丁秀萍1,2,王亚斌1,3,黄玉东3
(1.中国科学院盐湖资源综合高效利用重点实验室(中国科学院青海盐湖研究所),西宁 810008; 2.中国科学院青海盐湖研究所 盐湖化学分析测试中心,西宁 810008; 3.哈尔滨工业大学 化工与化学学院,哈尔滨 150001)
摘要:
为了得到高比表面且尺寸均一的纤维状二氧化硅纳米球, 采用静止和搅拌水热反应法制备了该类纳米粒子, 探讨了制备机理及影响生长的因素.以同反应条件下微波法制备所得纤维状二氧化硅纳米球为参比样品, 通过扫描电镜和透射电镜(SEM和TEM)观察了微波反应法和水热反应法所得3类纤维状二氧化硅纳米球的形貌和结构特征、傅里叶变换红外光谱(FT-IR)考察了纳米粒子的化学组成、X射线衍射谱(XRD)探究了纳米粒子的体相结构信息, 以及采用氮气吸附脱附手段揭示了纳米粒子的吸附脱附类型及孔径分布.结果表明：水热反应能够生成直径较大、形貌更为均匀的纳米球; 搅拌水热反应效果更明显, 产物尺寸更为均一; 3种反应方式合成的纳米球具有相似的化学结构和化学官能团, 都属于Ⅳ型吸附且滞后环属于H3型; 3类纳米球的比表面积(和孔体积)分别为480.156 m2 /g(1.287 cm3 /g)、464.757 m2 /g(0.654 cm3 /g)和429.351 m2 /g(0.726 cm3 /g).形貌和结构的差别归因于反应体系的压力和反应母液均匀程度, 前者促使生成均匀的微乳液, 后者促进生成均匀的反胶束.
关键词: 界面化学 介孔材料 二氧化硅纳米球 纤维状 乳液
DOI：10.11918/j.issn.03676234.201611111
分类号:O613.7
文献标识码:A
基金项目:国家自然基金面上项目(41573013)；中国科学院仪器功能开发项目(Y510171158)
Hydrothermal synthesis and characterization of fibrous silicananospheres
DING Xiuping1,2,WANG Yabin 1,3,HUANG Yudong3
(1.Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources(Qinghai Institute of Salt Lakes, Chinese Academy of Sciences), Xining 810008, China; 2.Salt Lake Chemistry Analysis and Test Center, Qinghai Institure of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China; 3.School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China)
Abstract:
To obtain high-specific-surface-area and uniform silica nanospheres of fibrous morphologies, the hydrothermal method with and without stirring was adopted to fabricate the nanoparticles, and the fabrication mechanism as well as the influencing factors on their development were explored. Taking fibrous silica nanospheres prepared by microwave method under the same condition as references, scanning electron microscope (SEM) and transmission electron microscope (TEM) were applied to observe morphologies of the silica nanospheres developed by hydrothermal and microwave methods, Fourier transform infrared spectroscopy (FT-IR) to identify chemical compositions of the three silica nanospheres, X-ray diffractometer (XRD) to reveal the crystal structures, as well as nitrogen (N2) adsorption-desorption isotherms to characterize the type of adsorption-desorption and pore diameters, respectively. The results indicate that nanospheres synthesized by hydrothermal method possess bigger sizes and more uniform morphologies. Especially, the effectiveness of hydrothermal method with stirring was more obvious. These three kinds of the as-prepared silica nanospheres own same chemical structures and chemical functional groups, and belong to Ⅳ adsorption-desorption isotherms with H3 loops. Specific surface area (and pore volumes) of the three nanospheres were 480.156 m2 /g(1.287 cm3 /g), 464.757 m2 /g(0.654 cm3 /g) and 429.351 m2 /g(0.726 cm3 /g), respectively. The pressure of the reaction system and the degree of uniformity of the reaction mother liquor collectively endow the nanospheres with special properties like morphologies and structural differences. The former accelerates uniform micellar emulsion, and the latter prompts formation of reverse micelles.
