 9.04 mg/m²day per one Al₂O₃ layer and a good transmittance of 90.94 % at 550 nm wavelength.

• 한국약용작물학회지
• /
• 제17권4호
• /
• pp.257-265
• /
• 2009

Phosphatidylcholine was used to encapsulate aqueous extracts of Centella asiatica, and its biological activity was compared with another aqueous extracts. Nanoparticle of C. asiatica was made by encapsulation to w/o type spherical liposome which of aqueous extracts seized with oil phase as 78.2 nm average diameter. Cytotoxicity of the nanoparticle was measured on human skin fibroblast cells, CCD-986sk, and showed lower cytotoxicity on 1.0 mg/$m{\ell}$ of highest concentration as 28% than that of another extracts. The nanoparticle showed the highest promotion of human B and T cell growth up to 138% and 135%, respectively, compared to the control. and the NK cell growth was promoted up to 8% higher than the control in proportion to secretion of IL-6 and TNF-$\alpha$ from immune cell growth. Also nanoparticle showed highest inhibition activity of hyaluronidase on 1.0 mg/$m{\ell}$ of highest concentration as 60.5%. It seems that because of enhanced biological application of aqueous extracts on cell through nano-encapsulation process.

• Journal of Microbiology and Biotechnology
• /
• 제11권3호
• /
• pp.423-427
• /
• 2001

Chitosan/alginate capsules were formed by electrostatic interactions and had appropriated mechanical strength, permeability to albumin, and stability to hepatocytes. Rat hepatocytes were isolated and immobilized in chitosan/alginate capsules. During the encapsulation process with hepatocyte, 10% of viability was decreased mainly due to the low pH of the chitosan solution. Among various capsule fabrication methods, the chitosan-alginate capsule showed the highest mechanical strength. Addition of collagen in the capsule with hepatocytes enhanced hepatic metabolism as well as the cell viability for 2 weeks of culture. The hepatocyte in the capsule without collagen decreased the viability to 10% for 2-week cultures.

• Macromolecular Research
• /
• 제17권11호
• /
• pp.926-930
• /
• 2009

A new method for encapsulating nanomaterials within intermediary layer cross-linked (ILCL) polymeric micelles using a bifunctional photo-cross-linking agent was developed. For ILCL polymeric micelles, an amphiphilic triblock copolymer of poly(ethylene glycol)-b-poly(2-hydroxyethyl methacrylate)-b-poly(methyl methacrylate) (PEG-PHEMA-PMMA) was synthesized via consecutive atom transfer radical polymerization (ATRP), Di(4-hydroxyl benzophenone) dodecanedioate (BPD) was used as a bifunctional photo-cross-linking agent. The PMMA-tethered Au nanoparticles and BPD, or pyrene and BPD were encapsulated in the PEG-PHEMA-PMMA micelles, and their intermediary layers were photo-cross-linked by UV irradiation for 1 h. The HEMA units donated labile hydrogens to the excited-state benzophenone groups in BPD, and they were subsequently cross-linked by BPD through radical-radical combination. The spherical structures of the PEG-PHEMA-PMMA micelles containing the Au nanoparticles or pyrene were unaffected by the photo-cross-linking process.

• 유기물자원화
• /
• 제19권2호
• /
• pp.16-21
• /
• 2011

생물흡착제는 그 자체만으로 실제폐수처리에 적용하기에는 충분하지 못한 구조를 가지고 있기 때문에 고정화는 매우 중요하다. 그래서 최근의 연구는 생물흡착제를 효과적으로 고정화시키는 방법에 초점이 맞추어져 있다. 미생물이나 다당류와 같은 생물흡착제의 기계적 강도를 향상시키기 위하여 지금까지 많은 고정화 방법이 제안되어 왔다. 본 연구에서는 다양한 고정화 방법들(adsorption, covalent binding, entrapment, encapsulation, and crosslinking)을 소개하고자 한다.

