Nano-Ag complexes prepared by γ-radiolysis and their structures and physical properties

Kim, Hwa-Jung,Choi, Seong-Ho,Park, Hae-Jun Elsevier 2012 Radiation physics and chemistry Vol.81 No.10

<P><B>Abstract</B></P><P>In this study, nano-silver (nano-Ag) complexes showing different properties have been synthesized as follows. Polypyrrolidone (PVP)-stabilized silver colloids (NAg), nano-Ag bound to silica (SiO<SUB>2</SUB>) (NSS), and nano-Ag bound to a complex of SiO<SUB>2</SUB> and polyaniline (PANI) (NSSPAI) were prepared via γ-irradiation at room temperature. NAg and NSS used PVP as a colloidal stabilizer, while NSSPAI did not use PVP as a colloidal stabilizer. Interesting bonding properties occurred in the nano-Ag complex and anticipated structural changes were clearly shown through a surface analysis of x-ray photoelectron spectroscopy (XPS). The morphologies by field emission-scanning electron microscopy (FE-SEM) analysis showed that nano-Ag complexes have various particle sizes ranging from 10 to 30nm. NSS (average, 10nm) and NSSPAI (average, 30nm) showed a uniformly spherical shape and size, while NAg did not. From the reflection peaks in the x-ray diffraction (XRD) patterns, surface crystallinity of the nano-Ag complexes was indicated to be in the same degree as that of NSSPAI>NSS>NAg. Also, in the contact angle (CA) determination, surface hydrophobicity of NSSPAI was stronger than those of NSS and NAg, relatively. The different nano-Ag complexes prepared by γ-irradiation can be applicable in various industry fields due to the increase in specific property.</P> <P><B>Highlights</B></P><P>► Nano-Ag complexes showing different properties have been synthesized via γ-irradiation. ► Nano-Ag colloid (NAg), nano-Ag bound to SiO<SUB>2</SUB> (NSS), nano-Ag bound to SiO<SUB>2</SUB> and PANI complex (NSSPAI). ► Nano-Ag complexes were the same based on Ag metal. ► Results clearly showed fascinating/different physical properties. ► Different nano-Ag complexes can be applicable in various industry fields.</P>

Analysis of Mechanical Properties and Microstructure of Nano- and Micro-SiO2 Materials as Cementitious Composite Binder

김원우,문재흠 한국콘크리트학회 2024 International Journal of Concrete Structures and M Vol.18 No.1

This study evaluated the setting time, mechanical properties and microstructure of Portland cement (OPC) by adding SiO2 nano- and micro-particles. The setting time was reduced due to the pozzolanic reaction of the nano- and micro-SiO2, and the compressive strength was increased through a reduction in the porosity of the microstructure. When nano- and micro-SiO2 were used alone, micro-silica was the most effective in reduced the initial and final setting times and developing compressive strength. When two or more nano- and micro-SiO2 were used, a micro-sized binder and a small amount of nano-silica effectively improved performance as the setting time was reduced to 50–52% of that of ordinary Portland cement (OPC). It appears that a small amount of nano-silica could reduce the setting time and increase compressive strength because it caused the pozzolanic reaction and because the nanoparticles filled the pores between the silica fume and cement, which were composed of relatively large particles. This result could also be derived from compressive strength and microstructure analysis. Cement paste containing to nano- and micro-silica increased the strength by approximately 112% compared to OPC. Because nano-binders may cause a reduction in flow due to their large specific surface area, adding chemical admixture needs to be considered during mix design. In addition, the particle size distribution must be considered when nano- and micro-materials are used because an imbalance in particle size distribution can increase the pore size in the microstructure.

나노클레이 첨가량에 따른 나노재료 시멘트 모르타르에 정착된 보강섬유의 인발성능

오리온,박찬기,Oh, Ri-On,Park, Chan Gi 한국농공학회 2013 한국농공학회논문집 Vol.55 No.3

Recently, it has been studied for the application of nano-materials in the concrete. Applied a small amount of nano-materials can achieve the goal of high strength, high performance and high durability. The small addition of nano clay improves strength, thermal stability, and durability of concrete because of the excellent dispersion. The present study has investigated the effectiveness, when varying with the contents of nano clay, influencing the pull-out behavior of macro synthetic fibers in nano materials cement mortar. Pullout tests conducted in accordance with the Japan Concrete Institute (JCI) SF-8 standard for fiber-reinforced concrete test methods were used to evaluate the pullout performance of the different nano clay. Nano clay was added to the 0, 1, 2, 3, 4 and 5 % of cement weight. The experimental results demonstrated that the addition of nano clay led to improve the pull-out properties as of the load-displacement curve in the precracked and debonded zone. Also, the compressive strength, flexural strength and pullout performance and of Mix No. 1 and No. 2 increased up to the point when nano clay used increased by 2 and 3 % contents, respectively, but decreased when the exceeded 3 and 4 %, respectively. It was proved by verifying increase of the scratching phenomenon in macro synthetic fiber surface through the microstructure analysis on the surface of macro synthetic fiber.