Key words: interface chemistry mesoporous material silica nanosphere fibrous morphology emulsion
丁秀萍, 王亚斌, 黄玉东. 纤维状二氧化硅纳米球的水热合成与表征[J]. 哈尔滨工业大学学报, 2018, 50(2): 116-121. DOI: 10.11918/j.issn.03676234.201611111.
DING Xiuping, WANG Yabin, HUANG Yudong. Hydrothermal synthesis and characterization of fibrous silicananospheres[J]. Journal of Harbin Institute of Technology, 2018, 50(2): 116-121. DOI: 10.11918/j.issn.03676234.201611111.
基金项目 国家自然基金面上项目(41573013);中国科学院仪器功能开发项目(Y510171158) 作者简介 丁秀萍(1982—), 女, 硕士, 工程师;
黄玉东(1965—), 男, 教授, 博士生导师, ****特聘教授 通信作者 王亚斌, ybw@yau.edu.cn; xbnlxbnlxbnl@126.com 文章历史 收稿日期: 2016-11-23
Contents -->Abstract Full text Figures/Tables PDF
纤维状二氧化硅纳米球的水热合成与表征
丁秀萍1,2, 王亚斌1,3
, 黄玉东3 1. 中国科学院盐湖资源综合高效利用重点实验室（中国科学院青海盐湖研究所），西宁 81008;
2. 中国科学院青海盐湖研究所 盐湖化学分析测试中心，西宁 81008;
3. 哈尔滨工业大学 化工与化学学院，哈尔滨 150001
收稿日期: 2016-11-23
基金项目: 国家自然基金面上项目(41573013);中国科学院仪器功能开发项目(Y510171158)
作者简介: 丁秀萍(1982—), 女, 硕士, 工程师;
黄玉东(1965—), 男, 教授, 博士生导师, ****特聘教授
通信作者: 王亚斌, ybw@yau.edu.cn; xbnlxbnlxbnl@126.com
摘要: 为了得到高比表面且尺寸均一的纤维状二氧化硅纳米球, 采用静止和搅拌水热反应法制备了该类纳米粒子, 探讨了制备机理及影响生长的因素.以同反应条件下微波法制备所得纤维状二氧化硅纳米球为参比样品, 通过扫描电镜和透射电镜(SEM和TEM)观察了微波反应法和水热反应法所得3类纤维状二氧化硅纳米球的形貌和结构特征、傅里叶变换红外光谱(FT-IR)考察了纳米粒子的化学组成、X射线衍射谱(XRD)探究了纳米粒子的体相结构信息, 以及采用氮气吸附脱附手段揭示了纳米粒子的吸附脱附类型及孔径分布.结果表明：水热反应能够生成直径较大、形貌更为均匀的纳米球; 搅拌水热反应效果更明显, 产物尺寸更为均一; 3种反应方式合成的纳米球具有相似的化学结构和化学官能团, 都属于Ⅳ型吸附且滞后环属于H3型; 3类纳米球的比表面积(和孔体积)分别为480.156 m2 /g(1.287 cm3 /g)、464.757 m2 /g(0.654 cm3 /g)和429.351 m2 /g(0.726 cm3 /g).形貌和结构的差别归因于反应体系的压力和反应母液均匀程度, 前者促使生成均匀的微乳液, 后者促进生成均匀的反胶束.