• Korean Chemical Engineering Research
• /
• 제55권3호
• /
• pp.313-321
• /
• 2017

바이오 고분자인 알긴산 나트륨(Sodium Alginate)을 이용하여 기존의 방법에 비해 생산성이 우수한 캡슐화의 상업화 공정을 개발하고자 하였다. 또한, 동일 공정으로 키토산을 알긴산과 함께 캡슐화하여 알긴산 나트륨으로 캡슐화 된 유산균과 비교하였다. 유산균 캡슐화의 상업화 공정의 주요 공정은 캡슐화 후 기존의 동결건조 대신에 본 연구진이 개발한 생산성이 우수한 유동화 건조 방법에 의하여 건조시간을 15~24이상 단축할 수 있었지만, 생균수는 동결건조와 유동층 건조의 비율이 1:0.75로 동결건조 방법이 좋았다. 하지만 건조에 드는 비용과 시간을 고려 해 볼 때 유동층 건조 방법으로 상업화 공정이 가능함을 확인할 수 있었다. Chitosan-alginate 캡슐은 알긴산 칼슘캡슐과 생균수를 비교하였을 때, 알긴산을 이용한 캡슐은 희석배수 $10^{-9}$, 즉 약 $1{\times}10^9$ 마리 이상의 균이 존재하고, 키토산을 이용한 캡슐은 희석배수 $10^{-3}$, 즉 약 $1{\times}10^3$ 마리의 균이 존재함을 확인 할 수 있었다. 본 연구의 기술로 제조된 유산균 캡슐은 pH 4.65, 6.01에서 96시간 이상 동안 안정하였지만, pH 7.07, 8.35에서는 1시간 이내에 모두 붕해되었다. 이는 유산균 캡슐이 위산에서 안정성을 보이고 pH 7이상을 띠는 소화기관인 소장과 대장에서는 쉽게 붕해가 일어날 수 있음을 알 수 있었다.

• 대한화학회지
• /
• 제64권5호
• /
• pp.259-266
• /
• 2020

The main purpose of this study is to examine the different physicochemical properties of spray-dried products. The carrier agents and powders after the spray-drying process were analyzed for encapsulation yield, moisture content, color parameters, total polyphenol content (TPC), antioxidant capacity (AC), bulk density, flowability, wettability, hygroscopicity, water solubility index (WSI), particle size and microstructure. The spray-drying process was carried out with different carrier agents including maltodextrin (MD) and the combination of maltodextrin and gum arabic (MD-GA) with MA/GA ratio of 70/30, dried at the inlet/outlet air temperature of 160 ℃/70 ℃, 4 bar, airflow rate of 70 ㎥·h^-1 and feed flow rate of 750 mL·h^-1. The results showed that the different carrier agents have significant influences on the physicochemical properties of the powder produced by the spray-drying method. In there, while the values of recovery efficiency and flowability of spray-dried products from MD are higher than those of spray-dried products from MD-GA combination, the opposite is true for the values of TPC, AC, bulk density and wettability, whereas hygroscopicity and WSI values are equally represented in both products.

• 한국재료학회지
• /
• 제31권1호
• /
• pp.54-59
• /
• 2021

In this work, narrow-band green-emitting CsPbBr3 particles are embedded in commercialized glass composites by a facile dry process. By optimizing the method through sintering in glass frit (GF) composites including CsBr and PbBr2, used as precursors, the encapsulation of CsPbBr3 particles made them waterproof with green fluorescence. To improve the fluorescent properties by reducing aggregation of CsPbBr3, fumed silica (FS) is additionally used to help particles avoid bulking up in the glass matrix. The CsPbBr3 perovskite/glass composites are characterized using scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy (EDS) maps, which support the existence of CsPbBr3 particles in the glass matrix. The photoluminescence (PL) properties demonstrate that the emission spectrum peak, full width at half maximum (FWHM), and photoluminescence quantum yield (PLQY) values are 519 nm, 17 nm, and 17.7 %. We also confirm the water-resistant properties. To enhance water/moisture stability, the composite sample is put directly into water, with its PLQY monitored periodically under UV light.

• 정보화연구
• /
• 제10권3호
• /
• pp.295-303
• /
• 2013

This paper presents a new approach to managing dynamic business process changes based on business process change patterns. We identify and categorize business process change patterns that occur recurrently in a dynamic business environment. Several issues regarding management of process versions are discussed, and a pattern-based version management method for handling process changes more flexibly is explained in detail. We propose a mechanism for abstract process execution with runtime encapsulation of a business process, which can maximize the flexibility of process execution using multiple process versions. In addition, we propose a concept of process promotion and demotion that can dynamically choose an actual version of the process at run-time. With our pattern-based process change management and versioning approach, it is expected that the flexibility and efficiency of BPM systems can be enhanced significantly.