Name: highly stable, functional hairy nanoparticles and biopolymers from wood fibers: towards sustainable nanotechnology
Uploaded: 2016-07-20T14:00:00.000+00:00
Duration: 11 min 32 s
Description: Watch this Scientific Journal Video about Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology at JoVE.com

Financial support from an Industrial Research Chair funded by FPInnovations and NSERC for a NSERC Discovery grant and from the NSERC Innovative Green Wood Fiber Products Network are acknowledged.

小心:触摸它们之前，请阅读所有化学品的材料安全数据表（MSDS）。许多在此工作中使用的化学品可能会导致严重的健康损害。使用个人防护，如实验室外套，手套和护目镜是必须的。不要忘记，安全是第一位的。在整个合成中使用的水是蒸馏水。 1.部分氧化纤维作为中间体的制备<ol><li>撕4克C-90软木纸浆片材切成小块的约2×2 平方厘米。 </li><li>浸泡撕裂纸浆片在水中至少一天。 </li><li>崩解使用机械粉碎机以实现几乎均匀分散的湿的纸浆。 </li><li>为了组装真空过滤，在布氏漏斗中确保一个尼龙过滤器，并放置在漏斗中的过滤器烧瓶中。然后，过滤器烧瓶连接到使用适当的管道真空泵。打开泵，并倒在funn崩解的纸浆解决方案埃尔到纸浆从液体中分离出来。 </li><li>测量湿纸浆（M 1）的重量，并计算出由纸浆的吸水量:M W，1 = M 1 - 4。 </li><li>高碘酸盐氧化剂溶液的制备<ol><li>对于SNCC / DAMC合成:分别在200- 男女，加入1ml水溶解2.64克高碘酸钠（的NaIO 4）和15.48氯化物克氯化钠（NaCl）。 </li><li>对于ENCC / DCC合成:分别在266- 男女，加入1ml水溶解5.33克高碘酸钠（的NaIO 4）和15.6氯化克氯化钠（NaCl）。 </li></ol></li><li>分别加入湿纸浆1.6准备的解决方案。确保的水的总量（由纸浆加加入水吸收）是等于200毫升SNCC和266毫升ENCC合成。 </li><li>覆盖烧杯用铝箔彻底防止高碘失活在RT以速度〜105转搅拌t的所需量，同时IME根据表1，实现了有利的醛含量。作为一个例子，以获得〜6.5毫摩尔/克醛，为96小时反应。 </li><li>当反应时间过去后，打开铝箔和（在ENCC / DCC合成的情况下）乙二醇加入1毫升（在SNCC / DAMC合成的情况下）或3 ml至该混合物并搅拌10分钟以终止氧化经淬火碘酸反应。 </li><li>收集通过真空过滤（根据1.4）的氧化纸浆，再分散它在500毫升水中，并搅拌它30分钟。重复此步骤，至少5次，以从高碘彻底清洁纸浆。 </li><li>在氧化的纸浆中的第 5 次水洗涤之后，纸浆从溶液通过真空过滤分离，将其存储在冷的（4℃）的地方。 </li></ol> 2. SNCC和DAMC的合成<ol><li>划分部分氧化的湿纸浆（M 1），在1.11得到，由四个:M 2 = M 1/4，并测量吸收水的重量:M W，2 = M 2 - 1。 </li><li>分散在纸浆（100 - 男女，2）克水在圆底烧瓶（总水含量= 100克）。 </li><li>放置在油浴中的圆底烧瓶中并加热，在80℃下的部分氧化的纸浆为6小时，同时轻轻地搅拌。 注意:如果纸浆被完全用高碘氧化（DS = 2）， 例如 ，通过在含有3.87克氯化钠（8.64毫摩尔）和65毫升的水，同时搅拌6的溶液1克纸浆1.85克的NaIO 4（8.65毫摩尔）反应天，这取决于水的加热条件和停留时间，二醛纤维素（DAC）的特性改变（ 表2）。 </li><li>冷却该溶液至室温。 </li><li>离心18,500 XG溶液10分钟。沉淀物是unfibrillated纤维素（级分1）。 </li><li>仔细分离上清液并称重（A）。 </li><li>加入1.7（A）G丙醇到，同时搅拌以沉淀SNCC在2.6得到的上清液。关于分离SNCC并添加丙醇细节是图1中可用。 </li><li>离心在3000 xg离心双相溶液10分钟，并分离所得凝胶状沉淀物（第二级分，SNCC）通过倾析，这是准备再分散和透析用于进一步纯化（部分4）和表征（部分5）。 </li><li>在2.8中得到的上清，加入3.5（A）G丙醇，得到白色沉淀物（第三级分，DAMC）。 </li><li>离心2.9的溶液在3000×g离心10分钟，并收集了凝胶状DAMC沉淀物（通过在一个单独的烧杯中倒出上清液）准备在水中再分散，通过透析纯化（在第4个可用的信息），并且其特征在于（第5节）。 </li></ol> 3. ENCC和DCC的合成<ol><li>在100毫升溶解制备0.5M的氢氧化钠（NaOH）的溶液中〜2克NaOH水，并保持它放在一边。