关键词: 界面化学 介孔材料 二氧化硅纳米球 纤维状 乳液
Hydrothermal synthesis and characterization of fibrous silicananospheres
DING Xiuping1,2, WANG Yabin1,3
, HUANG Yudong3 1. Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources(Qinghai Institute of Salt Lakes, Chinese Academy of Sciences), Xining 810008, China;
2. Salt Lake Chemistry Analysis and Test Center, Qinghai Institure of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China;
3. School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Abstract: To obtain high-specific-surface-area and uniform silica nanospheres of fibrous morphologies, the hydrothermal method with and without stirring was adopted to fabricate the nanoparticles, and the fabrication mechanism as well as the influencing factors on their development were explored. Taking fibrous silica nanospheres prepared by microwave method under the same condition as references, scanning electron microscope (SEM) and transmission electron microscope (TEM) were applied to observe morphologies of the silica nanospheres developed by hydrothermal and microwave methods, Fourier transform infrared spectroscopy (FT-IR) to identify chemical compositions of the three silica nanospheres, X-ray diffractometer (XRD) to reveal the crystal structures, as well as nitrogen (N2) adsorption-desorption isotherms to characterize the type of adsorption-desorption and pore diameters, respectively. The results indicate that nanospheres synthesized by hydrothermal method possess bigger sizes and more uniform morphologies. Especially, the effectiveness of hydrothermal method with stirring was more obvious. These three kinds of the as-prepared silica nanospheres own same chemical structures and chemical functional groups, and belong to Ⅳ adsorption-desorption isotherms with H3 loops. Specific surface area (and pore volumes) of the three nanospheres were 480.156 m2 /g(1.287 cm3 /g), 464.757 m2 /g(0.654 cm3 /g) and 429.351 m2 /g(0.726 cm3 /g), respectively. The pressure of the reaction system and the degree of uniformity of the reaction mother liquor collectively endow the nanospheres with special properties like morphologies and structural differences. The former accelerates uniform micellar emulsion, and the latter prompts formation of reverse micelles.
Key words: interface chemistry mesoporous material silica nanosphere fibrous morphology emulsion
有序介孔材料作为新型纳米结构材料诞生于上世纪90年代, 并迅速得到物理学、化学与材料学界的重视, 逐步发展成为研究热点.有序介孔二氧化硅材料成功合成于1970年, 其比表面高、介孔结构有序、生物兼容性良好、表面性能可调控.上述特性使得介孔二氧化硅材料能够应用在催化、光学活性材料和生物材料领域.自从有序介孔二氧化硅MCM-41发现以来, 不同形貌、孔型以及结构的介孔二氧化硅材料相继成功制备.
2010年, Polshettiwar等[1]首次成功合成纤维状介孔二氧化硅球(KCC-1[2]), 该类材料迅速吸引了科研工作者的关注.纤维状二氧化硅球因其中心放射褶皱结构[3], 从而具有更高的比表面积和更具层次性的孔道[4].以KCC-1为催化剂载体, 进一步研究了负载不同催化剂的复合纳米粒子的催化性能[5-9].例如, 将氢化钽负载在纤维状二氧化硅上(TaH/KCC-1), 产物能够更稳定且能够进行更高活性催化烯烃的氢置换反应[5].担载贵金属钯后, 复合催化剂(Pd/KCC-1)能够加速芳香卤化物的Suzuki偶联反应并得到高产率产物[6].Singh等[10]利用原子沉积技术, 将二氧化钛(TiO2)沉积在KCC-1表面, 得到相对于将TiO2沉积在MCM-41和SBA-15表面活性更高的复合催化剂.此外, 文献[1]将不同类型和个数的氨基官能团嫁接在KCC-1表面, 对二氧化碳(CO2)进行吸附捕捉[11-12].结果表明：该类吸附剂较MCM-41和SBA-15有更好的吸附容量, 原因在于其具有较大的表面积和孔道体积.国外Sadeghzadeh等[13]也开展了以KCC-1为载体的催化研究, 国内一些课题组也进行了相关探索.例如, Dong等[14-20]以KCC-1为载体, 制备了多种复合催化剂, 取得了系列进展.Sun等[21-22]在KCC-1表面嫁接喹啉官能团和B官能团, 成功制备锌离子和汞离子的感应探针.以KCC-1为模板剂, 合成了具有纤维状结构的多级碳中空微球和氮化碳(C3N4)纳米粒子, 前者用来制备高性能超级电容器电极[23], 后者用来制备能够加速电荷收集和分离的催化剂[24].
