http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Duong, Dinh Loc,Lee, Il Ha,Kim, Ki Kang,Kong, Jing,Lee, Seung Mi,Lee, Young Hee American Chemical Society 2010 ACS NANO Vol.4 No.9
<P>The mechanism of doping carbon nanotubes (CNTs) with a salt solution was investigated using the density functional theory. We propose that the anion−CNT complex is a key component in doping CNTs. Although the cations play an important role in ionizing CNTs as an intermediate precursor, the ionized CNTs are neutralized further by forming a stable anion−CNT complex as a final reactant. The anion−CNT bond has a strong ionic bonding character and clearly shows p-type behavior by shifting the Fermi level toward the valence band. The midgap state is introduced by the strong binding of carbon and anion atoms. These localized charged anion sites are highly hygroscopic and induce the adsorption of water molecules. This behavior provides a new possibility for using anion-functionalized CNTs as humidity sensors.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2010/ancac3.2010.4.issue-9/nn1011489/production/images/medium/nn-2010-011489_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn1011489'>ACS Electronic Supporting Info</A></P>
Efficacy of electrochemically activated water solution in gingivitis treatment
Dinh‑Toi Chu,Van‑Huy Pham,Thien Chu‑Dinh,Truong Nhu Ngoc Vo,Duc Long Duong,Van Nhon Bui,Minh Son Tong,Thi Thu Phuong Nguyen,Quynh Anh Le,Khanh‑Hoang Nguyen 한국약제학회 2019 Journal of Pharmaceutical Investigation Vol.49 No.3
Mouthwash is one of the most commonly oral healthcare products for prevention and treatment of gum diseases. Dr. ECA is a disinfectant solution manufactured by a Vietnamese company and has been licensed for oral healthcare, but its effect on gingivitis is still unclear. To evaluate the effectiveness of this product in the treatment of gingivitis, we conducted a clinical study in 60 students diagnosed with gingivitis to compare the results of gingivitis treatment using Dr. ECA and a control mouthwash (a demonstrated anti-gingivitis product). The data showed that in the treated group, the rate of good Gingivitis Index (GI) before treatment was 46.67%, but after 2 and 4 weeks of using Dr. ECA that rate was increased to 96.67% and 100%, respectively. The percentage of patients with bleeding on probing was 63.33% but declined sharply after 2 weeks of treatment to 6.67%, and further reduced to 3.33% after 4 weeks of treatment. The treatment outcomes in were similar in the Dr. ECA treated group and control one with no statistically significant difference. Our results suggest that the electrolyte saline solution Dr. ECA is effective in treating gingivitis. Its effects are similar to other mouthwash products that had been approved and marketed.
Probing graphene grain boundaries with optical microscopy
Duong, Dinh Loc,Han, Gang Hee,Lee, Seung Mi,Gunes, Fethullah,Kim, Eun Sung,Kim, Sung Tae,Kim, Heetae,Ta, Quang Huy,So, Kang Pyo,Yoon, Seok Jun,Chae, Seung Jin,Jo, Young Woo,Park, Min Ho,Chae, Sang Hoo Nature Publishing Group, a division of Macmillan P 2012 Nature Vol.490 No.7419
Grain boundaries in graphene are formed by the joining of islands during the initial growth stage, and these boundaries govern transport properties and related device performance. Although information on the atomic rearrangement at graphene grain boundaries can be obtained using transmission electron microscopy and scanning tunnelling microscopy, large-scale information regarding the distribution of graphene grain boundaries is not easily accessible. Here we use optical microscopy to observe the grain boundaries of large-area graphene (grown on copper foil) directly, without transfer of the graphene. This imaging technique was realized by selectively oxidizing the underlying copper foil through graphene grain boundaries functionalized with O and OH radicals generated by ultraviolet irradiation under moisture-rich ambient conditions: selective diffusion of oxygen radicals through OH-functionalized defect sites was demonstrated by density functional calculations. The sheet resistance of large-area graphene decreased as the graphene grain sizes increased, but no strong correlation with the grain size of the copper was revealed, in contrast to a previous report. Furthermore, the influence of graphene grain boundaries on crack propagation (initialized by bending) and termination was clearly visualized using our technique. Our approach can be used as a simple protocol for evaluating the grain boundaries of other two-dimensional layered structures, such as boron nitride and exfoliated clays.
van der Waals Layered Materials: Opportunities and Challenges
Duong, Dinh Loc,Yun, Seok Joon,Lee, Young Hee American Chemical Society 2017 ACS NANO Vol.11 No.12
<P>Since graphene became available by a scotch tape technique, a vast class of two-dimensional (2D) van der Waals (vdW) layered materials has been researched intensively. What is more intriguing is that the well-known physics and chemistry of three-dimensional (3D) bulk materials are often irrelevant, revealing exotic phenomena in 2D vdW materials. By further constructing heterostructures of these materials in the planar and vertical directions, which can be easily achieved <I>via</I> simple exfoliation techniques, numerous quantum mechanical devices have been demonstrated for fundamental research and technological applications. It is, therefore, necessary to review the special features in 2D vdW materials and to discuss the remaining issues and challenges. Here, we review the vdW materials library, technology relevance, and specialties of vdW materials covering the vdW interaction, strong Coulomb interaction, layer dependence, dielectric screening engineering, work function modulation, phase engineering, heterostructures, stability, growth issues, and the remaining challenges.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2017/ancac3.2017.11.issue-12/acsnano.7b07436/production/images/medium/nn-2017-074362_0021.gif'></P>
Duong, Hong Dinh,Shin, Younsook,Rhee, Jong Il Elsevier 2019 Microchemical journal Vol.147 No.-
<P><B>Abstract</B></P> <P>In this study, two typical pH-sensitive dyes, fluorescein amine (FA) and 8‑hydroxypyrene‑1,3,6‑trisulfonic acid trisodium salt (HPTS), were doped with two types of silica particles. The dye-doped silica particles were entrapped in a mixture of 3‑glycidoxypropyltrimethoxysilane (GPTMS) and 3-aminopropyltrimethoxysilane (APTMS) sol-gel matrix (GA) and a polyurethane hydrogel (PU) to prepare stable pH-sensitive membranes in a microtiter plate. Four pH-sensing membranes prepared at the bottom of wells in 24-well microtiter plates showed high sensitivity, fast recoverability, and good photostability. Supporting materials with fast ion transport properties were used to produce a pH-sensing membrane with rapid response time. The membranes entrapped with FA-doped silica particles had a dynamic detection range from pH 2 to pH 6, while the membranes entrapped with HPTS-doped silica particles had a dynamic detection range from pH 5 to pH 8. Dye-leaching from the pH-sensing membranes did not occur due to tight binding of functional groups in the dyes (FA and HPTS) to the sol-gel GA matrix, the doping of dyes in the silica particles, and the addition of an anti-fading agent (DABCO). Four pH-sensing membranes were used to measure the pH of wastewater. The measured results were consistent with standard pH values.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Development of fluorescent pH sensors for acidic and neutral pH ranges </LI> <LI> Fabrication of a pH-sensing membrane with FA-doped silica particles for the pH range of 2–6 </LI> <LI> Fabrication of a pH-sensing membrane with HPTS-doped silica particles for the pH range of 5–8 </LI> <LI> Application of the pH-sensing membranes to monitor the pH values of wastewater </LI> </UL> </P>