这将在步骤3.7中使用。 </li><li>划分湿氧化纸浆，在1.11得到，由四个:M 3 = M 1/4，并测量吸收水的重量:M W，3 = 米3 - 1。 </li><li>另外，将添加2.93克氯化钠（NaCl）和1.41亚氯酸钠（次氯酸钠2） - （50 - 男女，3）毫升水搅拌溶解。 </li><li>暂停米3克在3.3中获得的溶液湿氧化处理的纸浆（含约1克干氧化纸浆）的。请注意，最终纸浆浓度为1g在50ml总可用水（游离和吸收水）。 </li><li>放置一个pH计在3.4的溶液中。 </li><li>添加1.41克过氧化氢 ​​（H 2 O 2）至步骤3.4中滴加该混合物。 </li><li>搅拌3.6在室温24小时的悬浮液在105转，同时通过逐渐加入在步骤3.1制得的0.5M氢氧化钠（NaOH）将pH保持〜5。 注:pH值开始减小，从反应开始后迅速〜15分钟，并且它应在5至少在反应的第一4小时保持恒定。为方便起见，它被认为该反应是在下午1点开始，将pH控制，直到下午5点，然​​后将反应是左的O / N和在上午将pH再增加到5月初。这么长的时间之后，pH值下降不会显著，表明大部分的转换得以实现。现在，几乎没有固体可在溶液中观察到的（大纤维被分解成纳米颗粒）。需要注意的是，如果反应在放置较长的时间，则结晶性部分可能会中断。 </li><li>划分从3.7 10分钟得到的成均等加权离心管中，离心以27,000 xg离心悬浮液中，并将上清液（ENCC + DCC）从微纤维的沉淀物分离。 </li><li>称重从3.8得到的上清液，并调用溶液质量（B）。 </li><li>慢慢加入0.16（B）G乙醇以3.9的溶液中，同时搅拌，形成白色沉淀物（第二级分，ENCC）。 </li><li>离心机的3.10在3000 xg离心10分钟的溶液中，并通过倾析分离所得凝胶状ENCC沉淀。 ENCC是准备在水中再分散，通过透析（在第4个可用的信息）进行纯化，并且其特征在于（第5部分）。 </li><li>以3.11得到的上清液中，添加乙醇等质量的溶液的质量，得到白色沉淀物（第三级分，DCC）。 </li><li>离心的3.12的溶液在3000×g离心10分钟，并分离凝胶状DCC沉淀准备在水中再分散，通过透析纯化（在第4个可用细节），并进行表征。 </li></ol> 4.透析过程净化SNCC，DAMC，ENCC或DCC <ol><li>剧烈搅拌1小时再分散在10ml水中2.8（SNCC）的任何步骤中得到的凝胶状沉淀物，2.10（DAMC），3.11（ENCC），或者3.13（DCC）。 </li><li>第广场在一个透析管e离散（分子量截留值= 12-14 kDa的，长度约30厘米，宽度约为4.5厘米），并通过夹紧固定的顶部和底部。 </li><li>放置在〜4升蒸馏水填充透析袋中，并搅拌24小时以喷射的盐。 </li><li>收集在冷的（4℃）处的容器和储存的透析溶液。 </li></ol> 5.后净化表征:固相和充电浓度测量<ol><li> 浓度测量 <ol><li>权衡的加权盘3毫升期望分散体（铝杯57毫米）。 </li><li>放置装有在烘箱（50℃）O / N分散体中的称量皿。 </li><li>称量干膜，并计算在分散纳米颗粒或聚合物的浓度: 浓度（重量/体积％）=干膜/ 3的100×质量，或 浓度（重量/重量％）=分散的干膜/质量100×质量</li></ol></li><li> 电导滴定 </st荣&gt; <ol><li> SNCC或DAMC确定醛含量的电导滴定 <ol><li>通过加入0.82毫升盐酸至25毫升水中，随后通过调节最终体积至100ml制备的0.1M盐酸（HCl）。 </li><li>单独地，通过将​​0.4克氢氧化钠至蒸馏水达到100 ml终溶液制备的NaOH的0.1M。 </li><li>继盐酸羟胺法24，所希望的分散体的公知的添加量的水所需量（ 例如和0.02克在50毫升H 2 O）。 </li><li>将pH调节至3.5使用稀盐酸（0.1M）。 </li><li>加入10 mL盐酸羟胺溶液（5％W / W）的分散液。 </li><li>监测pH值，并通过添加0.1M NaOH中直到pH变成3.5稳定保持在3.5。 </li><li>使用NaOH的消耗体积以中和从醛基和NH 2 OH·HCl的的反应中释放的H +测量醛concentra化（在反应过程中消耗的NaOH =摩尔产生的HCl的摩尔=上SNCC醛基摩尔）。 </li></ol></li><li> ENCC或DCC确定羧基含量的电导滴定 <ol><li>以下文献25中 ，添加所希望的分散体的足够量的有0.02克的固体140毫升蒸馏水。 </li><li>单独地，在蒸馏水中溶解0.117克NaCl达到100 ml终溶液制备20mM的NaCl洗涤。 2毫升20毫米氯化钠添加到5.2.2.1。 </li><li>降低pH值至约3用稀盐酸（0.1M）。 </li><li>通过以0.1毫升/分钟的增量加入标准氢氧化钠（NaOH，10毫摩尔）至pH〜11进行电导滴定。 </li><li>使用NaOH的消耗体积以中和电荷的基团（在图2中详细说明），测量表面电荷浓度（1摩尔消耗的碱的等于1摩尔羧基的粒子表面上）。 </li></ol></li></ol></li></ol>

