PAPER: Thermal convections break the incoming mist: A new method for synthesis of nanoparticle layer. 熱対流がミストを微細化。ナノ粒子層の新規合成法

Discovery of a low-energy route to layer of nanometer-sized particles with high crystallinity. 高結晶性を有するナノ粒子層への「省エネプロセス」の発見。 Continue reading PAPER: Thermal convections break the incoming mist: A new method for synthesis of nanoparticle layer. 熱対流がミストを微細化。ナノ粒子層の新規合成法

PAPER: Spraying water-soluble particles to komatsuna leaves. 小松菜に水溶性微粒子を散布したら・・

Short Introductions of /our papers/


Free-access (until Dec. 1, 2017): elsevier.com

Komatsuna plants were grown and exposed to ammonium sulfate (((NH4)2SO4), AS) submicron particles for 16 days (22.5 µg m−3 per day) in phytotrons.

The amount of particles deposited on the leaf  decreased over time, because AS particles deposited on the leaf deliquesced, allowing ions such as SO42− in the solution to be absorbed into the leaf. 葉表面に堆積した粒子の量は時間とともに減少した。サブミクロン硫酸アンモニウム(AS)粒子が葉表面に堆積し、脱離溶液中のSO42−などのイオンが葉に吸収される可能性が高い。

Continue reading “PAPER: Spraying water-soluble particles to komatsuna leaves. 小松菜に水溶性微粒子を散布したら・・”

PAPER: Plant leaf waxes to prevent deposition of particles. 大気中微粒子の付着を防止する葉面のワックス結晶

Other “intro” of papers from our lab >> /tag/paper/


Journal of Plant Research (13 June 2016) DOI 10.1007/s10265-016-0839-7
plants-Fuchucampus“Effect of epicuticular wax crystals on the localization of artificially deposited sub-micron carbon-based aerosols on needles of Cryptomeria japonica (Sugi)”

電界放出型走査電子顕微鏡(FE-SEM)によるスギ(代表的な日本の針葉樹種)の葉表面に人工的に散布されたサブミクロンサイズの炭素系粒子の局在を調べました。気孔の機能を保持するために、密に分布されたエピクチクラワックスワックス結晶は、気中からの微粒子の付着を防止する役割があるかもしれません。from-nakaba-2016-JPlantRes

Elucidation of the mechanism of adsorption of particles suspended in the gas-phase (aerosol) to the outer surfaces of leaves provides useful information for understanding the mechanisms of the effect of aerosol particles on the growth and physiological functions of trees. We examined the localization of artificially deposited sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica, a typical Japanese coniferous tree species, by field-emission scanning electron microscopy (FE-SEM).  Our results suggest thatepicuticular wax crystals affect distribution of carbon-based particles on needles. Therefore, densely distributed epicuticular wax crystals might prevent the deposition of sub-micron-sized carbon-based particles on the surfaces of needles of Cryptomeria japonica to retain the function of stomata.


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Continue reading “PAPER: Plant leaf waxes to prevent deposition of particles. 大気中微粒子の付着を防止する葉面のワックス結晶”

PAPER: “Re-use” enzyme with polymer nanofiber, 高分子ファイバーで酵素の固定化と再利用

Other “intro” of papers from our lab >> /tag/paper/ Immobilisation of enzyme into synthetic resin nanofibres via electrospinning. 電界紡糸法(エレクトロスピニング)による酵素の樹脂中への固定化 Biotechnology Reports, 10, 2016, 44–48 OPEN ACCESS >>  dx.doi.org/ Resin樹脂: Polyvinyl alcohol. 親水性が強い。 Enzyme酵素: cyclodextrin glucanotransferase。グルコースのオリゴ糖が環状となった構造で、食品、医薬に使用。 Highlights: * Fabrication of enzyme-carrying polymeric nanofibers by electrospinning. * PVA nanofibers structure and size were not affected by the addition of enzyme. * Enzyme/PVA nanofibers show excellent immobilisation efficiency. Related topics. … Continue reading PAPER: “Re-use” enzyme with polymer nanofiber, 高分子ファイバーで酵素の固定化と再利用

PAPER: Removal of particles from potable water. 水道水(飲料水)から微粒子を採集

Other “intro” of papers from our lab >> /tag/paper/


stock-photo-water-pouring-from-a-jug-into-a-glass-on-blue-95668024Removal of iron-oxide particles after post-filtration in local potable water using an electrophoretic method

