十八胺说明书

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十八胺的性质及防腐

十八胺应用中的若干技术问题探讨之勘阻及广创作Approach to several technic issues about the application of octadecylamine film陈进生、王杭州、钟爱民厦门嵩屿电厂（厦门 361026）摘要：根据十八胺的特性与应用现状, 总结应用中的工艺经验, 提出十八胺防腐时应注意的若干技术问题.关键词：十八胺；热力设备；停用呵护剂Abstract：According the properties and application status of octadecylamine, the experiences of utilization are summarized, several technic issues which should be paid attention are presented.Key words：octadecylamine film；thermal power equipment；shutdown anticorrosion preservative1引言十八胺（ODA, C18H39N, octadecylamine）是一种具有良好特性的成膜胺.十八胺的分子结构中含有亲水端和憎水端, 在汽水系统中, 其分子上的亲水端吸附于金属概况, 开成单分子膜, 而分子上的憎水端则排斥水分子, 在介质与金属概况形成一层呵护膜.目前国内很多电厂, 已应用此项技术进行机组停用呵护, 并取得一定的效果.但由于十八胺应用中影响呵护效果的技术因素较多, 如应用工艺、药品的热分解特性、汽液相的分配系统、对凝结水精处置混床树脂的影响等, 如果这些影响因素未获得重视, 并采用相应的对策, 那么, 呵护效果就难以获得有效控制, 甚至会呈现药剂在热力系统内部概况析出、树脂受到污染等问题.本文以十八胺在厦门嵩屿电厂的试验性应用情况, 结合国内目前的现状, 重点对如何优化十八胺应用工艺, 如何完善十八胺现场使用技术及应用中的注意事项进行探讨.2十八胺的基赋性能2.1主要性状十八胺是白色蜡状或颗粒状物质, 其分子式为C18H39~3, 熔点35~45℃, 凝点是42~50℃, 沸点280~320℃, 闪点130~150℃.工业品中通常含有仲胺和叔胺.十八胺不溶于水, 在75℃的水中呈悬浊液, 但可溶于乙醇, 异丙醇、醋酸, 醚等有机溶剂.十八胺对眼睛和粘膜有安慰性, 生物毒性试验标明十八胺属于无毒类药剂, 每日500mg/L的剂量服用2年, 试验鼠无任何毒性反应.2.2十八胺的热分解对十八胺的分解温度存在一定的争议, 有的报道为450℃, 有的报道为530℃以上.采纳美国TA2000DCS型差示扫描量热仪进行成膜样品的热分解试验, 结果是, 在250℃时, 十八胺的热分解量为10%左右, 320~450℃时热分解量为35%, 分解产物为碳氢化合物、NH3、H2、CH4、CO等.这标明, 在450℃下, 十八具有较好的热稳定性[1].另外, 当温度超越80℃时, 十八胺会发生析氨反应, 即由伯胺转酿成仲胺或叔胺, 释放出NH3, 这一反应随着温度的升高而加快.2.3十八胺的分配系数利用相平衡理论可以近似求出十八胺在气液相中的分配系数约为1, 从理论上说明了十八胺在汽相中不单有呵护效果, 而且呵护效果与液相接近.这也就是十八胺不单可以用于锅炉侧的停运调养, 也可用于汽机侧的停运调养的原因.2.4十八胺对精处置树脂的影响用浓度为的十八胺对强碱型苯乙烯系阴树脂（委胺Ⅰ型, 201×7）进行浸泡试验, 发现在第1天后, 阴树脂的工交年夜幅下降, 只有未浸泡前的一半, 并随十八胺浓度的增加而进一步下降.然后,采纳4%的NaOH溶液对受污染的阴树脂进行复苏, 阴树脂的工交未能获得恢复.因此, 可以认为, 十八胺对阴树脂具有强烈的污染作用, 又由于十八胺的溶解性差, 附着力强, 招致受污染的阴树脂不成用惯例方法复苏[2].所以, 在设有凝结水精处置的高参数机组上, 应慎用十八胺法防腐, 应充沛考虑十八胺对树脂的不成复苏的污染作用.据了解, 在秦皇岛热电厂、嘉兴电厂等设有凝结水精处置的机组上, 应用十八胺时, 均隔绝凝结水精处置系统.3应用工艺技术实际应用中, 确定合适的现场加药工艺至关重要.加药浓度、时间、pH值等因素都对呵护效果发生直接影响.3.1加药的浓度采纳交流阻抗、恒电位阶跃及邻菲罗啉分光光度法对成膜样品进行试验, 发现当十八胺的质量浓度为25mg/L时, 成膜样品的耐腐蚀性最好.随着十八胺浓度的增加, 膜的耐蚀性反而下降[3].考虑到药品在实际系统中的热分解以及各种损失, 十八胺的添加浓度应控制小于50mg/L, 通常的参照使用量是：单机容量300MW 以下每次加药80kg（药品浓度为10%）, 单机容量300MW左右每次加药100kg, 单机容量600MW左右每次加药150kg, 对母管制机组加入量根据实际情况适当增加[4].嵩屿电厂在启动锅炉进行试验性应用时, 控制的总加药量为10kg.应该特别注意的是：十八胺如果用量缺乏, 不单不能形成致密的呵护膜, 金属有可能发生局部腐蚀.可是, 十八胺浓渡过高也会给水汽质量带来不良的影响, 同时造成药品的浪费.3.2药品的pH值一般认为, 溶液pH值在8.5~之间变动时对成膜效果影响不年夜.因为在此pH值范围内, 十八胺的分子结构不会发生明显的变动, 碱性化学水工况运行的锅炉水汽中pH值正好落在此范围内, 适合成膜要求.由于十八胺分子中胺基（-NH2）呈弱碱性, 使用时, pH值略有上升.嵩屿电厂在试验性应用时, 启动锅炉炉水pH值由加药前的上升至加药后9.41.3.3加药的温度由于在450℃下, 十八胺仍具有较好的热稳定性, 分解量小, 因此, 一般在热力系统温度450℃下加药.考虑到实际停机速度等的要求, 在热力系统工作介质温度为500℃以上的工况下, 十八胺的成膜效果仍较为良好的, 只是所加的药量要来很多.外高桥电厂、望亭电厂等电厂实际应用时, 加药时主蒸汽温度在500℃以上, 但仍取得较好的呵护效果.嵩屿电厂试验性应用的加药温度为350℃, 维持MPa左右.3个月后翻开启动锅炉汽包门检查调养效果, 汽包壁上有黑灰色的呵护膜.3.4加药的时间为了使整个热力系统都能够获得呵护, 应保证十八胺在水汽在系统中充沛循环, 并与金属概况充沛接触.因此, 利用正常停炉阶段所继续的时间加药, 并维持2~3h以保证汽水在热力系统中循环3~4次（以300MW发机电组为例）, 以确保成膜效果.3.5加药点及加药方式一般采纳连续加药方式, 并以除氧器出口下降管作为主加药点, 以减少药剂在除氧器中的损失.另外, 可选择主凝水管道作为辅助加药点, 以呵护凝结水系统.有条件的话, 可装置专用的机组停用药剂加药系统.加药前, 应根据加药泵的出力及溶药箱的体积, 计算好加药总体所需的时间.通常是调养刚开始时加年夜药泵的开度, 尔后逐渐减少药泵的开度.4应用时的注意事项4.1十八胺的毒性试验十八胺属于无毒类药剂, 但应注意的是, 国内目前使用的成膜胺一般都不是纯的十八胺, 而是以十八胺为主要成分的混合物或十八胺的衍生物, 它们的毒性与十八胺是不完全相同的, 不能引用十八胺的毒性试验数据作为产物的毒性试验结果, 而必需对每种产物分别做毒性试验, 用户也应要求厂家提供相应的毒性试4.2成膜效果的评价利用十八胺进行热力设备停用呵护的效果评价中, 目前多采纳酸性硫酸铜点滴成膜试片, 结合年夜气流露或腐蚀浸泡试验来作定性评价, 通过观察成膜金属上的酸性硫酸铜滴液的变色时间来判断成膜效果.蓝色溶液变红的时间越长, 膜的耐腐性越好, 呵护效果越显著.4.3成膜的有效期成膜的有效期一般在3个月以内, 尤其是在湿润的气氛下, 要坚持三个月以上的成膜是较为困难的.如果要坚持半年以上的调养效果, 必需在每季度对锅炉焚烧进行重新的成膜调养.4.4成膜金属的洁净度实际应用发现, 十八胺在洁净的金属概况的成膜较为胜利, 但在有垢的水冷壁管和有积水的汽机死角及过热器的弯头成膜效果较差.“成膜”是在洁净的金属概况生成呵护膜, 当金属概况已被垢或者积水所淹没的情况下, 生成膜的基本条件不存在, 膜也就无从生成了.4.5成膜时的化学监督使用十八胺时, 必需对水汽质量进行严格监督, 除惯例项目外, 还必需增加对铁、铜、十八胺浓度等项目的检测.成膜胺在氧存在下, 热分解发生低分子有机酸.机组启动早期, 由于热力除氧效果欠安, 往往给水溶氧量较高, 应引起足够的重视.4.6成膜呵护的范围十八胺停炉呵护方式对凝汽器、凝结水系统防腐效果欠安, 应采纳其它方法或工艺实施有效呵护, 如系统积水应疏放干净, 或采纳热风干燥法进行呵护, 降低系统湿度, 争取系统中相对湿度小于50％, 以保证防腐效果.另外, 十八胺在单一相中成膜优于双相中成膜, 如在纯水相中的省煤器管成膜比在水汽两相的水冷壁管中成膜的效果好, 这一点应引起重视, 以确保水冷壁管的4.7防止树脂受污染实验标明, 十八胺会对凝结水精处置的树脂造成不成逆转的污染.因此, 热力系统成膜呵护前, 应完全退出混床的运行.下一次机组启动后, 应对系统进行完全的冲刷, 并测试出水中确实不含有十八胺后, 方可投入凝结水精处置混床.特别需要说明的是, 如果凝结水精处置混床能够实现氨化运行, 那么在应用十八胺之前, 应进行充沛的研究与试验, 以免对混床氨化运行造成破坏性的影响.参考文献[1]、田文华等．新型热力设备停用呵护剂性能试验研究．中国电力．2001, 34（4）：24~27．[2]、朱志平等．十八胺对阴树脂的污染及对策．热力发电．2001, 2：57~58．[3]、廖强强等．十八完基胺膜的耐腐蚀性评定．中国电力．2001, 34（7）：19~21．[4]、彭伟等．成膜胺应用中的若干问题探讨．华东电力．2002, 5：33~34．第一作者简介陈进生（1970—）, 男, 福建南安人, 1992年结业于武汉水利电力年夜学.现为厦门嵩屿电厂化学主管, 工程师, 武汉年夜学在读工程硕士.。