<ol>
	<li>Habibi, Y., Lucia, L. A., Rojas, O. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellulose+nanocrystals:+Chemistry+,+self-Assembly+,+and+applications.">Cellulose nanocrystals: Chemistry , self-Assembly , and applications.</a> Chem. Rev. 110 (6), 3479-3500 (2010).</li><li>Samir, M. A. S. A., Alloin, F., Dufresne, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+of+recent+research+into+cellulosic+whisker,+their+Properties+and+their+application+in+nanocomposites+field.">Review of recent research into cellulosic whisker, their Properties and their application in nanocomposites field.</a> Biomacromolecules. 6 (2), 612-626 (2005).</li><li>Sj&#246;str&#246;m, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Wood chemistry: Fundamentals and applications. , (1993).</li><li>Nageli, C., Schwendener, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Das Mikroskop, Theorie und Anwendung desselben. 2. Verbesserte auflage. , (1877).</li><li>Moon, R. J., Martini, A., Nairn, J., Simonsen, J., Youngblood, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellulose+nanomaterials+review:+structure,+properties+and+nanocomposites.">Cellulose nanomaterials review: structure, properties and nanocomposites.</a> Chem. Soc. Rev. 40 (7), 3941-3994 (2011).</li><li>Klemm, D., Kramer, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanocelluloses:+A+new+family+of+nature-based+materials.">Nanocelluloses: A new family of nature-based materials.</a> Angew. Chem. Int. Ed. 50 (24), 5438-5466 (2011).</li><li>Wang, N., Ding, E., Cheng, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+modification+of+cellulose+nanocrystals.">Surface modification of cellulose nanocrystals.</a> Front. Chem. Eng. China. 1 (3), 228-232 (2007).</li><li>Siqueira, G., Bras, J., Dufresne, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellulosic+bionanocomposites:+A+review+of+preparation,+properties+and+applications.">Cellulosic bionanocomposites: A review of preparation, properties and applications.</a> Polymers. 2 (4), 728-765 (2010).</li><li>Siaueira, G., Bras, J., Dufresne, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellulose+whiskers+versus+microfibrils:+Influence+of+the+nature+of+the+nanoparticle+and+its+surface+functionalization+on+the+thermal+and+mechanical+properties+of+nanocomposites.">Cellulose whiskers versus microfibrils: Influence of the nature of the nanoparticle and its surface functionalization on the thermal and mechanical properties of nanocomposites.</a> Biomacromolecules. 10 (2), 425-432 (2009).</li><li>Peng, B. L., Dhar, N., Liu, H. L., Tam, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemistry+and+applications+of+nanocrystalline+cellulose+and+its+derivatives:+A+nanotechnology+perspective.">Chemistry and applications of nanocrystalline cellulose and its derivatives: A nanotechnology perspective.</a> Can. J. Chem. Eng. 89 (5), 1191-1206 (2011).</li><li>Lu, P., Hsieh, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lo+Preparation+and+properties+of+cellulose+nanocrystals:+Rods,+spheres,+and+network.">Lo Preparation and properties of cellulose nanocrystals: Rods, spheres, and network.</a> Carbohydr. Polym. 82 (2), 329-336 (2010).</li><li>Liu, D., Chen, X., Yue, Y., Chen, M., Wu, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+and+rheology+of+nanocrystalline+cellulose.">Structure and rheology of nanocrystalline cellulose.</a> Carbohydr. Polym. 84 (1), 316-322 (2011).</li><li>Lam, E., Male, K. B., Chong, J. H., Leung, A. C. W., Luong, J. H. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+functionalized+and+nanoparticle-modified+nanocrystalline+cellulose.">Applications of functionalized and nanoparticle-modified nanocrystalline cellulose.</a> Trends Biotechnol. 30 (5), 283-290 (2012).</li><li>Kalia, S., Dufresne, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellulose-based+bio-+and+nanocomposites:+A+review.">Cellulose-based bio- and nanocomposites: A review.</a> Int. J. Polym. Sci. 2011, 1-35 (2011).</li><li>Bai, W., Holbery, J., Li, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+technique+for+production+of+nanocrystalline+cellulose+with+a+narrow+size+distribution.">A technique for production of nanocrystalline cellulose with a narrow size distribution.</a> Cellulose. 16 (3), 455-465 (2009).</li><li>Eichhorn, S. J., Dufresne, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review:+Current+international+research+into+cellulose+nanofibres+and+nanocomposites.">Review: Current international research into cellulose nanofibres and nanocomposites.</a> J. Mater. Sci. 45 (1), 1-33 (2010).</li><li>Safari, S., Sheikhi, A., van de Ven, T. G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electroacoustic+characterization+of+conventional+and+electrosterically+stabilized+nanocrystalline+celluloses.">Electroacoustic characterization of conventional and electrosterically stabilized nanocrystalline celluloses.</a> J. Colloid Interface Sci. 432, 151-157 (2014).</li><li>Yang, H., Tejado, A., Alam, N., Antal, M., Van De Ven, T. G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Films+prepared+from+electrosterically+stabilized+nanocrystalline+cellulose.">Films prepared from electrosterically stabilized nanocrystalline cellulose.</a> Langmuir. 28 (20), 7834-7842 (2012).</li><li>Guthrie, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+&amp;#34;dialdehydes&amp;#34;+from+the+periodate+oxidation+of+carbohydrates.">The &amp;#34;dialdehydes&amp;#34; from the periodate oxidation of carbohydrates.</a> Adv Carbohydr Chem. 16, 105-158 (1961).</li><li>van de Ven, T. G. M., Tejado, A., Alam, M. N., Antal, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+highly+charged+non-water+soluble+cellulose+products,+includes+all+types+of+cellulose+nanostructures+especially+cellulose+nanofibers,+and+method+of+making+them.">Novel highly charged non-water soluble cellulose products, includes all types of cellulose nanostructures especially cellulose nanofibers, and method of making them.</a> U.S. Provisional Patent Application. , (2011).</li><li>Yang, H., Chen, D., van de Ven, T. G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+characterization+of+sterically+stabilized+nanocrystalline+cellulose+obtained+by+periodate+oxidation+of+cellulose+fibers.">Preparation and characterization of sterically stabilized nanocrystalline cellulose obtained by periodate oxidation of cellulose fibers.</a> Cellulose. 22 (3), 1743-1752 (2015).</li><li>Sheikhi, A., Safari, S., Yang, H., van de Ven, T. G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Copper+removal+using+electrosterically+stabilized+nanocrystalline+cellulose.">Copper removal using electrosterically stabilized nanocrystalline cellulose.</a> ACS Appl. Mater. Interfaces. 7 (21), 11301-11308 (2015).</li><li>Yang, H., Alam, M. N., van de Ven, T. G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+charged+nanocrystalline+cellulose+and+dicarboxylated+cellulose+from+periodate+and+chlorite+oxidized+cellulose+fibers.">Highly charged nanocrystalline cellulose and dicarboxylated cellulose from periodate and chlorite oxidized cellulose fibers.</a> Cellulose. 20 (4), 1865-1875 (2013).</li><li>Kim, U. J., Kuga, S., Wada, M., Okano, T., Kondo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Periodate+oxidation+of+crystalline+cellulose.">Periodate oxidation of crystalline cellulose.</a> Biomacromolecules. 1 (3), 488-492 (2000).</li><li>Araki, J., Wada, M., Kuga, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Steric+stabilization+of+a+cellulose+microcrystal+suspension+by+poly+(ethylene+glycol)+grafting.">Steric stabilization of a cellulose microcrystal suspension by poly (ethylene glycol) grafting.</a> Cellulose. 17 (1), 21-27 (2001).</li></ol>