Collaborated with: Univ. Putra Malaysia; Univ. Teknologi MARA, Malaysia

Journal of Water Process Engineering: Vol. 9, Feb. 2016, Pages 208–214. doi:

Full text/PDF: Researchgate, or here

Keywords: Elnaim2016-waterectrophoretic deposition; Fibre electrodes; Limiting flux; Iron oxide; Zeta potential

Recent journal articles from our group.研究室から発表した(最近の)論文1288741555_themes

Continue reading “PAPER: Removal of particles from potable water. 水道水(飲料水)から微粒子を採集”

PAPER: Charge of Particle by Kelvin Probe Force Microscopy. ケルビンフォース顕微鏡で粒子の帯電を計測

Other “intro” of papers from our lab >> /tag/paper/ A collaborated study with Dr. Okuda group at Keio University. エアロゾル研究 Vol. 30 (2015) No. 3 p. 190-197 (Journal of Aerosol Research) doi.org/ | ResearchGate Kelvin Probe Force Microscopyを用いたエアロゾル個別粒子の帯電状態の測定 Measurement of the Electrostatic Charging State of Individual Particles in Ambient Aerosol Using Kelvin Probe Force Microscopy (Okuda, Gunji, Lenggoro)   呼吸により人体に入る微粒子に関する課題において、微粒子の帯電状態が注目されるようになった。本研究では大気中に浮遊する微粒子の帯電状態を評価できる新たな手法を考案した。大気環境中から捕集された微粒子の表面電位を測定し、その微粒子の電荷素量が4以上であることが明らかになった。今後は化学組成と帯電状態との関係を検討していく必要も考えられる。 Recently, the importance of electrostatic charging state to particle … Continue reading PAPER: Charge of Particle by Kelvin Probe Force Microscopy. ケルビンフォース顕微鏡で粒子の帯電を計測

PAPER: Charge of particles (PM2.5) collected in filter, 捕集された大気粒子の帯電状態

Other “intro” of papers from our lab >> /tag/paper/AJAE-cover


Preliminary study on the measurement of the electrostatic charging state of PM2.5 collected on filter media, 
実環境中のPM2.5(粒子状物質)をフィルター状で捕集したあとに帯電状態を調べた。「帯電」は、PMによる健康への影響を理解するために重要な情報。捕集されたPM2.5は75~87%が負に帯電されたことがわかった。

共同研究の成果 Collaborated between:
* Keio Univ: Okuda (Prof.), and graduate students (Yoshida, Gunji, Okahisa) and
* Tokyo Univ. of Agr. & Tech.: Kusdianto (Doctoral-student), Gen (Doctoral-student), Sato (Master-student), Lenggoro (Prof.)

keio-collected-tuat-measured
Schematic of experiments

Asian Journal of Atmospheric Environment (2015) 9(2):105-113 … more…
Continue reading “PAPER: Charge of particles (PM2.5) collected in filter, 捕集された大気粒子の帯電状態”

PAPER: Fine particles on bio-composite surface. ココナツ殻由来素材の表面に微粒子を集積

Other “intro” of papers from our lab >> /tag/paper/

 


Open article in PDF

HIGHLIGHTS:
* Physical treatment on the biocomposite increases the surface roughness.
* Single bond COOH network on the treated biocomposite promotes the particle deposition.
* The network reduces the particles repulsion during the deposition process.

1-s2.0-S0921883114002970-gr1

# Bio-composite(バイオコンポジット)is a composite material formed by a matrix (resin) and a reinforcement of natural fibers.生物由来素材を組み合わせて作った素材

A nanostructure derived from TiO2 particle deposition onto a biocomposite surface derived from coir dust (ココナッツ廃棄物) was developed to control degradation. The coir dust was obtained from coconut kernel waste (ココナツ殻の廃棄物) and underwent drying treatment before it was mixed with polypropylene (PP) as the substrate. The TiO2 suspension was spray dried onto a hot-pressed substrate (biocomposite) with a surface roughness between 0.23 and 1.57 μm.