十八胺停炉保护剂的选择与使用方法

运行、延长锅炉的使用寿命，有着重要的意义。
目前火电厂锅炉停用保护采用的方法主要分为两大类，
即干法保护和湿法保护。干法法、充氮法等。正压吹干保养法需要的初期设备投资较高，保养过程中需要维持

锅炉温度高于环境温度10℃，能耗大，成本较高，大修打开系统时不
欣格瑞sgr0431用量与使用方法?加药量按水汽系统的水容积计算加药量一般为150250mgl按有效浓度计算?使用方法常见的保护工艺是将药剂母液加入除盐水通过机械搅拌稀释几倍在停机前的滑停过程中因要求蒸汽温度小于450防止十八胺大量分解快速将药剂加入热力系统循环1h后停机再经冷却后系统带压放水利用余热烘干锅炉
十八胺锅炉停炉保护剂
火电厂停炉保护的方法与特点
近年来，电力系统许多电厂机组启停频繁，热力设备停运期间的腐蚀保护任务就更为突出。锅炉停用后，外界空气就会大量进入锅炉水系统内，此时锅炉虽已放水，但在锅炉金属表面上总是附着一层水膜，空气中的氧便溶解在此水膜中，以致达到饱和状态，所以很容易引起溶解氧的腐蚀，其腐蚀速度一般要比运行期间快得多。如果锅炉金属表面上有能溶于水膜的盐垢时，则腐蚀性更强烈。实践证明，产生严重腐蚀的锅炉多是停炉期间形成，而在运行中又发展所造成的。因此，在停炉期间采用适当的保护方法，对防止锅炉腐蚀，确保安全

包装与贮存
一般采用25kg或50kg的塑料桶包装，或根据客户需求定制。

技术服务
我司配备有一流的专业技术团队，和一支专门的停炉保护实施队伍，我们期待你们的青睐，有需要我们定当竭诚为您服务！
SGR0430用量与使用方法
SGR0430对锅炉可以湿式保护也可以干式保护。（1）湿式保护：SGR0430非常易溶于水，直接可以通过水流带入系统，搅拌均匀，而后密封系统就可以，建议添加量0.25%-0.5% ，具体用量根据实际状况决定；（2）干式保护：SGR0430可以通过送风管，经过抛洒或喷雾按一定比例引入系统，也可以装入自封袋或放在盘托上，实现停运保护。

复合氨基酸注射液(18)说明书

7.2g
12.2g
16.3g
L—精氨酸
4.9g
8.4g
11.2g
L—天门冬氨酸
1.5g
2.5g
3.3g
L—胱氨酸
0.2g
0.2g
0.2g
L—谷氨酸
2.5g
4.2g
5.7g
甘氨酸
3.5g
5.9g
7.9g
L—组氨酸
3.0g
5.0g
6.8g
L—异亮氨酸
2.5g
4.2g
5.7g
L—亮氨酸
3.4g
5.9g
7.9g
【用法用量】
1.成人根据病人的需要，每24小时可输入本品500～1000ml。每日最大剂量：5%为50ml/kg；8.5%为29ml/kg；11.4%为23ml/kg，约合0.4g氮/kg(体重)。一般剂量为0.15～0.2g(氮)/(kg·日)。
2.新生儿和儿童遵医嘱使用。
5%与8.5%本品可经中心静脉或周围静脉输注，11.4%的本品可经中心静脉输注，但与其他营养制剂混合使用也可经周围静脉输注。使用本品时输注速度应缓慢。一般5%本品1000ml的适宜输注时间为5～7小时，约每分钟35～50滴；8.5%或11.4%本品1000ml的适宜输注时间至少16小时，约每分钟15～20滴。
复合氨基酸注射液(18)说明书
【药品名称】
通用名：复合氨基酸注射液(18)
英文名：Compound Amino Acid Injection(18)
汉语拼音：Fu He An Ji Suan Zhu She Ye(18)
【成份】本品为复方制剂，其组分为每1000ml含：
5%
8.5%
11.4%
L—丙氨酸