The authors have nothing to disclose.

以下在此视觉本文所讨论的化学，高度稳定的基于纤维素的纳米颗粒的具有可调电荷轴承结晶和非结晶相（毛状纳米晶纤维素）的频谱产生。取决于碘酸氧化时间，如表1所示，各种产品，得到:氧化纤维（级分1），SNCC（级分2），和DAMC（馏分3），其每个提供独特的性能，如所定义的大小，形态，结晶度，和醛含量。在各种带负电荷的物质，即馏分1（羧化的纸浆纤维），级分2（ENCC）?...

纤维素，如在世界上最丰富的生物聚合物，已被最近担任一个关键原料，得到命名纳米晶纤维素晶体纳米颗粒（NCC，也被称为纤维素纳米晶体的CNC）1。理解NCC合成的机理，需要探索纤维素纤维的结构。纤维素是直链和包含聚β-（1,4）-D-葡萄糖残基2多分散聚合物。在各单体的糖环通过糖苷氧连接形成的（1-1.5）链×10 4个吡喃葡萄糖单元2,3，引入交替结晶份和无序的，无定形的区域，首先通过Nageli和施文德纳2,4报道。取决于来源，纤维素的结晶部分可以采取多种多晶型5。 如果纤维素纤维是用强酸处理，如硫酸，非晶相可以是完全水解AWAy以扰乱聚合物并产生取决于来源各种长宽比的晶体颗粒（ 例如 ，宽度的木材和棉花产量的90％以上的结晶纳米棒〜5-10纳米，长度〜100-300纳米，而tunicin，细菌，和藻类产生5-60纳米宽，100纳米至微米几个长NCC的）6。读者可参考在这些纳米材料2,5,7-16的科学和工程方面提供了大量的文学作品。尽管这些纳米颗粒的许多有趣的性质，它们的胶体稳定性一直在高盐浓度和高/低pH值的问题，由于其相对低的表面电荷量（小于1毫摩尔/克）17。 代替强酸水解，纤维素纤维可以用氧化剂（高碘）进行处理，在脱水-D-吡喃葡萄糖残基裂解的C 2 -C 3键以形成2,3-二醛单元无显著副反应18,19。这些部分氧化的纤维可以被用来作为一种有价值的中间体材料以产生仅仅使用化学反应的纳米颗粒轴承非晶和结晶区域（毛状纳米晶纤维素），无需任何机械剪切或超声处理20。当部分氧化度DS &lt;2，加热氧化中的产品，即纤维状纤维素，水分散性二醛纤维素纳米晶须称为空间稳定的纳米晶纤维素（SNCC）三批纤维的结果，并溶解二醛改性纤维素（DAMC），其可以分离通过在共溶剂加成和精确控制间歇离心21。 对所述部分氧化的纤维受控氯酸盐氧化转换几乎所有的醛基至羧基单元，它可以为每克微晶纤维素引入高达7毫摩尔COOH基团视醛含量18 </suP&gt;，作为稳定剂。这些纳米颗粒被称为electrosterically稳定纳米晶纤维素（ENCC）。此外，已经证实，带电毛发状凸出链软层上ENCC 17存在。这种材料已被用来作为一种高效吸附剂来清除重金属离子22。电荷这些纳米颗粒能够通过控制高碘反应时间23被精确地控制。 尽管纤维素的已知氧化还原反应，生产SNCC和ENCC的从未报道过的任何其他研究小组最可能是由于在分离的挑战。我们已经能够成功地合成和通过精确设计的反应和分离步骤分离纳米产品的各种馏分。这种视觉文章完整详细演示了如何重现性准备和表征上述新型纳米晶须轴承非晶和晶体部分期从木质纤维。本教程可能是在软质材料，生物和医药科学，纳米技术和纳米光子学，环境科学与工程和物理学领域活跃的研究人员的资产。

