Fe3O4/SiO2/YVO4:Eu3+ multifunctional nanoparticles are successfully synthesized by facile stepwise sol-gel processes. The multifunctional nanoparticles show a spherical shape with narrow size distribution (approximately 40 nm) and the phosphor shells are well crystallized. The Eu3+ shows strong photoluminescence (red emission at 619 nm, absorbance at 290 nm) due to an effective energy transfer from the vanadate group to Eu. Core-shell structured multifunctional nanoparticles have superparamagnetic properties at 300 K. Furthermore, the core-shell nanoparticles have a quick response time for the external magnetic field. These results suggest that the photoluminescence and magnetic properties could be easily tuned by either varying the number of coating processes or changing the phosphor elements. The nanoparticles may have potential applications for appropriate fields such as laser systems, optical amplifiers, security systems, and drug delivery materials.

올레핀/파라핀 분리를 위해 silver nanoparticle을 운반체로 이용하는 촉진수송막이 최근 많은 관심을 받고 있다. 기존 연구에서는 silver nanoparticle의 전구체로서 AgBF4가 사용되어 왔다. 하지만 상대적으로 고가에 속하는 AgBF4는 상업화에 적합하지 않기 때문에 비교적 저렴한 AgClO4를 전구체로 이용해 제조된 silver nanopaticle를 활용해서 PEBAX-5513/AgNPs (전구체: AgClO4)/7,7,8,8-tetracyanoquinodimethane (TCNQ) 복합막이 제조되었다. 그러나 여러 조성의 복합막이 제조되었으 나 올레핀 분리성능은 관찰되지 않았다. FT-IR 분석 결과는 PEBAX-5513 고분자 내에서 silver nanoparticle이 형성되고 TCNQ에 의해 표면이 양극성화 되는 것을 확인하였지만 형성된 silver nanoparticle이 안정화 되지 못한 것으로 분석되었다. 이러한 결과들을 통해 은염 전구체의 음이온이 올레핀/파라핀 분리막에서 중요한 역할을 하는 것으로 판단되었다.

In the present study, rutile phase titanium dioxide nanoparticles (R-TiO2 NPs) were prepared by hydrolysis of titanium tetrachloride in an aqueous solution followed by calcination at 900℃. The composition of R-TiO2 NPs was determined by the analysis of X-ray diffraction data, and the characteristic features of R-TiO2 NPs such as the surface functional group, particle size, shape, surface topography, and morphological behavior were analyzed by Fourier-transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, transmission electron microscopy, dynamic light scattering, and zeta potential measurements. The average size of the prepared R-TiO2 NPs was 76 nm, the surface area was 19 m2/g, zeta potential was −20.8 mV, and average hydrodynamic diameter in dimethyl sulfoxide (DMSO)–H2O solution was 550 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphological observations revealed that R-TiO2 NPs were cytocompatible with oral cancer cells, with no inhibition of cell growth and proliferation. This suggests the efficacy of R-TiO2 NPs for the aesthetic white pigmentation of teeth.

본 리뷰 논문은 식품 산업에서 나노 기술의 활용에 관한 보고이다. 식품 병원균에 대한 항균 활성을 갖는 생리 활성 성분은 식품 보존시 효율성을 향상시키고 보존성을 증진시키기 위해 나노입자(NPs)로 캡슐화된다. 그러나, 이러한 NPs는 인간에게 생체 적합성과 무독성을 지녀야 된다. 식품 보존분야의 발전은 일부 산업 분야에서 식품 포장용 NPs의 개발을 가져왔다. 식품 산업 분야에서 가장 일반적으로 사용되는 NPs 그룹은 금속 산화물이다. 산화 아연과 이산화 티타늄 같은 금속 산화물 NPs는 식품 재료에 서 항균 활성을 나타내기 때문에, NPs는 강화된 기능적 특성으로 식품 보존에 사용될 수 있다. 식품 영양과 관능적 특성과 관련된 나노 기술의 적용은 나노 기반 식품 제조 및 보존에 관한 안전규제를 중심으로 간략하게 정리하였다.

Comparisons between bare carbon (CPs) and nitrogen-doped carbon nanoparticles (N-CPs) synthesised using hydrothermal reaction are carried out. It was found that hydrothermal reaction of citric acid yields graphene-like sheets, while the nitrogen doping using ethylenediamine resulted in amorphous polymeric ball-like hydrocarbons devoid of any aromatic rings. Although the Fourier transform infrared spectroscopy, Raman spectroscopy and nuclear magnetic resonance spectroscopy indicate the presence of carbon–carbon double bonds (C=C), and the ground states of both materials are very deep (> 7.8 eV) as measured by ultraviolet photoelectron spectroscopy. This indicates the conjugation is very short. This is supported by the fact that both materials are UV blue emitting peaking at 375 nm probably originating from C=C.

In this study, ultrasonic spray pyrolysis combined with salt-assisted decomposition, a process that adds sodium nitrate (NaNO3) into a titanium precursor solution, is used to synthesize nanosized titanium dioxide (TiO2) particles. The added NaNO3 prevents the agglomeration of the primary nanoparticles in the pyrolysis process. The nanoparticles are obtained after a washing process, removing NaNO3 and NaF from the secondary particles, which consist of the salts and TiO2 nanoparticles. The effects of pyrolysis temperature on the size, crystallographic characteristics, and bandgap energy of the synthesized nanoparticles are systematically investigated. The synthesized TiO2 nanoparticles have a size of approximately 2–10 nm a bandgap energy of 3.1–3.25 eV, depending on the synthetic temperature. These differences in properties affect the photocatalytic activities of the synthesized TiO2 nanoparticles.