盐酸金刚烷胺

盐酸金刚烷胺盐酸金刚烷胺盐酸金刚烷胺盐酸金刚烷胺(Amantadine Hydrochloride，8-38)为一种对称的三环状胺，可以抑制病毒穿入宿主细胞，并影响病毒的脱壳，抑制其繁殖，起治疗和预防病毒性感染作用。

2012年5月，国家食品药品监督管理局对含盐酸金刚烷胺的非处方药(OTC)的说明书进行修订。

目录基本资料功能主治用法用量药品鉴别注意事项生产企业修订说明书编辑本段基本资料药物名称: 盐酸金刚烷胺药物别名: 金刚胺，三环癸胺Adamantane，Amanta die英文名称: Amantadine Hydrochloride药物说明: 片剂或胶囊剂:100mg;糖浆剂:5ml盐酸金刚烷胺:5mg。

结构式分子式:C10H17N.HCl 分子量 : 187.71主要成分: 暂无类别: 抗震颤麻痹药、抗病毒药。

性状: 本品为白色结晶或结晶性粉末;无臭，味苦。

本品在水或乙醇中易溶，在氯仿中溶解。

编辑本段功能主治在临床上能有效地预防和治疗各种A型流感病毒的感染。

在流感流行期采用本品作预防药，保护率可达50%~79%，对已发病者，如在48h内给药，能有效地治疗由于A型流感病毒引起的呼吸道症状。

金刚烷胺的抗病毒谱较窄，主要用于亚洲A 型流感的预防，对B型流感病毒、风疹病毒、麻疹病毒、流行性腮腺炎病毒及单纯疱疹病毒感染均无效。

由于口服吸收后能通过血脑屏障，会引起中枢神经系统的毒副反应。

进入脑组织后可促进释放多巴胺，或延缓多巴胺的代谢而发挥抗震颤麻痹作用。

对震颤麻痹有明显疗效，缓解震颤、僵直效果好。

起效快用药后48小时作用明显，对多种炎症、败血症、病毒性肺炎等与抗生素合用退热作用好。

原发性震颤麻痹及脑炎后、脑动脉硬化的震颤麻痹综合征，预防和治疗流感A型病毒。

编辑本段用法用量口服，成人，震颤麻痹:100mg/次，2次/日，不超过200mg/日。

流感A病毒感染:200mg/日，1,2次/日。

儿童，1岁,9岁:每日4.4mg,8.8mg，1,2次/日;9岁,12岁，100mg,200mg/日。

十八胺124-30-1

4.2 最重要的症状和影响，急性的和滞后的
据我们所知，此化学，物理和毒性性质尚未经完整的研究。
4.3 及时的医疗处理和所需的特殊处理的说明和指示
无数据资料
5 消防措施
5.1 灭火介质
火灾特征无数据资料灭火方法及灭火剂用水雾，耐醇泡沫，干粉或二氧化碳灭火。
5.2 源于此物质或混合物的特别的危害
碳氧化物,氮氧化物
9 理化特性
9.1 基本的理化特性的信息
a) 外观与性状
形状 : 固体
颜色 : 白色
b) 气味
无数据资料
c) 气味临界值
无数据资料
d) pH值
11.4 在 20 °C
e) 熔点/凝固点
50 - 52 °C - lit.
f) 起始沸点和沸程
232 °C 在 43 hPa - lit.
g) 闪点
148 °C - 闭杯
化学品安全技术说明书
无数据资料皮肤腐蚀/刺激皮肤 - 家兔 - 刺激皮肤。 - 4 h - OECD测试导则404 严重眼损伤 / 眼刺激眼睛 - 家兔 - 可对眼睛造成严重损伤。 - 24 h - OECD测试导则405 呼吸道或皮肤过敏无数据资料生殖细胞诱变体外基因毒性 - Ames试验 - Salmonella typhimurium - 有或没有代谢活化作用 - 阴性致癌性此产品中没有大于或等于 0。1%含量的组分被 IARC鉴别为可能的或肯定的人类致癌物。生殖毒性无数据资料特异性靶器官系统毒性（一次接触）无数据资料特异性靶器官系统毒性（反复接触）无数据资料潜在的健康影响
对水生生物毒性极大并具有长期持续影响。
13 废弃处置
13.1 废物处理方法

十八胺

十八胺
Octadecylamine、stearylamine、1-aminooctadecane、1-octadecanamine
十八烷基胺、硬脂胺、油脂十八胺
CAS：124-30-1
分子式：CH3(CH2)16CH2NH2
分子量：269.51
凝固点：54-58 ℃
熔点：52.86℃
沸点：232℃（4.27kPa）
凝固点：54-58 ℃
密度：0.8618g/cm3（20℃）
折射率：1.4522
闪点：149℃
白色蜡状结晶，极易溶于氯仿，溶于醇、醚、苯，微溶于丙酮，不溶于水，具有胺的通性，由硬脂酸氨化、加氢而得。

主要用于制十八烷季铵盐及多种助剂，如阳离子润滑脂稠化剂、矿物浮选剂、沥青乳化剂、抗静电剂、水处理用缓蚀剂、表面活性剂、杀菌剂、彩色胶片的成色剂等。

1.热力系统中的应用
十八胺又称薄膜胺，常温下为膜状固体，分解温度450℃以上，加入热力系统后高温下气化，气态十八胺随蒸汽进入锅炉、汽机及整个热力系统，在金属表面形成一层憎水性保护膜，将空气与金属隔绝，从而防止水及大气中的O2、CO2对金属的腐蚀。

2.浮选中的应用
十八胺在浮选中作为阳离子捕收剂，同时也具有一定的起泡效果。

十八胺在作为浮选剂使用时，由于其不溶于水，使得很多初次接触浮选的人不知如何使用，使用方法有二种：一是用稀盐酸将其制成盐再使用，二是将其在水中煮沸，并趁热加入浮选机进行浮选。