<table><tbody><tr><td>Q-90 softwood pulp</td><td>FPInnovations</td><td>-</td><td>-</td></tr><tr><td>Sodium periodate</td><td>Sigma-Aldrich</td><td>S1878-500G/CAS7790-28-5</td><td>Light sensitive, strong oxidizer, must be kept away from flammable materials</td></tr><tr><td>Sodium chloride</td><td>ACP Chemicals</td><td>S2830-3kg/7647-14-5</td><td>-</td></tr><tr><td>2-Propanol</td><td>Fisher</td><td>L-13597/67-63-0</td><td>Flammable</td></tr><tr><td>Ethylene glycol</td><td>Sigma-Aldrich</td><td>102466-1L/107-21-1</td><td>-</td></tr><tr><td>Sodium hydroxide</td><td>Fisher</td><td>L-19234/1310-73-2</td><td>Strong base, causes serious health effects</td></tr><tr><td>Sodium chlorite</td><td>Sigma-Aldrich</td><td>71388-250G/7758-19-2</td><td>Reactive with reducing agents and combustible materials</td></tr><tr><td>Hydrogen peroxide</td><td>Fisher</td><td>H325-500/7722-84-1</td><td>Corrosive and oxidizing agent, keep in a cool and dark place</td></tr><tr><td>Ethanol</td><td>Commercial alcohols</td><td>P016EAAN</td><td>Flammable</td></tr><tr><td>Hydrochloric acid</td><td>ACP Chemicals</td><td>H-6100-500mL/7647-01-0</td><td>Strong acid, causes serious health effects</td></tr><tr><td>Hydroxylamine hydrochloride</td><td>Sigma-Aldrich</td><td>159417-100G/5470-11-1</td><td>Unstable at high temperature and humidity, mutagenic</td></tr><tr><td>Centrifuge</td><td>Beckman Coulter</td><td>J2</td><td>High rotary speed</td></tr><tr><td>Fixed angle rotor</td><td>Beckman Coulter</td><td>JA-25.50</td><td>Tighten the lid carefully</td></tr><tr><td>Dialysis tubing</td><td>Spectrum Labs</td><td>Spectra (Part No. 132676)</td><td>Cutoff Mw = 12-14 kD, Length ~ 30 cm, width ~ 4.5 cm</td></tr><tr><td>Aluminum cup</td><td>VWR</td><td>611-1371</td><td>57 mm</td></tr><tr><td>Titrator</td><td>Metrohm</td><td>836 Titrando</td><td>-</td></tr></tbody></table>

highly stable, functional hairy nanoparticles and biopolymers from wood fibers: towards sustainable nanotechnology

纳米粒子，如纳米技术和纳米医学的关键材料之一，在过去十年中取得了显著的重要性。虽然基于金属纳米粒子合成和环境相关的麻烦，纤维素引入了纳米粒子合成一个绿色，可持续的替代。这里，我们提出的化学合成和分离程序以基于木材纤维毛的纳米颗粒（轴承非晶和结晶区域）和生物聚合物的新类。通过软木浆的高碘酸盐氧化，纤维素的葡萄糖环的C 2 -C 3键被打开以形成2,3-二醛基。部分氧化的纤维进一步加热（ 例如 ，T = 80℃）的结果在三个产品，即纤维状氧化纤维素，空间稳定的纳米晶纤维素（SNCC），并溶解二醛改性纤维素（DAMC），这是公通过间歇离心分离和共溶剂加成。部分氧化的纤维（不加热）被用作一个高反应性的中间产物以用亚反应转换几乎所有醛的羧基。共溶剂沉淀和离心导致electrosterically稳定纳米晶纤维素（ENCC）和二羧基化纤维素（DCC）。 SNCC因此表面电荷ENCC（羧基含量）被精确地通过控制碘酸氧化反应时间，从而导致高度稳定的纳米颗粒的轴承每克的纳米颗粒（ 如超过700毫摩尔的官能团，受控的醛的含量比常规NCC轴承&lt;&lt; 1毫摩尔官能团/克）。原子力显微镜（AFM），透射电子显微镜（TEM）和扫描电子显微镜（SEM）证明了棒状的形态。电导滴定，傅立叶变换红外光谱（FTIR），核磁共振（NMR），动态光散射（DLS），电动 - S的ONIC振幅（ESA）和声衰减谱棚光对这些纳米材料的优异性能。

纸浆的高碘和绿泥石氧化期间每个部分的质量部分和电荷含量取决于反应时间（ 见表1）。此外，DAC分子量取决于加热条件和停留时间（ 见表2）。一旦SNCC和DAMC制成，它们通过添加丙醇（ 图1）中沉淀出来。为了测量ENCC的电荷内容，电导滴定进行（ 图2）。 NCC和ENCC胶体行为由离子强度和pH的影响。的大小和NCC和ENCC与氯化?...

Watch this Scientific Journal Video about Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology at JoVE.com

Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology

Synthesis schemes to prepare highly stable wood fiber-based hairy nanoparticles and functional cellulose-based biopolymers have been detailed.

