• 한국축산식품학회지
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• 제33권4호
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• pp.515-521
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• 2013

In this study, we examined the effects of organic types of calcium derived from oyster shell (OS-Ca) and nano-calcium (Nano-Ca) on the bio-availability and physiological responses associated with bone health in ovariectomised rats. Increased body weight, which is one of the physiological effects of ovary removal, was significantly recovered by Nano-Ca treatment (p<0.05). The reduced calcium level in the liver in ovariectomised rat was increased significantly with OS-Ca and Nano-Ca treatment (p<0.05), suggesting improved calcium bio-availability. Alkaline phosphatase (ALP), osteocalcin, and deoxypyridinoline (DPD) were analysed as biochemical markers of bone metabolism and health in the presence or absence of OSCa and Nano-Ca. ALP, osteocalcin, and DPD levels increased following ovary removal and tended to decrease after treatment with Nano-Ca, indicating that Nano-Ca induces favourable bone metabolism. This result was reflected in the recovery of bone mineral density (BMD) and bone mineral content (BMC) of the femur after Nano-Ca treatment following ovary removal. Taken together, our data show that the tested calcium treatments, especially using Nano-Ca, enhanced the bioavailability or absorption of calcium and positively affected bone metabolism in ovariectomised rats.

• 한국세라믹학회지
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• 제50권4호
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• pp.275-279
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• 2013

The purpose of this study was to prepare calcium phosphate cement [CPC] for use in artificial bone. Nano-crystalline calcium phosphate [CaP] was precipitated at $37^{\circ}C$ using highly active $Ca(OH)_2$ in DI water and an aqueous solution of $H_3PO_4$. From the XRD measurements, the nano-CaP powder was close to apatitic TCP phase and the powders fired at $800^{\circ}C$ showed a critical ${\beta}$-TCP phase. A mixture of one mole $CaCO_3$ and two moles di-calcium phosphate was calcined at $1100^{\circ}C$ to make a reference ${\beta}$-TCP material. The nano-CaP powders were added to the normal ${\beta}$-TCP matrix and fired at $900^{\circ}C$ to make a ${\beta}$-TCP block. The sintered block showed improved mechanical strength, which was caused by the solid state interaction between nano-CaP and normal ${\beta}$-TCP.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.145-146
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• 2020

This study investigated the performance evaluation of polymer cement mortar for repairing concrete structures using calcium nitrite(Ca(NO₂)₂) and CO₂ nano-bubble mixing water to develop section-restoration methods for the repair and reinforcement of cracks. The evaluation items were strength and microstructure analysis at 28 days of age according to the change in the amount of calcium nitrite and the use of CO₂ nano-bubble water. As a result of the experiment, it was confirmed that the performance of polymer cement mortar for repairing concrete structures was improved by the generation of nitrite-based hydration products when calcium nitrite and CO₂ nano-bubble water were used.

• 한국식품영양과학회지
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• 제44권1호
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• pp.29-34
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• 2015

본 연구에서는 난각 칼슘을 이용하여 분획 공정을 통해 나노칼슘을 제조(입자 크기가 96.5 nm)하였으며 이에 대해 안전성 평가를 위해 OECD guideline에 따라 동물을 이용하여 단회투여의 급성 독성시험과 반복투여의 아급성 독성시험을 실시하였다. 그 결과 급성 및 아급성 독성시험의 모든 암수동물에서 나노 칼슘의 투여에 기인된 사망은 관찰되지 않았으며 나노 칼슘은 모든 암수 rat에 대하여 대조군과 비교하여 유의성 있는 체중 변화를 초래하지 않았다. 또한 나노 칼슘 투여군에서 특이한 임상 증상 및 부검 시 내부 장기의 어떠한 육안적 이상소견도 관찰되지 않았다. 따라서 급성 및 아급성 독성시험의 결과 나노 칼슘은 혈액과 장기 등 평가 지표에 독성으로 인한 영향을 나타내지 않으며 안전한 것으로 판단되었다.

• 한국건설순환자원학회논문집
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• 제2권4호
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• pp.297-306
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• 2014

Recently nano-materials are gaining more importance in the construction industry due to its enhanced energy efficiency, durability, economy, and sustainability. Nano-silica addition to cement based materials can control the degradation of the fundamental calcium-silicate-hydrate reaction of concrete caused by calcium leaching in water as well as block water penetration and therefore lead to improvements in durability. In this paper, the influence of synthesized nano silica from locally available rice husk on the mechanical properties and corrosion resistant properties of OPC (Ordinary Portland Cement) has been studied by conducting various experimental investigations. Micro structural properties have been assessed by conducting Scanning Electron Microscopy, Thermo gravimetry and Differential Thermal Analysis, X-Ray Diffraction analysis, and FTIR studies. The experimental results revealed that NS reacted with calcium hydroxide crystals in the cement paste and produces Calcium Silicate Hydrate gel which enhanced the strength and acts as a filler which filled the nano pores present in concrete. Hence the strength and corrosion resistant properties were enhanced than the control.

• 한국세라믹학회지
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• 제53권2호
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• pp.222-226
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• 2016

The synthesis of pure calcium carbonate nanocrystals was achieved using a simultaneous injection method to produce nano particles of uniform size. These were characterized using scanning electron microscopy and powder X-ray diffraction. The nano particles were needle-shaped aragonite polymorphs, approximately 100-200 nm in length. The aragonite polymorph of calcium carbonate was prepared using aqueous solutions of $CaCl_2$ and $Na_2CO_3$, which were injected simultaneously into double distilled water at $50^{\circ}C$ and then allowed to react for 1.5 h. The resulting whisker-type nano aragonite with high aspect ratio (30) is biocompatible and potentially suitable for applications in light weight plastics, as well as in the medical, pharmaceutical, cosmetic and paint industries.