1。

表面活性剂——十八胺1

Size-and Shape-Controlled Synthesis of Bismuth NanoparticlesFudong Wang,§,‡Rui Tang,§,‡Heng Yu,§,†Patrick C.Gibbons,#,‡and William E.Buhro*,§,‡Department of Chemistry and Physics and Center for Materials Inno V ation,Washington Uni V ersity,Saint Louis,Missouri 63130-4899Recei V ed February 13,2008.Re V ised Manuscript Recei V ed April 2,2008Near-monodisperse Bi dots in the diameter range of 3-115nm are synthesized by a simple,solution-based one-step approach by varying the amounts of Bi[N(SiMe 3)2]3,Na[N(SiMe 3)2],and a polymer surfactant,poly(1-hexadecene)0.67-co-(1-vinylpyrrolidinone)0.33,employed.The reaction conditions are further modiﬁed to produce Bi nanorods and nanoplates.Alternatively,near-monodisperse Bi dots in the diameter range of 30-45nm are synthesized by a secondary-addition technique.With a slight modiﬁcation of this technique,nanoribbons are obtained.The roles of polymer and Na[N(SiMe 3)2]in the size and shape control of these Bi nanoparticles are discussed.IntroductionMetal nanoparticles are of great interest due to their unique size-and shape-dependent optical,1–4magnetic,5–8and catalyticproperties,9–11andpotentialapplicationsinbiosensing,12,13information storage,5,8catalysis,9–11and surface-enhanced Raman scattering (SERS).14,15Despite the extensive research activities and enormous progress in this ﬁeld,the main challenges have been and remain size and morphology control,and the lack of sufﬁcient mechanistic understanding to achieve this control.10,16–18Here we describe synthetic procedures for preparation of size-controlled,spherical Binanoparticles (dots),and strategies for generating rod-,plate-,and ribbon-shaped Bi nanoparticles.This study may also provide a basis for gaining mechanistic insights into size and shape control of metal nanoparticles.We chose to study the Bi system for two reasons.First and most importantly,Bi dots are the best catalysts for the solution-liquid -solid (SLS)growth of diameter-controlled semiconductor quantum wires and rods.19–24We now use such Bi nanoparticles almost exclusively for the SLS growth of semiconductor nanowires and expect that they will be generally useful to others.The motivation for this study,therefore,is to provide a diameter-controlled synthesis of near-monodispersed Bi dots over a wide diameter range,for SLS growth of near-monodispersed (in diameter)semicon-ductor nanowires over a similarly wide diameter range.Others are also interested in the electronic properties of Bi nanoparticles.Bulk Bi is a semimetal with unusual electronic properties (i.e.,magnetoresistance,thermoelec-tronic characteristics)due to its highly anisotropic Fermi surface,low carrier densities (105times smaller than conventional metals at 4.2K),small carrier effective masses,and long carrier mean free path (as long as a millimeter at 4.2K).25–28The electronic properties of Bi are highly susceptible to size-induced quantum conﬁnement effects.For*To whom correspondence should be addressed.E-mail:buhro@.§Department of Chemistry,Washington University.‡Center for Materials Innovation,Washington University.†Current address:MagArray,Inc.,450El Escarpado,Stanford,CA 94305-8431.#Department of Physics,Washington University.(1)El-Sayed,M.A.Acc.Chem.Res.2001,34,257–264.(2)Mock,J.J.;Barbic,M.;Smith,D.R.;Schultz,D.A.;Schultz,S.J.Chem.Phys.2002,116,6755–6759.(3)Kelly,K.L.;Coronado,E.;Zhao,L.L.;Schatz,G.C.J.Phys.Chem.B 2003,107,668–677.(4)Jin,R.;Cao,Y.C.;Hao,E.;Metraux,G.S.;Schatz,G.C.;Mirkin,C.A.Nature 2003,425,487–490.(5)Sun,S.;Murry,C.B.;Weller,D.;Folks,L.;Moser,A.Science 2000,287,1989–1992.(6)Sun,S.;Fullerton,E.E.;Weller,D.;Murry,C.B.IEEE Trans.Magn.2001,37,1239–1243.(7)Puntes,V.;Krishnan,K.M.;Alivisatos,A.P.Science 2001,291,2115–2117.(8)Dumestre,F.;Chaudret,B.;Amiens,C.;Renaud,P.;Fejes,P.Science2004,303,821–823.(9)Narayanan,R.;.;El-Sayed,M.A.J.Phys.Chem.B 2005,109,12663–12676.(10)Habas,S.E.;Lee,H.;Radmilovic,V.;Somorjai,G.A.;Yang,P.Nat.Mater.2007,6,692–697.(11)Xiong,Y.;Wiley,B.J.;Xia,Y.Angew.Chem.,Int.Ed.2007,46,7157–7159.(12)Nicewarner-Pena,S.;Freeman,R.G.;Reiss,B.D.;He,L.;Pena,D.J.;Walton,I.D.;Cromer,R.;Keating,C.D.;Natan,M.J.Science 2001,294,137–141.(13)Cao,Y.C.;Jin,R.;Mirkin,C.A.Science 2002,297,1536–1540.(14)Nie,S.M.;Emory,S.R.Science 1997,275,1102–1106.(15)Tessier,P.M.;Velev,O.D.;Kalambur,A.T.;Rabolt,J.F.;Lenhoff,A.M.;Kaler,E.W.J.Am.Chem.Soc.2000,122,554–9555.(16)Sun,Y.;Xia,Y.Science 2002,298,2176–2179.(17)Lisiecki,I.J.Phys.Chem.B 2005,109,12231–12244.(18)Murphy,C.J.;Gole,A.M.;Hunyadi,S.E.;Orendorff,C.J.Inorg.Chem.2006,45,7544–7554.(19)Yu,H.;Li,J.;Loomis,R.A.;Gibbons,O.C.;Wang,L.-W.;Buhro,W.E.J.Am.Chem.Soc.2003,125,16168–16169.(20)Wang,F.;Dong,A.;Sun,J.;Tang,R.;Yu,H.;Buhro,W.E.Inorg.Chem.2006,45,7511–7521.(21)Dong,A.;Wang,F.;Daulton,T.L.;Buhro,W.E.Nano Lett.2007,7,1308–1313.(22)Dong,A.;Tang,R.;Buhro,W.E.J.Am.Chem.Soc.2007,129,12254–12262.(23)Wang,F.;Yu,H.;Li,J.;Hang,Q.;Zemlyanov,D.;Gibbons,P.C.;Wang,L.-W.;Janes,D.B.;Buhro,W.E.J.Am.Chem.Soc.2007,129,14327–14335.(24)Wang,F.;Buhro,W.E.J.Am.Chem.Soc.2007,129,14381–14387.(25)Liu,K.;Chien,C.L.Phys.Re V .B 1998,58,681–684.(26)Heremans,J.;Thrush,C.M.;Zhang,Z.;Sun,X.;Dresselhaus,M.S.;Ying,J.Y.;Morelli,D.T.Phys.Re V .B 1998,58,91–95.(27)Heremans,J.;Thrush,C.M.;Lin,Y.-M.;Chroin,S.;Zhang,Z.;Dresselhaus,M.S.;Mansﬁeld,J.F.Phys.Re V .B 2000,61,2921–2930.(28)Lin,Y.-M.;Sun,X.;Dresselhaus,M.S.Phys.Re V .B 2000,62,4610–4623.3656Chem.Mater.2008,20,3656–366210.1021/cm8004425CCC:$40.75 2008American Chemical SocietyPublished on Web 05/08/2008D o w n l o a d e d b y H U A Z H O N G N O R M A L U N I V o n O c t o b e r 30, 2009 | h t t p ://p u b s .a c s .o r g P u b l i c a t i o n D a t e (W e b ): M a y 8, 2008 | d o i : 10.1021/c m 8004425example,Bi undergoes a semimetal to semiconductor transi-tion in nanowires when the wire diameter is decreased to about 50nm.29Theoretical studies suggest that Bi nanowires may exhibit an enhanced thermoelectric ﬁgure of merit,ZT ,at 300K.28An even larger thermoelectric effect might be achieved under dimensionally more-restricted conditions such as in Bi dots and rods.28,30,31Xia and co-workers have reported the synthesis of mono-disperse Bi dots in the diameter range of 100-600nm,32which,however,is not in the generally useful range for the growth of semiconductor quantum wires and rods.19–24Foos and co-workers reported the synthesis of Bi dots with diameters in the range of 3-10nm but did not achieve monodispersity.33In a related study,Wang,Ren,and co-workers prepared Bi dots,nanocubes,nanoplates,and nanobelts (nanoribbons)but did not address size control.34We previously reported the preparation of near-monodis-persed Bi dots using a seeded-growth method,in which very small (d ≈1.5nm)Au nanoclusters served as heterogeneous nucleants for nanoparticle growth.35This method,however,was somewhat laborious and provided a limited size range (8.5nm <d <12.5nm).We subsequently discovered a convenient one-step synthesis of near-monodisperse Bi dots by using the thermal decomposition of Bi[N(SiMe 3)2]3in the presence of Na[N(SiMe 3)2]but did not develop diameter control for a wide range of diameters.36In the present study,we have modiﬁed this one-step method to afford Bi dots in the diameter range of 3-115nm,with standard deviations in the diameter distributions of 4-19%of the