Charging Effect of a Nano-Floating Gate Capacitor with Double-Layered Au Nano-Particles

김은규,이동욱,Min Seung Lee,이태희,김원목 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3

A nano-floating gate capacitor with double-layered Au nano-particles embedded in a SiO1:3N layer was fabricated and characterized. The Au nano-particles were formed from Au thin film with a nominal thickness of 1 nm and their average size and density were about 4 nm and 2 × 1012 cm-2, respectively. After the post-annealing process at 800 ℃ for 10 s, the flat-band voltage shift of the nano-floating gate capacitor with double-layered Au nano-particles was about 9 V when the applied gate voltage was swept from -10 V to +10 V. Signicantly, the flat-band voltage shifts were improved after the post-annealing process. The double-layered Au nano-particles embedded in a SiO1:3N dielectric showed feasibility as nano-floating gate capacitors for nonvolatile memories. A nano-floating gate capacitor with double-layered Au nano-particles embedded in a SiO1:3N layer was fabricated and characterized. The Au nano-particles were formed from Au thin film with a nominal thickness of 1 nm and their average size and density were about 4 nm and 2 × 1012 cm-2, respectively. After the post-annealing process at 800 ℃ for 10 s, the flat-band voltage shift of the nano-floating gate capacitor with double-layered Au nano-particles was about 9 V when the applied gate voltage was swept from -10 V to +10 V. Signicantly, the flat-band voltage shifts were improved after the post-annealing process. The double-layered Au nano-particles embedded in a SiO1:3N dielectric showed feasibility as nano-floating gate capacitors for nonvolatile memories.

<i>In-vivo</i> tumor targeting of pluronic-based nano-carriers

Kim, Ja-Young,Choi, Won Il,Kim, Young Ha,Tae, Giyoong,Lee, Seung-Young,Kim, Kwangmeyung,Kwon, Ick Chan Elsevier 2010 Journal of controlled release Vol.147 No.1

<P><B>Abstract</B></P><P>Pluronic-based nano-carriers including bare forms that were composed of Pluronic F 68(NC(PF 68)) or Pluronic F 127(NC(PF 127)), and chitosan-conjugated forms (Chito-NC(PF 68) or Chito-NC(PF 127)) were prepared by photo-polymerizing two kinds of diacrylated Pluronic (F 68 and F 127) and acrylated chitosan to investigate the effect of chitosan conjugation and their physicochemical characteristics (size and hydrophilicity) of Pluronic-based nano-carriers on the tumor targeting efficiency. All of the nano-carriers were stable in serum-containing media without forming any aggregation and did not show any acute cytotoxicity to both normal (NIH3T3 fibroblast) and tumor (SCC7) cells. Chitosan conjugation did not change their sizes or thermo-sensitive properties of the nano-carriers, but significantly increased their <I>in-vitro</I> cellular uptake compared to the corresponding bare forms. The <I>in-vivo</I> tumor accumulation of these nano-carriers was optically monitored by using Cy5.5-attached nano-carriers in SCC7 tumor-bearing mice. For all cases, local accumulation of the injected nano-carriers in liver was not dominant compared to the tumor site, demonstrating good tumor targeting efficacy of the Pluronic-based nano-carriers. Among different samples, chitosan-conjugated nano-carriers showed much better tumor accumulation than bare forms, and mostly remained up to 72h, implying prolonged blood circulation and more efficient tumor accumulation. Between Chito-NC(PF 68) and Chito-NC(PF 127), Chito-NC(PF 68) showed a little better tumor accumulation and retention, suggesting the difference in Pluronic, thus difference in hydrophilicity and the size of the nano-carriers also might affect the tumor targeting. In contrast, bare nano-carriers were initially accumulated well in tumor, but they were excreted from the tumor site relatively rapidly. Therefore, chitosan-functionalization was very effective for improving the tumor targeting efficacy of Pluronic-based nano-carriers.</P> <P><B>Graphical abstract</B></P><P>Chitosan-conjugated, Pluronic-based nano-carriers were very effective for tumor targeting and prolonged circulation <I>in vivo</I>.<ce:figure></ce:figure></P>