高稳定性，功能性毛纳米粒子和木纤维生物聚合物:迈向可持续纳米技术

Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While ...

highly-stable-functional-hairy-nanoparticles-biopolymers-from-wood

Universidad San Sebastian

Research

JoVE Journal

Chemistry

11.9K 次观看.  McGill University. Synthesis schemes to prepare highly stable wood fiber-based hairy nanoparticles and functional cellulose-based biopolymers have been detailed. 

视频: Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology

Towards Biomimicking Wood: Fabricated Free-standing Films of Nanocellulose, Lignin, and a Synthetic Polycation

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and lignin. Layer-by-layer (LbL) assembly process which relies on the assembly of oppositely charged molecules from aqueous solutions was used to build a freestanding composite film of isolated wood polymers of lignin and oxidized nanofibril cellulose (NFC). To facilitate the assembly of these negatively charged polymers, a positively charged polyelectrolyte, poly(diallyldimethylammomium chloride) (PDDA), was used as a linking layer to create this simplified model cell wall. The layered adsorption process was studied quantitatively using quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry. The results showed that layer mass/thickness per adsorbed layer increased as a function of total number of layers. The surface coverage of the adsorbed layers was studied with atomic force microscopy (AFM). Complete coverage of the surface with lignin in all the deposition cycles was found for the system, however, surface coverage by NFC increased with the number of layers. The adsorption process was carried out for 250 cycles (500 bilayers) on a cellulose acetate (CA) substrate. Transparent free-standing LBL assembled nanocomposite films were obtained when the CA substrate was later dissolved in acetone. Scanning electron microscopy (SEM) of the fractured cross-sections showed a lamellar structure, and the thickness per adsorption cycle (PDDA-Lignin-PDDA-NC) was estimated to be 17 nm for two different lignin types used in the study. The data indicates a film with highly controlled architecture where nanocellulose and lignin are spatially deposited on the nanoscale (a polymer-polymer nanocomposites), similar to what is observed in the native cell wall.

The objective of this research was to form synthetic plant cell wall tissue using layer-by-layer assembly of nanocellulose fibrils and isolated lignin assembled from dilute aqueous suspensions.&#160; Surface measurement techniques of quartz crystal microbalance and atomic force microscopy were used to monitor the formation of the polymer-polymer nanocomposite material.

朝仿生学木：纳米纤维素，木质素的装配式自由站立电影和合成聚阳离子

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and ...

科研

化学

Functionalization and Dispersion of Carbon Nanomaterials Using an Environmentally Friendly Ultrasonicated Ozonolysis Process

Functionalization of carbon nanomaterials is often a critical step that facilitates their integration into larger material systems and devices. In the as-received form, carbon nanomaterials, such as carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs), may contain large agglomerates. Both agglomerates and impurities will diminish the benefits of the unique electrical and mechanical properties offered when CNTs or GNPs are incorporated into polymers or composite material systems. Whilst a variety of methods exist to functionalize carbon nanomaterials and to create stable dispersions, many the processes use harsh chemicals, organic solvents, or surfactants, which are environmentally unfriendly and may increase the processing burden when isolating the nanomaterials for subsequent use. The current research details the use of an alternative, environmentally friendly technique for functionalizing CNTs and GNPs. It produces stable, aqueous dispersions free of harmful chemicals. Both CNTs and GNPs can be added to water at concentrations up to 5 g/L and can be recirculated through a high-powered ultrasonic cell. The simultaneous injection of ozone into the cell progressively oxidizes the carbon nanomaterials, and the combined ultrasonication breaks down agglomerates and immediately exposes fresh material for functionalization. The prepared dispersions are ideally suited for the deposition of thin films onto solid substrates using electrophoretic deposition (EPD). CNTs and GNPs from the aqueous dispersions can be readily used to coat carbon- and glass-reinforcing fibers using EPD for the preparation of hierarchical composite materials.

Here, a novel method for the functionalization and stable dispersion of carbon nanomaterials in aqueous environments is described. Ozone is injected directly into an aqueous dispersion of carbon nanomaterial that is continuously recirculated through a high-powered ultrasonic cell.

碳纳米材料的功能化和分散使用环境友好的超声波臭氧分解过程

Functionalization of carbon nanomaterials is often a critical step that facilitates their integration into larger material systems and devices. In the ...

环境科学

Functionalization of Single-walled Carbon Nanotubes with Thermo-reversible Block Copolymers and Characterization by Small-angle Neutron Scattering

We demonstrate a protocol for single-walled carbon nanotube functionalization using thermo-sensitive PEO-PPO-PEO triblock copolymers in an aqueous solution. In a carbon nanotube/PEO105-PPO70-PEO105 (poloxamer 407) aqueous solution, the amphiphilic poloxamer 407 adsorbs onto the carbon nanotube surfaces and self-assembles into continuous layers, driven by intermolecular interactions between constituent molecules. The addition of 5-methylsalicylic acid changes the self-assembled structure from spherical-micellar to a cylindrical morphology. The fabricated poloxamer 407/carbon nanotube hybrid particles exhibit thermo-responsive structural features so that the density and thickness of poloxamer 407 layers are also reversibly controllable by varying temperature. The detailed structural properties of the poloxamer 407/carbon nanotube particles in suspension can be characterized by small-angle neutron scattering experiments and model fit analyses. The distinct curve shapes of the scattering intensities depending on temperature control or addition of aromatic additives are well described by a modified core-shell cylinder model consisting of a carbon nanotube core cylinder, a hydrophobic shell, and a hydrated polymer layer. This method can provide a simple but efficient way for the fabrication and in-situ characterization of carbon nanotube-based nano particles with a structure-tunable encapsulation.