nanoparticle mean diameters.The Bi dots can be made on a large scale and stored for at least a few years under an inert atmosphere for use as needed.The diameters and diameter distributions of the Bi dots are highly dependent on the relative quantities of Bi[N-(SiMe 3)2]3,Na[N(SiMe 3)2],and a polymer stabilizer em-ployed.Under certain conditions,nanoribbons,nanorods,and hexagonal nanoplates are also generated.The possible roles of Na[N(SiMe 3)2]and the polymer stabilizer in the size and morphology control are discussed.We expect that such convenient,optimized syntheses of Bi dots will beneﬁt research in the ﬁeld of semiconductor quantum wires and may provide opportunities for studying the size-and shape-dependent electronic properties of Bi nanostructures.Experimental SectionMaterials.Bi[N(SiMe 3)2]3was prepared according to a literature method.37Na[N(SiMe 3)2](as a 1.0M THF solution)was obtainedfrom Aldrich packaged under N 2in Sure/Seal bottles.Poly(1-hexadecene)0.67-co-(1-vinylpyrrolidinone)0.33(also known as poly(1-vinylpyrrolidone)-graft-(1-hexadecene)by Aldrich)was used as received from Aldrich.The solvent 1,3-diisopropylbenzene (DIPB)was purchased from Aldrich,shaken with concentrated sulfuric acid to remove thiophene,neutralized with K 2CO 3,washed with water,and distilled over Na.36A 25wt %poly(1-hexadecene)0.67-co-(1-vinylpyrrolidinone)0.33solution in DIPB (polymer -DIPB solution)was dried over molecular sieves at least one week with frequent shaking prior to use.36Polymer -DIPB solutions with lower concentrations were prepared by diluting the 25wt %stock solution with DIPB.Other reagents were used as received.Synthesis of Bi Dots.All synthetic steps were conducted under dry,O 2-free N 2(g).The reaction conditions (i.e.,quantities of reagents,reaction temperature,and reaction time)for a variety of Bi dot diameters are recorded in Table 1.In a typical synthesis of 7.1nm diameter (standard deviation )(11%)Bi dots,Bi[N(SiMe 3)2]3(303mg,0.44mmol)and Na[N(SiMe 3)2](1608mg of 1.0THF solution,1.78mmol)were combined with the 25wt %polymer -DIPB solution (10g)in a Schlenk reaction tube to generate a pale-red solution.This solution was then inserted into a temperature-controlled oil bath at 180°C with stirring,whereupon the solution turned red then black very quickly (∼1-2min).The ﬁnal solution (after 17h)contained a deep black dispersion of Bi dots.The Bi dots were stored without isolation in the synthesis mixture under inert atmosphere and remained stable for a few years.For the subsequent use in the synthesis of semiconductor quantum wires and rods,the Bi dots were typically not isolated from the reaction mixture.Rather,the mixture was used as a stock solution.The Bi dots could precipitate from the solution but were readily redispersed upon gentle shaking.Synthesis of Bi Nanorods and Nanoplates.The nanorods and nanoplates were synthesized using the same procedure as above.The quantities of reagents and reaction conditions used are recorded in Table S1(Supporting Information).Synthesis of Bi Dots Using the Secondary-Addition Tech-nique.A mixture containing Bi[N(SiMe 3)2]3(105mg,0.15mmol),Na[N(SiMe 3)2](1023mg of 1.0M THF solution,1.13mmol),and 25wt %polymer solution (10g)was preheated at 210°C for 2h before the dropwise addition of a mixture of Bi[N(SiMe 3)2]3(200mg,0.29mmol)and the 25wt %polymer solution (2g)from a syringe.The addition was ﬁnished in 1h.Stirring at 210°C was continued for an additional 15h,resulting in the 32.1nm diameter (standard deviation )(6%)Bi dots.Similarly,for the synthesis of the 44.2nm diameter (standard deviation )(6%)Bi dots,a mixture containing Bi[N(SiMe 3)2]3(110mg,0.16mmol),Na[N(SiMe 3)2](205mg of 1.0M THF solution,0.23mmol),and 25wt %polymer solution (8g)was preheated at 210°C for 1h before the dropwise addition of a mixture of Bi[N(SiMe 3)2]3(200mg,0.29mmol),and the 25wt %polymer solution (4g)from a syringe.The addition was ﬁnished in 2.3h.Stirring at 210°C was continued for an additional 16h.Synthesis of Bi Nanoribbons.A mixture containing Bi[N-(SiMe 3)2]3(16mg,0.023mmol),Na[N(SiMe 3)2](203mg of 1.0M THF solution,0.22mmol)and 12.5wt %polymer solution (8g)was preheated at 210°C for 35min before the dropwise addition of a mixture of Bi[N(SiMe 3)2]3(336mg,0.49mmol)and the 12.5wt %polymer solution (4g)from a syringe.The addition was ﬁnished in 2.2h.Stirring at 210°C was continued for an additional 17h,resulting in a grayish black suspension.(29)Dresselhaus,M.S.;Lin,Y.-M.;Rabib,O.;Jorio,A.;Souza Filho,A.G.;Pimenta,M.A.;Saito,R.;Samsonidze,G.G.;Dresselhaus,G.Mater.Sci.Eng.,C 2003,23,129–140.(30)Hicks,L.D.;Dresselhaus,M.S.Phys.Re V .B 1993,47,16631–16634.(31)Heremans,J.S.;Thrush,C.M.;Morelli,D.T.;Wu,M.-C.Phys.Re V .Lett.2002,88,216801.(32)Wang,Y.;Xia,Y.Nano Lett.2004,4,2047–2050.(33)Foos,E.E.;Stroud,R.M.;Berry,A.D.;Snow,A.W.;Armistead,J.P.J.Am.Chem.Soc.2000,122,7114–7115.(34)Wang,W.Z.;Poudel,B.;Ma,Y.;Ren,Z.F.J.Phys.Chem.B 2006,110,25702–25706.(35)Yu,H.;Gibbons,P.C.;Kelton,K.F.;Buhro,W.E.J.Am.Chem.Soc.2001,123,9198–9199.(36)Yu,H.;Gibbons,P.C.;Buhro,W.E.J.Mater.Chem.2004,14,595–602.(37)Carmalt,C.J.;Compton,N.A.;Errington,N.J.;Fisher,G.A.;Moenandar,I.;Norman,N.C.Inorg.Synth.1996,31,98–101.3657Chem.Mater.,Vol.20,No.11,2008Bi Nanoparticles D o w n l o a d e d b y H U A Z H O N G N O R M A L U N I V o n O c t o b e r 30, 2009 | h t t p ://p u b s .a c s .o r g P u b l i c a t i o n D a t e (W e b ): M a y 8, 2008 | d o i : 10.1021/c m 8004425TEM Analysis.The isolation and puriﬁcation steps were conducted in the ambient atmosphere.The black Bi nanoparticles (dots,rods,plates,or ribbons)were isolated from the reaction mixture (0.2-0.5mL)by adding toluene (ca.1mL)and methanol (ca.3mL)to the mixture,followed by centrifugation of the mixture and decanting of the supernatant.The precipitate was puriﬁed by redispersion in a mixture of toluene (ca.1mL)and methanol (ca.3mL)upon sonication in a cleaning bath,followed by centrifugation and decanting the supernatant.After puriﬁcation the precipitate could be redispersed in pure toluene to form uniform black dispersions for TEM analysis.Carbon-coated copper grids were dipped in the toluene solution and then immediately taken out in air to evaporate the solvent.The TEM images were obtained using a JEOL 2000FX microscope operated at 200kV and a magniﬁcation of 500K ×.The particle sizes were measured using the Image Pro Express (version 4.5)software at the 2×zoom.Generally,300-500particles were used in the statistical analysis for each sample.Selected-area electron-diffraction (SAED)patterns were taken with a camera length of 120cm.X-ray Powder Diffraction (XRD).XRD patterns were obtained using a Rigaku Dmax A vertical powder diffractometer with Cu K R radiation ( )1.5418Å)and Materials Data Incorporated (MDI)automation and Jade software.ResultsSynthesis of Bi Dots (d )3-30nm).The Bi dots in the diameter range of 3-30nm are the most useful for growing semiconductor quantum wires and rods in the quantum-conﬁnement regime.19–24Bi dots in this range were synthe-sized by the thermal decomposition of Bi[N(SiMe 3)2]3in the 25wt %polymer -DIPB solution.The syntheses were conducted by adding Na[N(SiMe 3)2]in varying amounts to a constant amount of Bi[N(SiMe 3)2]3to tune the Bi nano-particle sizes.Representative TEM images are shown in Figure 