미래 의료용 나노로봇기술이 가져올 수 있는 해악 및 그 방지를 위한 입법적 개선방안 제언 ― 표적치료제 나노로봇을 중심으로 ―

정천교 ( Jeong Chun Gyo ) 연세대학교 법학연구원 의료·과학기술과 법센터 2018 연세 의료·과학기술과 법 Vol.9 No.1

수술은 인간의 생명과 직결되는 작용이다. 인간은 수술로 인한 해악방지 및 수술 효과의 극대화를 위해 끊임없이 연구해왔다. 현대 의공학 및 로봇기술의 발전에 따라 의료용 수술로봇의 활용이 그 대안으로서 떠올랐으며, 우리나라 또한 로봇기술 강국으로서 의료용 수술로봇에 대한 연구에 관하여 전 세계를 주도하고 있다. 의료용 수술로봇 가운데 현재 활발한 연구와 함께 발전하는 분야가 바로 나노로봇 분야이다. 그러나 기술의 발전과 함께 조심하여야할 점은 기술의 위험 증대 등이 일으킬 수 있는 생명윤리적 문제들이다. 특히 법을 다루는 법률가는 새로운 기술의 도입에 있어서 그 오남용을 방지하기 위한 규제 방안을 선제시하는 입법론적 논의를 이끌어야하며, 이는 법률가의 사회적 사명이다. 따라서 이와 같은 문제의식을 바탕으로 의료용 나노로봇의 예상되는 생명윤리적 해악들을 방지하기 위한 입법적 해결방안에 대하여, 법해석학적 및 비교법적 고찰 방법을 통해 그 방향성을 제시하여, 의사 뿐 아니라 환자들 모두의 이익을 증진시키기 위한 방안을 제시하고자 하였다. 본 연구에서는 논의를 펼칠 대상인 의료용 나노로봇에 관하여, 특정 질병을 치료하기 위하여 그 질병과 관련된 세포가 존재하는 체내 장소에 의약을 운반하는 역할을 하는 나노로봇에 한정하였다. 이러한 의료용나노로봇은 ①수술로봇으로서의 성질도 존재하나 동시에 ②그 자체로서 약물의 기능을 한다는 성질도 존재한다. 의료용 나노로봇수술이 가져올 수 있는 해악으로는 먼저 나노입자의 위험성을 들 수 있다. 이는 해악금지의 원칙과 사전예방금지의 원칙의 관점에서 바라볼 수 있다. 나노입자 자체의 독성 및 나노 입자의 인체내 축적 가능성을 고려할 때, 의료용 나노로봇 자체의 위험성은 나노입자의 특성상 불가피한 것이며, 아직까지 밝혀지지 않은 작용에 의한 위험성 또한 내포하고 있다. 따라서 위와 같은 예상되는 해악들에 관하여, 해악을 최소화 할 수 있는 명확한 기준 및 규제 방식의 설정이 필요한 바이다. 두 번째로는 나노로봇수술의 임상시험과 관련된 생명윤리적 문제를 검토하였다. 의료용 나노로봇은 새로운 수술방법임과 동시에 신약으로서의 성질도 지님으로써 필연적으로 임상시험 절차를 거쳐야 하며, 그에 따라 ① 충분한 정보에 의한 동의 문제, ② 취약한 연구대상자의 보호문제, ③ 임상시험의 절차적 문제 등의 생명윤리적 문제들이 파생되어 발생한다. 위와 같은 임상시험과 관련된 생명윤리적 문제를 해결하여야만, 환자의 자율성이 확보된 임상시험이 가능하며, 그에 따라 환자의 건강을 직접적으로 보호할 수 있을 것이다. 세 번째로는 분배의 정의에 관하여 검토해보았다. 수술 및 치료에 관한 연구는 그 자체로서 인간의 생명과 건강이라는 근원 가치와 직결되어 있기에 분배의 정의가 반드시 실현되어야 한다. 의료용 나노로봇기술과 같은 고도화된 기술은 경제적 차이에 의한 불평등을 야기할 수 있는 것이지만, 나노로봇기술의 발전과 보편화를 통하여 개발도상국 등 전 세계에서의 서비스 이용가능성을 실현한다면 오히려 분배의 정의를 실현할 수는 지름길이 될 수 있다고 본다. 이를 위하여 선제적으로 나노로봇기술과 같은 의료서비스의 분배적 정의를 실현하기 위한 선언 및 제도 구축 등이 필요하다. 이러한 해악들을 방지하기 위한 입법적 개선방안을 제시하기 위하여, 현재 우리나라의 입법 상황을 검토해보았다. 검토 결과 의료용 나노로봇을 명확히 규율하는 개별 법률이 보이지 않으며, 「의료기기법」과 「약사법」에서 그 규율의 여지가 보이나, 이 또한 명확치 않은 실정이다. 필자는 의료용 나노로봇이 단순한 약물이 아닌 일정한 기능을 하는 로봇임을 전제한 후, 의료용 나노로봇을 의료기기로 보아 「의료기기법」상의 규율 대상에 포함하는 것이 타당하다고 보았다. 뿐만 아니라 의료용 로봇으로서의 규율, 그리고 나노물질로서의 규율을 더하여, 의료용 나노로봇으로 인하여 발생 가능한 해악들을 방지하기 위한 규율 체계를 구축할 필요가 있다고 보았다. 마지막으로는 위와 관련한 미국 및 유럽에서의 규율 제도를 비교법적으로 살펴보았으며, 이를 반영한 입법적 개선방안에 대해 제언하였다. 전술하였듯 우리는 항상 새로운 기술의 도입에 있어 발생 가능한 생명윤리적 문제들을 검토할 필요가 있다. 기술발전 속도에 비해 이른바 윤리발전 속도가 따라가지 못함에 따른 위험성은 전 세계적으로 여러 선례를 통해 목격ㆍ체감할 수 있었던 바이다. 인간의 생명ㆍ생활 증진을 위한 의료과학 기술 발전에 급급하기보다는, 그로 인해 파생될 수 있는 생명윤리적 쟁점들을 항상 고심하고 경계하여야 한다. 따라서 앞서 연구한 바와 같이 예상되는 해악들을 방지하기 위한 선제적인 입법 및 규제 제도 완비를 통해, 기술발전과 생명윤리가 병존하는 이른바 ‘생명 윤리적인 의료과학 기술 발전’을 이루어야 한다. The surgery is an operation being directly connected to human life. People constantly have researched to prevent negative effects from surgery and to maximize its positive effects. Following from the development of modern medical engineering and robot technology, the use of surgical robots arises as an alternative. Korea as a robotics powerhouse is leading the world with respect to the research of surgical robots. Among the fields of surgical robots, the most active research field is the field of nano-robots. However we should be careful of the problems of bioethics, which can make increase of danger in technology, along with the development of the technology. Especially, the jurists handling the law have to lead legislative discussion that prevents abuse of the technology with respect to the introduce of the technology and that is the mission of the jurists. Thus, regarding to awareness of the problem, we suggest a plan to enhance benefits for doctors as well as patients with respects to the solutions that prevent bioethical negative effects caused by medical nano-robots