A method for the functionalization of carbon nanotubes with structure-tunable polymeric encapsulation layers and structural characterization using small-angle neutron scattering is presented.

单壁碳纳米管与热可逆嵌段共聚物及表征功能化小角度中子散射

We demonstrate a protocol for single-walled carbon nanotube functionalization using thermo-sensitive PEO-PPO-PEO triblock copolymers in an aqueous ...

Nanosponge Tunability in Size and Crosslinking Density

We describe a protocol for the synthesis of linear polyesters containing pendant epoxide functionality and their incorporation into a nanosponge with controlled dimensions. This approach begins with synthesis of a functionalized lactone which is key to the pendant functionalization of the resulting polymer. Valerolactone (VL) and allyl-valerolactone (AVL) are then copolymerized using ring-opening polymerization. Post-polymerization modification is then used to install an epoxide moiety on some or all of the pendant allyl groups. Epoxy-amine chemistry is employed to form nanoparticles in a dilute solution of both polymer and small molecule diamine crosslinker based on the desired nanosponge size and crosslinking density. Nanosponge sizes can be characterized by transmission electron microscopy (TEM) imaging to determine the dimension and distribution. This method provides a pathway by which highly tunable polyesters can create tunable nanoparticles, which can be used for small molecule drug encapsulation. Due to the nature of the backbone, these particles are hydrolytically and enzymatically degradable for a controlled release of a wide range of hydrophobic small molecules.

This article describes a process for tuning the size and crosslinking density of covalently crosslinked nanoparticles from linear polyesters containing pendant functionality. By tailoring synthesis parameters (polymer molecular weight, pendant functionality incorporation, and crosslinker equivalents), a desired nanoparticle size and crosslinking density can be achieved for drug delivery applications.

Nanosponge 可调大小和交联密度

We describe a protocol for the synthesis of linear polyesters containing pendant epoxide functionality and their incorporation into a nanosponge with ...

Manufacturing Of Robust Natural Fiber Preforms Utilizing Bacterial Cellulose as Binder

A novel method of manufacturing rigid and robust natural fiber preforms is presented here. This method is based on a papermaking process, whereby loose and short sisal fibers are dispersed into a water suspension containing bacterial cellulose. The fiber and nanocellulose suspension is then filtered (using vacuum or gravity) and the wet filter cake pressed to squeeze out any excess water, followed by a drying step. This will result in the hornification of the bacterial cellulose network, holding the loose natural fibers together.
Our method is specially suited for the manufacturing of rigid and robust preforms of hydrophilic fibers. The porous and hydrophilic nature of such fibers results in significant water uptake, drawing in the bacterial cellulose dispersed in the suspension. The bacterial cellulose will then be filtered against the surface of these fibers, forming a bacterial cellulose coating. When the loose fiber-bacterial cellulose suspension is filtered and dried, the adjacent bacterial cellulose forms a network and hornified to hold the otherwise loose fibers together.
The introduction of bacterial cellulose into the preform resulted in a significant increase of the mechanical properties of the fiber preforms. This can be attributed to the high stiffness and strength of the bacterial cellulose network. With this preform, renewable high performance hierarchical composites can also be manufactured by using conventional composite production methods, such as resin film infusion (RFI) or resin transfer molding (RTM). Here, we also describe the manufacturing of renewable hierarchical composites using double bag vacuum assisted resin infusion.

We present a novel method of manufacturing rigid and robust short natural fiber preforms using a papermaking process. Bacterial cellulose acts simultaneously as the binder for the loose fibers and provides rigidity to the fiber preforms. These preforms can be infused with a resin to produce truly green hierarchical composites.

制造业的鲁棒天然纤维预制体的利用细菌纤维素为粘结剂

A novel method of manufacturing rigid and robust natural fiber preforms is presented here. This method is based on a papermaking process, whereby loose ...

生物工程

Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial applications. Here we describe how electrospinning or electrospraying a polymer mixture containing a biodegradable, biocompatible aliphatic polyester (e.g., polycaprolactone and poly(lactide-co-glycolide)), as the major component, doped with a hydrophobic copolymer composed of the polyester and a stearate-modified poly(glycerol carbonate) affords a superhydrophobic biomaterial. The fabrication techniques of electrospinning or electrospraying provide the enhanced surface roughness and porosity on and within the fibers or the particles, respectively. The use of a low surface energy copolymer dopant that blends with the polyester and can be stably electrospun or electrosprayed affords these superhydrophobic materials. Important parameters such as fiber size, copolymer dopant composition and/or concentration, and their effects on wettability are discussed. This combination of polymer chemistry and process engineering affords a versatile approach to develop application-specific materials using scalable techniques, which are likely generalizable to a wider class of polymers for a variety of applications.

Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition.

制造超疏水高分子材料生物医学应用

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial ...

Synthesis of Keratin-based Nanofiber for Biomedical Engineering

Electrospinning, due to its versatility and potential for applications in various fields, is being frequently used to fabricate nanofibers. Production of these porous nanofibers is of great interest due to their unique physiochemical properties. Here we elaborate on the fabrication of keratin containing poly (&#949;-caprolactone) (PCL) nanofibers (i.e., PCL/keratin composite fiber). Water soluble keratin was first extracted from human hair and mixed with PCL in different ratios. The blended solution of PCL/keratin was transformed into nanofibrous membranes using a laboratory designed electrospinning set up. Fiber morphology and mechanical properties of the obtained nanofiber were observed and measured using scanning electron microscopy and tensile tester. Furthermore, degradability and chemical properties of the nanofiber were studied by FTIR. SEM images showed uniform surface morphology for PCL/keratin fibers of different compositions. These PCL/keratin fibers also showed excellent mechanical properties such as Young&#39;s modulus and failure point. Fibroblast cells were able to attach and proliferate thus proving good cell viability. Based on the characteristics discussed above, we can strongly argue that the blended nanofibers of natural and synthetic polymers can represent an excellent development of composite materials that can be used for different biomedical applications.