1.The standard deviations in the Bi dot diameter distributions were 4-18%of the dot mean diameters and thus approached near monodispersity (see Figure S1for representative diameter-distribution histograms).The electron-diffraction and XRD patterns (Figure S2)established the rhombohedral crystal structure of the Bi dots,with the exception of smaller Bi dots (∼4-10nm)which exhibited the cubic crystal structure.The transition from the cubic to rhombohedral structure occurring within the range of 10-12nm may be a surface-pressure phenomenon.Cubic Bi is a high-pressure phase,38and the internal pressure exerted by a nanocrystal surface is known to increase with decreasing nanocrystal size.39,40As noted above,varying amounts of Na[N(SiMe 3)2](Figure 2)were added to Bi[N(SiMe 3)2]3to adjust the precursor ratio.The Bi dot mean diameter decreased with increasing amount of Na[N(SiMe 3)2]or increasing Na[N-(SiMe 3)2]/Bi[N(SiMe 3)2]3(molar)ratio,to a limiting size of 3-4nm.This size minimum was achieved at a Na[N-(SiMe 3)2]/Bi[N(SiMe 3)2]3ratio of ∼6under the reaction conditions employed.The dashed curve (Figure 2)shows that the Bi dot sizes were also dependent on the initial concentration of Bi[N(SiMe 3)2]3.(38)Schaufelberger,P.;Merx,H.;Contre,M.High Temp.High Press.1973,5,221–230.(39)Baldinozzi,G.;Simeone,D.;Gosset,D.;Dutheil,M.Phys.Re V .Lett.2003,90,216103.(40)Magomedov,M.N.Tech.Phys.Lett.2005,31,13–17.Figure 1.Representative TEM images of 3-30nm diameter Bi dots.Diameter ((one standard deviation in the diameter distribution expressed as a percentage of the mean diameter))(a)4.7nm ((15%);(b)7.1nm ((11%);(c)9.4nm ((8%);(d)15.1nm ((6%);(e)20.4nm ((5%);(f)25.2nm ((5%).Figure 2.Bi nanoparticle diameter as a function of Na[N(SiMe 3)2]/Bi[N(SiMe 3)2]3molar ratio at various temperatures.The solid lines refer to experiments using 0.44mmol of Bi[N(SiMe 3)2]3and the dashed line to one using 0.15mmol of Bi[N(SiMe 3)2]3.Additional ∼1-3nm diameter Bi dots were formed at the low Na[N(SiMe 3)2]/Bi[N(SiMe 3)2]3ratios (<2)at 160°C (not shown).3658Chem.Mater.,Vol.20,No.11,2008Wang et al.D o w n l o a d e d b y H U A Z H O N G N O R M A L U N I V o n O c t o b e r 30, 2009 | h t t p ://p u b s .a c s .o r g P u b l i c a t i o n D a t e (W e b ): M a y 8, 2008 | d o i : 10.1021/c m 8004425The Bi dot diameters were not signiﬁcantly inﬂuenced by the reaction temperature,in the range of 160-210°C.However,at the lowest growth temperature of 160°C and lowest Na[N(SiMe 3)2]/Bi[N(SiMe 3)2]3ratios (<2;points not shown in Figure 2),the average particle size was smaller than that obtained at higher temperatures,due to the coexistence of small Bi dots (1-3nm).Such low-temper-ature reaction conditions should be avoided for the synthesis of mondispersed Bi dots.Synthesis of Bi Dots (d )30-115nm).As shown above,varying the Na[N(SiMe 3)2]/Bi[N(SiMe 3)2]3ratio at a ﬁxed polymer concentration allowed diameter control in the range of 3-30nm.By reducing the polymer concentration to various degrees,Bi dots having diameters of up to 115nm were produced.Other Bi nanoparticle morphologies were also obtained at decreased polymer concentrations.The Bi dot diameter was increased from 20.4to 39.7nm (compare Figure 1e and Figure 3a)by lowering the polymer concentration from 25to 12.5wt %,while holding the amounts of Na[N(SiMe 3)2](0.22mmol)and Bi[N(SiMe 3)2]3(0.44mmol)constant.As the polymer concentration was further lowered to 2.5wt %and the amount of Na[N-(SiMe 3)2]was reduced to 0.017mmol,the dot diameter increased to 54.5nm (Figure 3b).The dot diameter reached 69.8nm when no Na[N(SiMe 3)2]was added (2.5wt %polymer solution).Under these conditions,the Bi dot diameter was varied from 68.8-115nm by varying the amount of Bi[N(SiMe 3)2]3employed (Figure 3c-f).The diameter distributions also varied signiﬁcantly and were quite narrow when the larger amounts of Bi[N(SiMe 3)2]3(g 0.6mmol)were used.By lowering the polymer concentrations even further to 0.25wt %(in the presence of 0.057mmol Na[N(SiMe 3)2]),the dot diameters could be increased to as large as 173nm,but good morphology control was not retained (Figure S3).Larger crystallites of various morphologies were produced along with the Bi dots.In the absence of polymer,bulk Bi was generated,36indicating that a threshold concentration of polymer is essential for the controlled growth of Bi dots.Alternatively,large Bi dots (diameter >30nm)were synthesized by secondary addition of Bi[N(SiMe 3)2]3,in a slow dropwise manner,to a solution containing a dispersion of smaller,preformed Bi dots.However,the timing of the secondary addition of Bi[N(SiMe 3)2]3was required to be while the smaller,seed dots were in a growth regime.Otherwise,polydispersed dots and/or other morphologies resulted (Figure S4).Secondary addition of Bi[N(SiMe 3)2]3while the seed dots were in the early,nucleation stage broadened the diameter distributions and in some cases generated nanoribbons.Secondary addition of Bi[N(SiMe 3)2]3after the seed dots ﬁnished growing broadened the diameter distributions.The synthesis of near-monodisperse 32.1and 44.2nm diameter Bi dots by secondary addition is shown in Figure 4;however,this method was found to be unreliably controlled and thus less synthetically useful than the one-step,large-dot syntheses above.Synthesis of Bi Nanorods,Hexagonal Nanoplates,and Nanoribbons.Rod-like and hexagonal-plate shapes were synthesized in 2.5-5.0wt %polymer solutions in the presence of a small amount of Na[N(SiMe 3)2](0.06-0.22mmol)(Figure 5).The rods were truncated hexagonal plates,having truncation at two opposing plate edges.As the amount of Na[N(SiMe 3)2]was decreased from 0.22to 0.06mmol,the rods changed sizes from ∼20×∼50nm (diameter ×length)to ∼50×∼80nm,and the hexagonal nanoplates changed in edge-to-edge lateral dimension from ∼50nm to ∼100nm.The percentage of plates increased from 40%to 60%and that of rods decreased from 30to 15%.The remainder of the sample consisted of dots (about 30%).The percentage of dots increased to ∼80%with asigniﬁcantFigure 3.Representative TEM images of 40-115nm diameter Bi dots.Diameter ((one standard deviation in the diameter distribution expressed as a percentage of the mean diameter))(a)39.7nm ((6%);(b)54.5nm ((5%);(c)68.8nm ((7%);(d)78.2nm ((4%);(e)91.2nm ((7%);and (f)114.7nm ((9%).Figure 4.Representative TEM images of Bi dots prepared by secondary addition (see text).Diameter ((1standard deviation in the diameter distribution expressed as a percentage of the mean diameter))(a)32.1nm ((6%);(b)44.2nm ((6%).3659Chem.Mater.,Vol.20,No.11,2008Bi Nanoparticles D o w n l o a d e d b y H U A Z H O N G N O R M A L U N I V o n O c t o b e r 30, 2009 | h t t p ://p u b s .a c s .o r g P u b l i c a t i o n D a t e (W e b ): M a y 8, 2008 | d o i : 10.1021/c m 8004425decrease in rods and plates when larger amounts of Bi[N-(SiMe 3)2]3were used without changing other rger amounts of Na[N(SiMe 3)2](i.e.,1.11mmol)generated polydisperse dots that tended to aggregate (Figure S5).The aggregation tendency presumably reﬂected reduced steric stabilization as a result of the decreased amount of polymer for surface passivation.In the presence of a smaller amount of Na[N(SiMe 3)2](i.e.,0.017mmol),Bi dots were formed (see above and Figure 3b).The representative XRD pattern (Figure S6)revealed the