by using comparative methods. This study limits the range of medical nano-robots, which the robots move around in the body to carry medicine to cure a disease. These medical nano-robots have properties as ① medicine itself as well as ② surgical robots. The negative effect that medical nano-robots can bring is at first a danger of nanoparticle. This can be seen as a perspective of principle of non-maleficence and prohibition of prevention. If we consider toxicity of nanoparticle itself and possibility of being cumulative in human body, it is inevitable to have dangerousness of nano-robots itself and they might involve unknown dangerousness since we do not understand whole mechanism of nano-stuffs. Thus, regrading to expected negative effects we need to establish regulations and clear standards to minimize the negative effects. Second, we consider bioethical issues related to the clinical trial of nano-robots surgery. Since the medical nano-robots are not only new surgical methods but also they have properties of being new medicines, they have to process clinical trial necessarily. That being said, bioethical issues arise such as ① informed consent, ② respect for human vulnerability, and ③ a procedural issue in clinical trial. As long as we resolve above bioethical issues related to clinical trial, we can conduct the clinical trial under having patients’ autonomy so that we can protect patients’ health directly and indirectly. Third, we review distributive justice. Since the research of surgery and medical treatment is in itself connected to human lives and health as root values, distributive justice has to be realized. High technologies such as medical nano-robots can make inequality caused by differences in economical power, but if we realize generalization in its technology so that the technology is being used everywhere, it is shortcut to realize distributive justice. In order to realize distributive justice for medical service such as nano-robot technology, we need declaration and system set-up for that. In order to suggest legislative improvement plan to prevent those negative influences, we examined legislative circumstance of our country. As a result, we could not see any individual law of regulating medical nano-robots and also we saw that the regulation might exist in 「The Law of Medical Equipment」 and 「The Pharmaceutical Law」 but not clear. The author has claimed that medical nano-robots can be seen as medical devices under assumptions that they are not simple medicines but robots having ability to do something, so that they have to be included to be regulated by the laws of 「The Law of Medical Equipment」. In addition, plus the regulation as medical robots and nano-materials, we need to establish systems of regulation to prevent negative effects caused by medical nano-robots. Lastly, we have a look regulation systems in USA and Europe related to above issues by using comparative methods, and suggest legislative improvement plan reflecting those issues. As we said, we always need to consider bioethical issues regrading to the introduce of new technology. The danger of not being able to follow the speed of development of technology compared to that of ethic could be seen everywhere from precedents. We have to keep in mind and be careful of bioethical issues caused by development of medical science. Therefore, in order to prevent negative effects from the technology, we have to achieve so-called ‘bioethical development of medical science and technology’ through setting up anticipative regulations.