양친성 PCZ-r-PEG 랜덤 공중합체를 기반으로 한 수열합성법을 통해 자가조립된 메조기공 이산화티타늄 마이크로 스피어를 합성하였다. 중합된 PCZ-r-PEG는 푸리에 변환 적외분광법(fourier transform infrared spectroscopy, FT-IR), 핵자기 공명(nuclear magnetic resonance, NMR), 젤 투과 크로마토그래피(gel permeation chromatography, GPC) 그리고 투과전자 현미경(transmission electron microscopy, TEM)을 통해 그 특성이 분석되었다. 다공성 이산화티타늄 입자는 PCZ-r-PEG, 글루코스(glucose), 물을 테트라히드로푸란(tetrahydrofuran, THF) 용액에 분산시킨 뒤 150°C, 12시간 동안 반응시켰다. 다공성 이산화티타늄 입자의 구조와 결정성 분석을 위해 주사전자현미경(scanning electron microscopy, SEM)과 엑스선 회절(X-ray diffraction, XRD)이 사용되었다.

In this article, a new type of mesoporous carbon nanoparticles (MCN) was fabricated as a potential oral delivery system of insulin to reduce the adverse reactions by hypodermic injection. The mesoporous carbon nanoparticles-carried insulin (MCNI) was studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR) compared with the blank MCNs. The Brunauer–Emmett–Teller (BET) method was utilized to calculate the specific surface area. The pore volume and pore size distribution (PSD) curves were calculated by Barrett–Joyner–Halenda (BJH) model. The entrapment efficiency (EE%) and loading content (LC%) of insulin onto the MCNs were determined by RP-HPLC. In vitro insulin release from MCNI was determined in simulated intestinal fluid. To evaluate the pharmacodynamics of MCNIs orally, the variation of glycemia of diabetic rats after oral administration of MCNIs was compared with the rats receiving hypodermic injection of insulin. Besides, the absorption of FITC-labeled MCNs in HCT-116 cells was tested. The results showed that there is significant difference between MCNs and MCNIs through SEM, TEM, and FT-IR. The entrapment efficiency, loading content and in vitro insulin release met the requirements of the pharmacodynamic study. The specific surface area, pore volume and pore size of MCNIs were significantly decreased compared to that of MCNs. The pharmacodynamics study showed that the blood sugar level was significantly decreased after the oral administration of MCNIs. The FITC-labeled MCNs showed significant absorption in HCT-116 cells. The MCNIs were successfully synthesized with commendable entrapment efficiency and loading content which preferably decreased the blood sugar in diabetes rats via oral administration.

Piezoelectric energy harvesting technology is attracting attention, as it can be used to convert more accessible mechanical energy resources to periodic electricity. Recent developments in the field of piezoelectric energy harvesters (PEHs) are associated with nanocomposites made from inorganic piezoelectric nanomaterials and organic elastomers. Here, we used the BaTiO3 nanoparticles and piezoelectric poly(vinylidene fluoride) (PVDF) polymeric matrix to fabricate the nanocomposites-based PEH to improve the output performance of PEHs. The piezoelectric nanocomposite is produced by dispersing the inorganic piezo-ceramic nanoparticles inside an organic piezo-polymer and subsequently spin-coat it onto a metal plate. The fabricated organic-inorganic piezoelectric nanocomposite-based PEH harvested the output voltage of ~1.5 V and current signals of ~90 nA under repeated mechanical pushings: these values are compared to those of energy devices made from non-piezoelectric polydimethylsiloxane (PDMS) elastomers and supported by a multiphysics simulation software.

We have studied a method to prepare polydopamine-modified reduced graphene oxide-supported Pt nanoparticles (Pt– PDA–RGO). The Pt–PDA–RGO nanocomposites were synthesized by a wet-coating process, which was induced by selfpolymerization of dopamine. As an eco-friendly and versatile adhesive source in nature, dopamine could be easily adhered to surfaces of organic material and inorganic material via polymerization processes and spontaneous adsorption under weak alkaline pH conditions. To apply the unique features of dopamine, we synthesized Pt–PDA–RGO nanocomposites with a different quantity of dopamine, which are expected to preserve the improved Pt adsorption on graphene, resulting in the enhanced electrocatalytic performance. The morphology and micro-structure were examined by field emission scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Compared to pristine Pt–deposited RGO (Pt–RGO), Pt–PDA–RGO (30 wt% dopamine against RGO) nanocomposites showed a superior electrochemical active surface area for a methanol oxidation. This could be related to the fact that the optimized c

분리막 소재의 투과도와 선택도 사이의 trade-off 관계로 인해 여전히 많은 연구가 필요하다. 특히 고분자 분리막에 무기물 나노입자가 들어가 있을 때, 기체투과 거동의 학문적 이해는 여전히 부족하다. 따라서 본 연구에서는 분리막 소재로 가장 많이 사용되는 PDMS에 2~5 nm의 기공을 가지고 있으며 직경이 약 5 nm 크기의 aluminosilicate hollow nanoparticles 인 allophane을 이용하여 복합매질 분리막을 제조하여 기체투과특성을 연구하였다. 대표적인 분리막 소재인 PDMS에 친수성 allophane, 그리고 나노입자에 undecylenic acid로 표면을 개질한 allophane을 막 내부에 고르게 분산시켜 함량 별로 복합매질 분리막을 제조하였다. 나노입자가 분산된 혼합매질 분리막 내에서 기체의 투과 특성을 파악하고, 이에 따른 기체투과 거동과 나노입자가 가지고 있는 기공의 역할을 평가하고자 하였다. 표면개질된 allophane을 첨가함에 따라 기체 투과도와 산소/질소 그리고 이산화탄소/메탄의 선택도가 동시에 점진적으로 향상되는 결과를 얻었다.