rhombohedral crystal structure of these rod-and plate-shaped particles.The SAED patterns (Figure 6a and b)established that the hexagonal plates were oriented with their plate faces perpendicular to the c -axis (the [001]direction)of the crystal structure.The rod faces (parallel to the ﬁeld of view)were similarly [001]oriented,establishing that the rods are not merely plates with their hexagonal faces rotated 90°from the ﬁeld of view.The long axis of the rods was oriented in the [110]direction.The Bi nanoribbons (Figure 7)were synthesized by modifying the secondary-addition technique mentioned above.The initial mixture contained a small amount of Bi[N-(SiMe 3)2]3(0.023mmol)and Na[N(SiMe 3)2](0.22mmol),in comparison to the relatively large amount of Bi[N-(SiMe 3)2]3(0.16mmol)and Na[N(SiMe 3)2](0.30mmol)used in the synthesis of the 44.2nm diameter dots.In addition,a lower-concentration polymer solution (12.5wt %,instead of 25wt %)was employed to increase the yield of nanoribbons by decreasing the yield of Bi dots.This mixture was preheated in the reaction temperature for a short period (0.5h)before the dropwise addition of a secondary mixture of Bi[N(SiMe 3)2]3(0.49mmol),Na[N(SiMe 3)2](0.37mmol),and the 12.5wt %polymer solution (4g).The nanoribbons fell into two categories:thin nanoribbons having widths in the range of ∼60-200nm,and thick nanoribbons having width ×thickness dimensions of less than ∼50×∼50nm.The thin ribbons were twistable (Figure 7b)and occasionally had steps on their edges (Figure 7c).The thick ribbons had triangular,hexagonal,or rectangular cross-sections (Figure 7d -f).These ribbons were generally longer than 10µm.The crystalline ribbons exhibited the rhombohedral crystal structure and grew in the [110]direction (Figure6c,d).Figure 5.Representative TEM images of Bi nanorods and hexagonal nanoplates synthesized using 0.44mmol of Bi[N(SiMe 3)2]3in a 2.5wt %polymer solution in the presence of small amount of Na[N(SiMe 3)2]:(a)0.22mmol,(b)0.11mmol,and (c)0.06mmol.Figure 6.Electron diffraction patterns of a Bi hexagonal nanoplate (a),nanorod (b),nanoribbon (c)viewed in the [001]zone,and nanoribbon (d)in the [221]zone.The observed diffraction spots were indexed,establishing that the plate plane was perpendicular to the [001]direction,and the rod and ribbon long axes were oriented in the [110]direction.Figure 7.Representative TEM images of Bi nanoribbons,synthesized by secondary addition of Bi[N(SiMe 3)2]3into a preheated mixture containing small amounts of Bi[N(SiMe 3)2]3and Na[N(SiMe 3)2],and a low-concentra-tion polymer solution (see text).Thin ribbons having rectangular cross-sections (b)or steps (c)are indicated by pink and green arrows,respectively.Insets (d -f)show the shapes of the cross-sections for thick ribbons as indicated by the red or blue arrows;in some cases the inset images were obtained after sample tilting,as indicated.The scale bars are 200nm for images b -f.3660Chem.Mater.,Vol.20,No.11,2008Wang et al.D o w n l o a d e d b y H U A Z H O N G N O R M A L U N I V o n O c t o b e r 30, 2009 | h t t p ://p u b s .a c s .o r g P u b l i c a t i o n D a t e (W e b ): M a y 8, 2008 | d o i : 10.1021/c m 8004425DiscussionAs clearly revealed by the results,the three important synthetic parameters in this work were the amounts of the Bi[N(SiMe 3)2]3and Na[N(SiMe 3)2],and the concentra-tion of the polymer (poly(1-hexadecene)0.67-co-(1-vi-nylpyrrolidinone)0.33)employed.The inﬂuence of these parameters is plotted in the synthesis-space diagram in Figure 8.This three-dimensional graph falls short of a complete morphological phase diagram,because much of the synthesis space was not explored.The graph is useful,however,for summarizing and analyzing the experiments performed.The top surface of the synthesis space (at high polymer concentration)contains a large area where near-monodis-persed dots formed.Within this area,the size of the dots is dependent on the amount of Na[N(SiMe 3)2]used,as indicated by the blue arrow in Figure 8.The blue line connecting a series of points on the top surface identiﬁes the synthetic conditions we recommend for the growth of dots in the size range of 3-30nm.Two orange triangles are also plotted on the top surface of Figure 8,representing the formation of wire-dot mixtures at high polymer concentrations and low Na[N(SiMe 3)2]/Bi[N(SiMe 3)2]3ratios.We suspect there may be a wire-formation area or volume lying along the upper-front-right edge of the synthesis space.Indeed,the black triangle near the orange triangles represents our previously published conditions for the synthesis of Bi wires.36However,we didnot investigate the wire-formation region systematically here,as our primary goal was the synthesis of near-monodispersed,diameter-controlled dots.A second region of near-monodispersed dot formation is found along the lower-front-right edge of the synthesis space at very low or zero amounts of Na[N(SiMe 3)2]and low polymer concentrations.Here dots with diameters in the range of 40-115nm were grown,along a line orthogonal to the blue line discussed above,and indicated by the red arrow in Figure 8.We now speculate about the roles of reagent quantities in controlling the dot-growth behavior depicted in Figure 8.The decrease in dot diameter with increasing amount of Na[N(SiMe 3)2](along the blue line)strongly suggests that Na[N(SiMe 3)2]promotes dot nucleation.Increasing numbers of dot nuclei are presumably formed as the amount of Na[N(SiMe 3)2]is increased,leading to a smaller mean dot diameter at a ﬁxed amount of Bi[N(SiMe 3)2]3.Such nucleation may be of a classical or nonclassical kind.We have evidence,not presented here,that nanoparticle growth occurs by an initial burst formation of a very large number of small,primary Bi nanocrystallites (d e 2nm),which subsequently undergo aggregation to set the number of viable,growing dots.This proposed,nonclassical,aggregative nucleation process,and the mechanism by which Na[N(SiMe 3)2]may serve as a nucleation promoter will be discussed in a subsequentmanuscript.Figure 8.Synthesis-space diagram for Bi nanoparticles,showing the dependence of particle size and morphology on the amounts of Bi[N(SiMe 3)2]3,Na[N(SiMe 3)2],and polymer employed.The blue arrow on the upper-right-rear edge shows the trend of increasing dot size (3-30nm)with decreasing amount of Na[N(SiMe 3)2]at a ﬁxed (25wt %)polymer concentration (170-210°C).The blue line on the top surface indicates the recommended synthetic conditions for Bi dots in the size range of 3-30nm.The red arrow on the lower-right edge shows the trend of increasing dot size (40-115nm)with increasing amount of Bi[N(SiMe 3)2]3at very low or zero amounts of Na[N(SiMe 3)2]and low polymer concentrations (200°C).Ribbons (pink pentagons)were obtained at 210°C,wires (orange and black 36triangles)at 210and 203°C,respectively,polydispersed dots (purple star)at 200°C,and plates and rods (green diamonds)at 200-210°C.The dashed lines and small points are the projections of the synthetic conditions (large points)to guide the eye.3661Chem.Mater.,Vol.20,No.11,2008Bi Nanoparticles D o w n l o a d e d b y H U A Z H O N G N O R M A L U N I V o n O c t o b e r 30, 2009 | h t t p ://p u b s .a c s .o r g P u b l i c a t i o n D a t e (W e b ): M a y 8, 2008 | d o i : 10.1021/c m 8004425。

