中村 一希

電子写真感光体では，Alドラム基板と電荷発生層 (CGL) の間に，基板からCGLへの電荷リーク防止や，CGL内の不要電荷の除去などを行う下引き層 (UCL) が用いられている．UCL材料には一般的にはZnO等の金属酸化物が用いられているが，金属酸化物微粒子を含有するUCLに色素を添加すると，感光体中の残留電位の上昇が軽減され安定性が増すといった効果が得られている．本研究ではZnOをベースとしたUCLの電気伝導メカニズム，色素の添加効果を明らかにすることを目的として，熱刺激電流ならびに電気特性の解析を行った．

電子写真感光体では，Alドラム基板と電荷発生層 (CGL) の間に，基板からCGLへの電荷リーク防止や，CGL内の不要電荷の除去などを行う下引き層 (UCL) が用いられている．UCL材料には一般的には電子輸送性の金属酸化物が用いられているが，金属酸化物微粒子を含有するUCLに色素を添加すると，感光体中の残留電位の上昇が軽減され安定性が増すといった効果が得られている．本研究では金属酸化物をベースとしたUCLの電気伝導メカニズムや色素の添加効果を明らかにすることを目的として，交流インピーダンス測定ならびに過渡光電流測定を用いた解析を行った．

帯電制御剤 (CCA) として正帯電型の4級アンモニウム―スルホン酸塩，コア粒子にそれぞれ平均粒径110nmおよび12nmの疎水性シリカおよび平均粒径140nmの疎水性炭酸カルシウムを用いて外添CCAを作製した．スチレンアクリル樹脂のモデルトナーに外添CCAを1%添加し，またコア粒子へのCCAコート量を調整して，CCA添加量を変化させ，帯電量のCCA添加量依存性を検討した．<br>帯電量はCCA添加量の増加とともに劇的に増加し，110nmおよび140nmのコアにCCAを被覆した外添CCAではCCA濃度0.03µmol/g付近に，12nmのコアに被覆した外添CCAでは0.35mol/g付近に明瞭な変曲点が観測され，変曲点より高濃度域では帯電量は飽和した．<br>変曲点でのCCAのコアに対する被覆率はコア粒径よらず17-25%であった．被覆率25%程度での帯電量の飽和は，コア粒子からのCCAの剥離とキャリアへの付着，CCA分子間相互作用による帯電効率の低下などが考えられた．

The bio-organic thin film transistor (BiOTFT) with the DNA and DNA-surfactant complex as a dielectric layer shows memory function. In order to investigate the effect of surfactant structure on the OTFT memory device performance, different kinds of surfactant were introduced. Cetyltrimethylammonium chloride (CTMA), Lauroylcholine chloride (Lau) or Octadecyltrimethylammonium chloride (OTMA) as the cationic surfactant was mixed with DNA to prepare the DNA complex through the electrostatic interaction. In addition, the different molecular weight DNA also has been studied to analyze the effect of DNA chain length on the performance of the physical property. Many kinds of methods including UV-vis, Circular dichiroism (CD), I-V characteristic and atomic force microscope (AFM) have been applied to analyze the property of DNA complex. In conclusion, all of DNA complex with CTMA, OTMA and Lau were revealed to work as the bio-organic thin film transistor memory, and the device fabricated by Lau has the highest ON current and showed better device performance. © 2012 SPIE.

Multi-functional composite film showing thermoresponsive absorption and emission was demonstrated by using thermochromic leuco dye, developer and luminescent Europium(III) complex; the coloration and bleaching of the leuco dye enabled control of the photoluminescence of the Eu(III) complex by thermal stimuli.

We prepared solid-state electrochromic (EC) cells based on phthalate derivatives and containing a gel electrolyte. The cells showed vivid color changes via electrochemical reactions, i.e., from being water transparent to assuming one of the three primary colors (cyan, magenta, and yellow). Moreover, we obtained continuous-tone images by using the three primary-color EC cells. The formation of continuous-tone images by using the EC cells was realized by applying a rectangular-wave voltage with various duty ratios. In addition, according to a subtractive color-mixture process, we obtained multiple color representations, including intermediate red, green, and blue colors, by stacking two of the three primary-color EC cells. ©2012 Society for Imaging Science and Technology.

Electrochromism is known as electrochemical reaction exhibiting coloration, and is applicable to a new imaging device. In this paper, we prepared novel modified electrode using Si coupling agent on ITO deposit. Novel modified electrode achieved better memory effect and lower coloration potential in comparison with previous modified electrode using TiO2.

Novel multicolor electrochromic (EC) device with on electrochemical silver deposition mechanism was successfully demonstrated. The novel EC device enabled reversible color change between transparent, red and blue color in a single cell by using voltage step method which controlled the size of deposited Ag nanoparticles.

We studied the electrochromic (EC) properties of the cross-linked phthalate polymer [polyethylene terephthalate (PET) derivative]-modified electrode. PET showed a vivid color change from clear colorless to magenta by electrochemical reduction as similar to dimethyl terephthalate (DMT) reported previously, because PET contains DMT moieties in the main chain. The PET film-modified electrode exhibited better coloring and memory properties than DMT. Cross-linked PET-modified electrode achieved good coloring characteristics and switching stability. It is revealed that phthalate polymer showed good EC properties than phthalate monomer. © 2011 John Wiley & Sons, Ltd.