Characterization of nano oxaliplatin prepared by novel Fat Employing Supercritical Nano System, the FESNS^®

Lee, Seung-Jae,Kim, Young-Hoon,Lee, Sang-Heon,Hahn, Mikyoung Informa Healthcare 2012 PHARMACEUTICAL DEVELOPMENT AND TECHNOLOGY Vol.17 No.2

<P><I>Background</I>: Oxaliplatin has long been used for the treatment of colorectal cancer via intra-venous infusion. In order to improve patient compliance, a solid dosage form for oral administration of oxaliplatin was prepared as nano-sized particles.</P><P><I>Method</I>: Nano oxaliplatin was prepared employing Fat Employing Supercritical Nano System (FESNS<SUP>®</SUP>) with Supercritical Fluid (SCF) apparatus by using myristyl alcohol as solvent. Morphology of nano oxaliplatin was examined by Scanning Electron Microscopy (SEM), and the particle size and zeta potential were confirmed with Dynamic Light Scattering (DLS). To characterize the nano oxaliplatin particles, solubility rate and in vitro efficacy study (MTS growth inhibition assay) were investigated compared to crude oxaliplatin as reference.</P><P><I>Result</I>: FESNS<SUP>®</SUP> provided reproducible nano oxaliplatin with high manufacturing yield (> 95%). SEM images showed that the particle size distribution of nano oxaliplatin ranged between 20 and 400 nm with the medium particle sizes (<I>d</I><SUB>50</SUB>) of about 164 nm determined by DLS. Pertaining to the long-term stability, no recrystallization of the nano oxaliplatin was observed with negative zeta potential in the state of solution. Nano oxaliplatin was completely dissolved within a couple of minutes in pH 4.0 and pH 6.8 buffer solutions while crude oxaliplatin took a couple of hours to go into solution. In case of MTS growth inhibition assay, the average concentration required to inhibit 50% of cell growth (GI<SUB>50</SUB>) of nano oxaliplatin was decreased by about 45% in comparison to the crude oxaliplatin.</P><P><I>Conclusion</I>: These results lead us to conclude that nano oxaliplatin would have a great potential for the improvement of efficacy and toxicity in human colorectal cancer treatment compared to the crude oxaliplatin.</P>

Retention Characteristics of Nano-Floating Gate Capacitor with SiC Nano-Particles