尽管功能化的纤维状形貌介孔二氧化硅球在催化、CO2捕捉、金属离子感应探针以及蛋白质释放[2, 25]方面取得了一些进展, 但还存在两个基本问题：1)KCC-1合成机理存在多种观点, 尚待完善.2)目前制备的KCC-1都存在尺寸不均匀现象.多数研究致力于反应条件的调控和反应机制的探讨[3-4, 26-27], 极少涉及探讨KCC-1尺寸问题[4, 22-23, 27].文献[1]首次使用微波反应器合成KCC-1时.而在后续工作中, 采用水热反应釜作为反应容器.水热反应釜相对于微波反应器价格便宜, 实验室容易配置.然而, 没有相关研究对比微波反应和水热反应制备KCC-1并研究形貌和孔道结构特征.更没有深入研究探讨水热反应过程中, 搅拌对KCC-1形貌和孔道结构影响(微波反应合成KCC-1时, 反应容器水平转动, 可视为无搅拌).因此, 本文以合成均匀尺寸KCC-1为目的, 探讨微波反应、静止水热反应和搅拌水热反应对KCC-1形貌和孔道结构的影响.
1 实验 1.1 材料与设备硅酸四乙酯、环己烷、戊醇、溴代十六烷基吡啶和尿素均购自国药集团化学试剂有限公司, 试剂纯度均为分析纯.微波合成在多通量微波消解系统(JUPITFER-B, 上海新仪微波化学科技有限公司)进行.水热合成在均相反应器(JX-8-200, 烟台松岭化工设备有限公司)进行, 静置反应或保持搅拌速度为60 r/min.
1.2 方法KCC-1的微波合成和水热合成：将2.5 g硅酸四乙酯溶于30 mL的环己烷与1.5 mL的戊醇混合液, 充分搅拌形成溶液A.将1 g溴代十六烷基吡啶与0.6 g尿素溶液30 mL去离子水, 充分搅拌形成溶液B.将B溶液加入A溶液, 充分搅拌形成反应液.将上述反应液置入聚四氟乙烯密封反应器, 在微波反应器(保持功率400 W)和水热反应釜(搅拌与不搅拌, 搅拌速度为60 r/min)中进行合成, 120 ℃反应4 h.反应结束后, 离心分离产物, 去离子水和丙酮各洗涤3次, 空气中干燥24 h.将所得不同产物在550℃煅烧6 h去除模板剂, 得到3种不同反应条件下的产物, 即微波反应产物(M-KCC-1, M代表微波microwave), 静止水热反应产物(H-KCC-1, H代表水热hydrothermal)和搅拌水热反应产物(HS-KCC-1, S代表搅拌stirring).
1.3 结果表征采用日本HITACHI-SU8010型场发射扫描电子显微镜(field emission scanning electron microscopy, FESEM)和日本JEM2011型透射电子显微镜(transmission electron microscopy, TEM)观察样品的微观形貌; 采用荷兰PANalytical X’Pert PRO X射线衍射仪(Cu靶, Kα射线, λ=0.154 2 nm)表征样品的晶体结构.采用美国热电公司的傅里叶变换红外光谱(nexus)收集并分析产物化学官能团信息.产物的孔径和比表面积测定则在美国康塔仪器公司的Autosorb-iQ2-MP下进行.
2 结果与分析 2.1 SEM及TEM分析图 1为微波反应产物M-KCC-1, 静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的SEM形貌图以及粒径分布曲线.整体而言, 3种反应方式都能制备纤维状形貌介孔二氧化硅球, 但是所得纳米颗粒尺寸大小差异巨大.微波反应产物M-KCC-1尺寸极不均一(如图 1(a)所示), 颗粒直径分布在100~500 nm之间, 大部分纳米粒子(约45%)尺寸集中在350~400 nm.静止水热反应产物H-KCC-1粒子尺寸相对增大(如图 1(b)所示), 颗粒直径分布在200~900 nm之间, 大部分纳米粒子(约75%)尺寸集中在700~900 nm且以尺寸为700 nm颗粒为主.而以60 r/min进行搅拌水热反应时, 所得产物HS-KCC-1颗粒直径分布在500~900 nm之间(破裂纳米颗粒不列入统计).大部分纳米粒子(约80%)尺寸集中在790~850 nm之间, 且以尺寸为800 nm颗粒为主(如图 1(c)所示).综上可知, 微波反应制备的纤维状介孔二氧化硅纳米球直径较小, 尺寸大小极不均匀.水热反应能够生成直径较大、形貌较为均匀的纤维状介孔二氧化硅纳米球.对水热反应进行搅拌, 产物尺寸更为均一.对上述3种产物进行透射电镜分析, 结果如图 2所示.M-KCC-1.H-KCC-1和HS-KCC-1都具有均匀的放射状孔道, 呈纤维状发散型形貌.微波条件下反应产物孔道壁较厚, 孔道较大; 水热反应条件下产物孔道壁较薄, 孔道较小, 很容易观测到两者区别.