• 펄프종이기술
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• 제46권4호
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• pp.1-10
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• 2014

In papermaking industry, inorganic fillers are widely used for the purpose of improving opacity, brightness, printability, uniformity and dimensional stability. They are also useful for production costs and energy savings. In the past, inorganic fillers in papermaking industry only focused on micro-scale but recently, new trials on nano-powdered technology are applying. Even nano-powdered fillers are rapidly utilized for improving the optical and surface properties in coating and surface sizing, there still have some problems in wet-end process due to poor dispersibility and retention. In this study, nano-particled calcium carbonate was produced by milling the PCC and its applicability between micro sized and nano sized calcium carbonated was compared in wet-end process, and finally the sheet properties were evaluated. Nano-PCC was not retained in sheet structure without applying retention system, but with retention system nano-powdered PCC was absorbed on fiber surface with expanding the fiber networks. The application of PAM-bentonite system has resulted in high ash retention and bulky structure for copier paper, and good optical properties in brightness and opacity. However, it required to solve the weakness of low tensile property due to interruption of hydrogen bonding by nano fillers.

• 대한금속재료학회지
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• 제46권2호
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• pp.105-110
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• 2008

Process of the hydroxyapatite (HA) formation on bioactive titanium metal prepared by NaOH treatment in a modified-simulated body fluid (mSBF) containing bovine serum albumin (BSA) was investigated by high resolution transmission electron microscope attached with energy dispersive X-ray spectrometer (EDX). The amorphous titanate, which was formed on titanium surface by NaOH treatment, combined with the calcium ions in the liquid to form an amorphous calcium titanite. With increasing of soaking time in the liquid, an amorphous calcium titanite combined with the phosphate ions to form an amorphous calcium phosphate with low Ca/P atomic ratio, and it grows as aggregates of plate (or needle)-like substance on titanium surface. The crystalline apatite layers, which are needle-shaped with the c axis parallel to the long axis, are formed in an amorphous calcium phosphate with further increase in soaking time. The formation of needle-shaped apatite layers can be explained by electrostatic effects and difference of concentration between calcium, phosphate, and albumin ions.

• 한국세라믹학회지
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• 제53권6호
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• pp.670-675
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• 2016

Calcium phosphate crystallites were prepared by wet chemical method for use in artificial bone. In order to obtain ${\beta}$-tricalcium phosphate (TCP), nano-crystalline calcium phosphate (CaP) was precipitated at $37^{\circ}C$ and at $pH5.0{\pm}0.1$ under stirring using highly active $Ca(OH)_2$ in DI water and an aqueous solution of $H_3PO_4$. The precipitated nano-crystalline CaP solution was kept at $90^{\circ}C$ for the growth of CaP crystallites. Through the growing process of CaP crystallites, we were able to obtain various sizes of rectangular CaP crystallites according to the crystal growing times. Dry nano-crystalline CaP powders at $37^{\circ}C$ were mixed with dry macro-crystalline CaP crystallites and the shaped mixture sample was fired at $1150^{\circ}C$ to make a ${\beta}-TCP$ block. Several tens of nm powders were uniformly coated on the surface, which was comprised of powders of several tens of ${\mu}m$, using a vibrator. The mixing ratio between the nanometer powders and the micrometer powders greatly affected the mechanical strength of the mixture block; the most appropriate ratio of these two materials was 50 wt% to 50 wt%. The sintered block showed improved mechanical strength, which was caused by the solid state interaction between the nano-crystalline ${\beta}-TCP$ and the macro-crystalline ${\beta}-TCP$.

• 생명과학회지
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• 제29권7호
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• pp.769-773
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• 2019

본 연구에서는 습식 나노화 공정 기술을 적용하여 제조한 식물영양제를 이용하여 사과 잎에 흡수되는 칼슘과 마그네슘의 이동 경로 및 흡수율을 비교 분석하였다. 습식 나노화 공정을 통해 불용성 칼슘과 마그네슘을 나노화 처리한 식물영양제의 성분 함량 및 이동경로를 확인하기 위하여 식물 영양제 살포 후 2주, 4주 및 8주 경과 후 잎자루, 잎몸, 옆면으로 구분하여 SEM, EDS 촬영을 통해 분석하였다. 잎자루는 식물 영양제 살포 후 4주차부터 증가하여 8주차에서는 1,115%까지 증가했으며, 사과 잎몸의 경우 2주차의 미살포구에 비해 살포 후 칼슘과 마그네슘의 함량이 감소하였으나, 4주 이후부터는 증가하였으며, 4주차의 뒷면 증가율이 539%로 가장 높았다. 또한, 잎몸의 옆면은 미살포구에 비해 살포구 모두 칼슘과 마그네슘 함량이 증가하였는데 특히, 4주차에 673% 증가하여 가장 높은 증가율을 보였다. 시간이 경과함에 따라 모든 살포구가 미살포구에 비해 칼슘, 마그네슘 함량이 점점 증가하여 나노화 식물영양제의 불용성 칼슘과 마그네슘 성분이 사과의 잎자루에서 잎몸까지 이동한 것으로 판단된다. 본 연구 결과를 보았을 때 습식 나노 공정 기술을 통해 제조된 식물영양제를 활용하면 사과 이외의 다른 작물 에서도 칼슘과 마그네슘 흡수 효과를 얻을 수 있을 것으로 판단하였다. 또한, 식물영양제 이외에도 천연물이나 바이오산업에도 나노 공정 기술의 적용이 가능할 것으로 기대된다.