이동욱,이태희,김은규 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.6

A nano-floating gate capacitor with SiC nano-particles embedded in a SiO2 layer was fabricated and its electrical properties such as the capacitance-voltage hysteresis curve at various temperature, and the retention were characterized. The SiC nano-particles in the SiO2 layer were formed by magnetron sputtering of SiC and SiO2 targets and post-annealing at 900 ˚C for 3 min. They had a spherical shape with an average diameter of 3 s 5 nm and were distributed between the tunnel oxide and the control oxide layers. For the nano-floating gate capacitor with SiC nano-particles embedded in a SiO2 layer, the flat-band voltage shift decreased from 2.2 V at 25 ˚C to about 1.6 V at 85 ˚C and 0.6 V at 125 ˚C, when the gate voltages were swept from −8 V to 8 V. Also, the memory window under the programming/erasing operation at +12 V and −12 V for 700 ms appeared to be approximately 0.54 V at 25 ˚C, 0.61 V at 85 ˚C, and 0.22 V at 125 ˚C after 1 hr. A nano-floating gate capacitor with SiC nano-particles embedded in a SiO2 layer was fabricated and its electrical properties such as the capacitance-voltage hysteresis curve at various temperature, and the retention were characterized. The SiC nano-particles in the SiO2 layer were formed by magnetron sputtering of SiC and SiO2 targets and post-annealing at 900 ˚C for 3 min. They had a spherical shape with an average diameter of 3 s 5 nm and were distributed between the tunnel oxide and the control oxide layers. For the nano-floating gate capacitor with SiC nano-particles embedded in a SiO2 layer, the flat-band voltage shift decreased from 2.2 V at 25 ˚C to about 1.6 V at 85 ˚C and 0.6 V at 125 ˚C, when the gate voltages were swept from −8 V to 8 V. Also, the memory window under the programming/erasing operation at +12 V and −12 V for 700 ms appeared to be approximately 0.54 V at 25 ˚C, 0.61 V at 85 ˚C, and 0.22 V at 125 ˚C after 1 hr.

Charging Effect of WSi2 Nano-particles Embedded in SiO2 Layers

Ki Bong Seo,이동욱,Tae Hee Lee,김은규 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.3

A nano-floating gate capacitor with WSi2 nano-particles embedded in a SiO2 layer was fabricated. The WSi2 nano-particles were formed from a thin WSi2 layer during a rapid thermal annealing process, and they had a spherical shape with an average diameter of 2.5 nm. The electrical properties of the nano-floating gate capacitor with WSi2 nano-particles embedded in SiO2 dielectrics were characterized by using capacitance-voltage measurements. Then, a flat-band voltage shift of up to 3.8 V due to carrier charging of the WSi2 nano-particles appeared when the gate voltage was swept from –7 V to +7 V and from +7 V to –7 V, which showed that the WSi2 nano-particles could be applied to nonvolatile memory devices. A nano-floating gate capacitor with WSi2 nano-particles embedded in a SiO2 layer was fabricated. The WSi2 nano-particles were formed from a thin WSi2 layer during a rapid thermal annealing process, and they had a spherical shape with an average diameter of 2.5 nm. The electrical properties of the nano-floating gate capacitor with WSi2 nano-particles embedded in SiO2 dielectrics were characterized by using capacitance-voltage measurements. Then, a flat-band voltage shift of up to 3.8 V due to carrier charging of the WSi2 nano-particles appeared when the gate voltage was swept from –7 V to +7 V and from +7 V to –7 V, which showed that the WSi2 nano-particles could be applied to nonvolatile memory devices.

Analysis of compaction and sintering behavior of 316L stainless steel nano/micro bimodal powder

Oh, Joo Won,Ryu, Seung Kyu,Lee, Won Sik,Park, Seong Jin Elsevier 2017 Powder Technology Vol.322 No.-

<P><B>Abstract</B></P> <P>Nano powder had various advantages on powder metallurgy process. However, because of its high price and difficulties in treatment, nano powder cannot be easily applied to the field. As a result, nano/micro bimodal powder has been introduced to overcome such problems. In this study, the effects of nano powder ratio in nano/micro bimodal powder on powder metallurgy process have been investigated. The master sintering curves for the bimodal powders were also developed for the first time. With micro, nano and 3 different bimodal powders, compaction behavior was investigated, and dilatometric sintering was carried out to analyze the densification behavior during the sintering process. The results showed bimodal powders had relatively high green density, and the highest value was obtained with 25% nano bimodal powder. The powder also provided the highest densification parameter. Based on the dilatometer data, the master sintering curves of each powder were constructed, and all curves were consistent with experimental data.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nano powder effect in bimodal powders on powder metallurgy process was analyzed. </LI> <LI> 25% nano bimodal powder had the highest green density with bimodal packing effect. </LI> <LI> 25% nano bimodal powder had the highest densification parameter during sintering. </LI> <LI> Bimodal powders showed two-peak sintering behavior due to the nano powder. </LI> <LI> Master sintering curves were well-developed for nano/micro bimodal powders. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>