Figure 1
图 1 微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的扫描电镜图以及粒径分布曲线 Figure 1 SEM images and diameter distribution curves of M-KCC-1 synthesized by microwave reaction, H-KCC-1 developed by hydrothermal method without stirring, and HS-KCC-1 yielded by hydrothermal method with stirring Figure 2
图 2 微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的透射电镜图 Figure 2 TEM images of M-KCC-1 synthesized by microwave reaction, H-KCC-1 developed by hydrothermal method without stirring, and HS-KCC-1 yielded by hydrothermal method with stirring 2.2 FT-IR及XRD分析图 3为微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的红外吸收特征谱图.810 cm-1吸收峰归因于Si—O的对称伸缩振动[21], 963 cm-1为Si—OH的振动吸收峰[17].Si—O—Si的振动吸收峰出现在1 090 cm-1, H2O的吸收振动峰出现在1 645 cm-1[13, 17, 21].3 430 cm-1为典型的—OH吸收峰, 可知来自于KCC-1表面Si—OH和吸附的水分子.图 4为微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的X射线衍射特征谱图.3类产物都在2θ介于15°~30°之间有特征峰, 且以22°处为中心, 该特征信号归功于无定形二氧化硅[13, 17, 28].由上述结果可知, 3种反应方式合成的纤维状形貌介孔二氧化硅球具有相似的化学结构和化学官能团.
Figure 3
图 3 微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的傅里叶变换红外光谱图 Figure 3 FT-IR spectra of M-KCC-1 synthesized by microwave reaction, H-KCC-1 developed by hydrothermal method without stirring, and HS-KCC-1 yielded by hydrothermal method with stirring Figure 4
图 4 微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的X射线粉末衍射 Figure 4 XRD spectra of M-KCC-1 synthesized by microwave reaction, H-KCC-1 developed by hydrothermal method without stirring, and HS-KCC-1 yielded by hydrothermal method with stirring 2.3 氮气吸附脱附分析图 5显示微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的氮气吸附脱附曲线, 都属于典型的Ⅳ型吸附脱附等温线.尽管研究KCC-1的课题组都确定该类介孔材料遵循Ⅳ型吸附脱附等温线, 但是对其滞后环类型都存在各自看法.Gai等[29]与Yu等[30]认为滞后环属于H1型, 而Suendo则归功于H1型或H3型.众所周知, H1型属于两端开口的管径分布均匀的圆筒状孔, 而H3型属于平板狭缝结构、裂缝和楔形结构等.为了从形貌上直接得出KCC-1滞后环的类型, 对3种反应产物进行电镜观察, 有幸于HS-KCC-1中发现破裂的半球(如图 5中插图所示).由图 5可以直接观察到HS-KCC-1存在片状粒子堆积的狭缝孔, 滞后环属于H3型, 本文首次由电镜结果确定KCC-1滞后环类型.