十八胺方案

兰铝自备电厂#2机组热力设备停运保护方案批准：审核：编制：2009年6月15日#2机组热力设备停运保护方案1、前言火电3x300MW机组，锅炉为哈尔滨锅炉厂生产，蒸发量为1065 t/h；汽轮机为东方汽轮机厂生产;2、停用保护的目的热力发电机组不可避免地要处于停用检修和备用状态，在停用期间，如果不采取有效的保护措施，机组的水汽系统暴露在大气环境中，会产生大气腐蚀，其范围和强度超过机组在良好水汽质量条件下正常运行时的腐蚀；停用腐蚀极大地损坏了金属材料本身，并在金属表面广泛地留下面积较大的蚀坑和针状蚀孔，从而成为机组运行时产生局部腐蚀的源点。

停用腐蚀产物会增加机组启动的时间和排污量，也使炉管沉积率增大，促进和加剧锅炉的运行腐蚀，严重时导致炉管破裂。

发电厂热力设备停备用和检修期间的防锈蚀保护是保证机组安全高效运行所必须的。

我国电力系统也专门制定了“火力发电厂停（备）用热力设备防锈蚀导则”，众多方法不同程度地存在缺点和局限性，给此项工作的开展带来诸多困难，尤其是对大机组的过热器、再热器、汽轮机、凝结水系统和液态排渣炉的停（备）用保护，经过研究和实践，推荐使用效果良好的停用保护方法：药剂成膜保护法。

3、药剂成膜保护方法3.1保护原理停用保护药剂为十八胺，它与金属表面接触后，会很容易在金属表面上形成一层分子膜，把空气与金属隔绝，从而防止水及大气中氧、二氧化碳对金属的腐蚀，保护了金属，保护效果好。

十八胺的使用是在机组停运过程中，将其加入系统，它进入锅炉后，在高温下挥发进入蒸汽，从而布满整个锅炉、汽轮机及热力系统，在热力系统的所有设备、管道内形成一层增水性保护膜，起到保护作用。

十八胺同时可渗入垢层下面，对垢下金属表面亦具有保护作用。

本方法适用于各种机组的保护，特别适用于检修设备和长期停备用设备的保护。

十八胺保护后的机组在再次启动时，由于温度作用，形成的十八胺膜会很快分解为NH3、H2等气体并被排出系统，渗入垢下的十八胺分解产生的气体还会使某些浮垢脱落，从而降低沉积率。

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分子式: C18H39N
分子量: 269.51
中文名称：十八胺停炉保护剂、十八胺乳浊液
英文名称：Octadecylamine
性质描述：该产品是采用现代先进的物理溶制技术生产的锅炉停用防腐保护剂，它不含其它任何化学成分。

该产品性能稳定、使用方便不需加热、在纯水中分散性能好、长期存放不变质、不分层。

质量标准:
外观白色浆状液体
密度0.98~1.03g/cm3（20℃）
pH值7.8-8.2(1%水溶液)
含量≥10%
使用要求:
汽包压力＞7Mpa
主蒸汽压力420-470℃
药剂使用量：按水汽系统的水容量计算，药剂使用量为150-200mg/l （按有效成分计）；
使用效果：
（1）水汽系统内表面有良好的憎水性，水珠呈圆球状；
（2）酸性硫酸铜变红时间；大于20分钟（通常要求50秒即可）；（3）有效保护时间：6~12个月。

保护范围：整个汽水系统、包括除氧器、汽包、过热器、汽轮机等。

使用方法：在机组滑停时由专用加药装置加入除氧器出口即可。

将本品按1.5-2kg/吨水，加入炉内，稍加温或停炉时余热温度即可，投药后，各个阀门必须封闭严密。