Electrospun nanofibers have a high surface area to weight ratio, excellent mechanical integrity, and support cell growth and proliferation. These nanofibers have a wide range of biomedical applications. Here we fabricate keratin/ PCL nanofibers, using the electrospinning technique, and characterize the fibers for possible applications in tissue engineering.

基于角蛋白纳米纤维生物医学工程合成

Electrospinning, due to its versatility and potential for applications in various fields, is being frequently used to fabricate nanofibers. Production of ...

Fabrication and Design of Wood-Based High-Performance Composites

Delignified densified wood is a new promising and sustainable material that possesses the potential to replace synthetic materials, such as glass fiber reinforced composites, due to its excellent mechanical properties. Delignified wood, however, is rather fragile in a wet state, which makes handling and shaping challenging. Here we present two fabrication processes, closed-mold densification and vacuum densification, to produce high-performance cellulose composites based on delignified wood, including an assessment of their advantages and limitations. Further, we suggest strategies for how the composites can be re-used or decomposed at the end-of-life cycle. Closed-mold densification has the advantage that no elaborate lab equipment is needed. Simple screw clamps or a press can be used for densification. We recommend this method for small parts with simple geometries and large radii of curvature. Vacuum densification in an open-mold process is suitable for larger objects and complex geometries, including small radii of curvature. Compared to the closed-mold process, the open-mold vacuum approach only needs the manufacture of a single mold cavity.

Delignified densified wood represents a new promising lightweight, high-performance and bio-based material with great potential to partially substitute natural fiber reinforced- or glass fiber reinforced composites in the future. We here present two versatile fabrication routes and demonstrate the possibility to create complex composite parts.

基于木材的高性能复合材料的制造与设计

Delignified densified wood is a new promising and sustainable material that possesses the potential to replace synthetic materials, such as glass fiber ...

工程学

Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer

The development of chemically recyclable biopolymers offers opportunities within the pursuit of a circular economy. Chemically recyclable biopolymers make a positive effort to solve the issue of polymer materials in the disposal phase after the use phase. In this paper, the production of biobased semi-aromatic polyesters, which can be extracted entirely from biomass such as lignin, is described and visualized. The polymer poly-S described in this paper has thermal properties similar to certain commonly used plastics, such as PET. We developed a Green Knoevenagel reaction, which can efficiently produce monomers from aromatic aldehydes and malonic acid. This reaction has been proven to be scalable and has a remarkably low calculated E-factor. These polyesters with ligno-phytochemicals as a starting point show an efficient molecular recycling with minimal losses. The polyester poly(dihydrosinapinic acid) (poly-S) is presented as an example of these semi-aromatic polyesters, and the polymerization, depolymerization, and re-polymerization are described.

An example of a closed-loop approach towards a circular materials economy is described here. A whole sustainable cycle is presented where biobased semi-aromatic polyesters are designed by polymerization, depolymerization, and then re-polymerized with only slight changes in their yields or final properties.

专为分子回收而设计:一种褐宁衍生的半芳烃生物基聚合物

The development of chemically recyclable biopolymers offers opportunities within the pursuit of a circular economy. Chemically recyclable biopolymers make ...

用于生物类黄酮释放的木质素微/亚微米颗粒合成

Green Synthesis, Characterization, Encapsulation, and Measurement of the Release Potential of Novel Alkali Lignin Micro-/Submicron Particles

The applicability of biopolymer micro-/nano- technology in human, veterinary medicine, pharmaceutical, and food technology is rapidly growing due to the great potential of biopolymer-based particles as effective carrier systems. The use of lignin as a basic heteropolymer biomatrix for the design of innovative micro-/submicron formulations allows the achievement of increased biocompatibility and offers various active functional groups presenting opportunities for customization of the physicochemical properties and bioactivities of the formulations for diverse applications. The aim of the present study was to develop a simple and ecofriendly methodology for the synthesis of lignin particles with micro- and submicron size; to evaluate their physicochemical, spectral, and structural characteristics; and to examine their capacity for encapsulation of biologically active molecules and potential for in vitro release of bioflavonoids in simulated gastrointestinal media. The presented methodologies apply cheap and green solvents; easy, straightforward, quick, and sensitive processes requiring little equipment, non-toxic substances, and simple methods for their characterization, the determination of encapsulation capacity towards the poorly water-soluble bioactive compounds morin and quercetin, and the in vitro release potential of the lignin matrices.

作者聚焦：用于增强生物类黄酮递送的环保木质素基微粒的开发和表征

We describe novel, simple methodologies of synthesis and characterization of biocompatible lignin micro- and submicron particles. These formulations provide a facile approach for the utilization of the heteropolymer, as well as an alternative for the rational design of multifunctional carrier matrices with potential applicability in biomedicine, pharmaceutical technology, and the food industry.

新型碱木质素微/亚微米颗粒的绿色合成、表征、封装和释放潜力的测量

The applicability of biopolymer micro-/nano- technology in human, veterinary medicine, pharmaceutical, and food technology is rapidly growing due to the ...