Figure 5
注：M-KCC-1和HS-KCC-1相对H-KCC-1分别上移50 cm3/g和下移50 cm3/g.图 5 微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的氮气吸附脱附等温线 Figure 5 Nitrogen adsorption-desorption isotherms of M-KCC-1 synthesized by microwave reaction, H-KCC-1 developed by hydrothermal method without stirring, and HS-KCC-1 yielded by hydrothermal method with stirring 图 6为微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的孔径分布图.由图 6可知, M-KCC-1的放射状孔径集中在1.4、3.4 nm, 并在5.0、8.0、10.9、13.3 nm处有少量分布.不难理解, M-KCC-1粒径大小差别巨大(如图 1(a)所示), 导致生成不同宽窄的纤维状通道.H-KCC-1和HS-KCC-1的放射状孔径集中在1.4、3.4 nm, 并在5.0 nm处有少量分布.如图 1(c)所示可知HS-KCC-1粒径均匀, 但是孔径分布在3个纳米尺度上.说明纤维状孔道非均匀存在, 进一步和KCC-1滞后环属于H3类型相对应.3种KCC-1粒子的比表面积(和孔体积)分别为480.156 m2/g(1.287 cm3/g)、464.757 m2/g(0.654 cm3/g)和429.351 m2/g(0.726 cm3/g).
Figure 6
注：H-KCC-1和HS-KCC-1相对M-KCC-1分别上移0.03 cm3/(g·nm)、0.06 cm3/(g·nm).图 6 微波反应产物M-KCC-1、静止水热反应产物H-KCC-1和搅拌水热反应产物HS-KCC-1的孔径分布 Figure 6 Pore diameter distributions of M-KCC-1 synthesized by microwave reaction, H-KCC-1 developed by hydrothermal method without stirring, and HS-KCC-1 yielded by hydrothermal method with stirring 2.4 机理分析综上所述, 微波法、静止水热反应法和搅拌水热反应方式都能制备纤维状形貌介孔二氧化硅球, 产物化学组成相同.但是, 所得纳米颗粒尺寸和孔道结构大小差异很大.对比微波反应法和水热反应法, 有两种明显的反应条件差异.1)反应压力变化不同.微波反应釜压力在反应的最初1 h, 随后2 h和最后1 h, 分别为1.1、1.0、0.8 MPa.不论静止或搅拌与否, 水热反应釜压力在120 ℃恒定.2)搅拌影响.虽然微波反应过程, 密封反应釜水平转动, 但是不能使得已经分层的微乳液变为一体的混合溶液.水热反应釜在容器内以60 r/min颠倒旋转, 使得分层的微乳液变为一体的混合溶液.通过控制上述两个反应条件, 可以得到尺寸较大且均匀的纤维状形貌二氧化硅纳米球.文献[3]研究了KCC-1的形成机理, 表明该类纳米粒子在Winsor Ⅲ型双连续微乳液中形成.指出表面活性剂包裹的水油界面能够形成封闭的球状结构, 形成胶束乳液, 进而成为纳米粒子生长的种子位点.不难推测, 反应溶液恒定的外部压力能够生成均一的球状结构, 从而得到尺寸大小近似一致的纤维状纳米颗粒.变化的压力影响溶液内部应力, 使得胶束形成过程受力不同, 从而导致纤维状二氧化硅纳米球尺寸不均匀.Febriyanti等[26]揭示KCC-1的形成机理为：该类纳米粒子由初始混合反应溶液中的反胶束引发, 硅酸四乙酯水解产物渗入胶束, 脱水缩合而成.由此可知, 搅拌能够使混合反应溶液均匀, 生成统一的反胶束, 从而得到尺寸近似相同的纳米颗粒.本文采用的搅拌速度为60 r/min, 后续的工作可以集中讨论不同搅拌速度对KCC-1形貌影响(水热反应釜).此外, 可以得出反应体系环境压力对纳米颗粒均匀程度的影响大于外部搅拌作用.
3 结论1) 静止和搅拌水热反应均可成功制备具有高比表面的纤维状二氧化硅纳米球, 与同条件下的微波反应产物具有相似的化学组成和化学结构.
2) 水热反应产物更加均匀、粒径更大、孔道壁相对较薄、孔径较窄.搅拌的水热反应产物这一特点更为明显, 因为搅拌水热反应能够保持恒定的反应压力和均匀的溶液组成.恒压促进生成均一的胶束乳液, 均匀溶液促使生成均匀的反胶束.
3) 本实验采用的水热反应技术工艺简单, 设备成本低廉(相对微波反应条件)、重复性好(已进行10次实验), 可实现大规模生产具有高比表面的纤维状二氧化硅纳米球.
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