DOI: http://dx.doi.org/10.1016/j.apt.2014.11.006
Open article in PDF

Advanced Powder Technology (詳細・・・) Continue reading “PAPER: Fine particles on bio-composite surface. ココナツ殻由来素材の表面に微粒子を集積”

PAPER: Particle-dispersion then Raman spectroscopy: a new surface analysis method. 粒子集積の後にラマン分光法。新しい表面分析法を提案

Other “intro” of papers from our lab >> /tag/paper/


* Main researcher: Masao Gen,  a doctoral student: 2011/10-2014/6. Joined Tohoku University (2014-2015, Researcher/Assistant professor), then City Univ. of Hong Kong. He applied this new method (Electrospray-Surface Enhanced Raman Spectroscopy (ES-SERS) for probing particulate matter (PM) collected as “air pollutant” Atmos. Chem. Phys. (2017)

pdf

M. Gen & I. W. Lenggoro, RSC Adv. (2015)
M. Gen & I. W. Lenggoro, RSC Adv. (2015)

Aerosol nanoparticle sensor system for probing a dip-coated layer of organic molecules, at sub-100 nm resolution .気中分散微粒子を用いたSERS法によって、表面上の分子「パターン」に対して直接「検査」可能な技術

関連技術 Related topics: 残留農薬の検出に向けて, Detect a pesticide in the field.

There’s more…さらに詳細に

PAPER: A “green” synthesis route to battery material. 電池用粉末「省資源」合成法

Other “intro” of papers from our lab >> /tag/paper/ Lithium manganese oxide (LiMn2O4) powders with particle sizes in the range of 100 nm – 600 nm have been synthesized through glucose-assisted combustion synthesis. The presence of glucose increases the stability of the precursor solution, purity of the heat-treated powders, and decreasing on size of the synthesized particle. (植物由来原料)グルコースを添加した「燃焼合成法」により二次電池用粉末 グルコースの添加により、熱処理される前の粉末の前駆体(LiとMnの溶液)の「安定性」が向上し、合成された粒子の微粒化(サイズ減少)にも効果的。100~600 nmの範囲の粒径を持つリチウムマンガン酸化物(LiMn2O4)粉末が合成できました。 OPEN ACCESS: dx.doi.org/10.2109/jcersj2.122.976 Journal of the … Continue reading PAPER: A “green” synthesis route to battery material. 電池用粉末「省資源」合成法

PAPER: Relation of Charged Particles & Substrate’s Hydrophilicity. 正帯電した気中浮遊粒子が親水性が高い表面に付く

Area-selective deposition of charged particles derived from colloidal aerosol droplets on a surface with different hydrophilic levels.Journal of Aerosol Science, 2014. by Kusdianto (Doctoral student), Gen (Doctoral student), and Lenggoro Highlights * Charged aerosol particles were derived from spraying colloidal droplets. * Substrate with different ‘levels’ of hydrophilicity was used. * Positively charged aerosol particles tended to approach the ‘more hydrophilic’ area. * Association found between … Continue reading PAPER: Relation of Charged Particles & Substrate’s Hydrophilicity. 正帯電した気中浮遊粒子が親水性が高い表面に付く

PAPER: Insertion of particles in sub 100 nm holes, in water. [世界初]100nm以下の穴に水中浮遊粒子の固定化

Immobilization of colloidal particles into sub-100 nm porous structures by electrophoretic methods in aqueous media Kusdianto, Sasaki, Naim, Lenggoro, Colloids Surfaces A: 10.1016/j.colsurfa.2014.06.042 【新規性】新開発の「パルス型電気泳動法(Pulse-type Electrophoretic Deposition/EPD)」および従来EPD法を用いて、水中に浮遊する粒子を100nm以下の穴(ポーラス構造)に挿入・固定。世界初です。 【耐久性】ポーラス構造内に固体化された粒子に対して、超音波エネルギーをかけて、粒子の脱離を試みましたが、穴に粒子がちゃんと残こります。 【展開】酵素や触媒材料の固定化技術への応用 Full article RELATED TECHNOLOGY: 関連技術・成果 Submicrometer- and nanometer-sized particles 2D structure from colloids, 電界による粒子の2次元構造化:凝集状態の制御 Particles with high-crystallinity by-electric field in liquid-phase, 電界による高結晶粒子の構造化:クラックが少ない構造体も可能 Continue reading PAPER: Insertion of particles in sub 100 nm holes, in water. [世界初]100nm以下の穴に水中浮遊粒子の固定化