Name: green and low-cost production of thermally stable and carboxylated cellulose nanocrystals and nanofibrils using highly recyclable dicarboxylic acids
Uploaded: 2017-01-09T14:00:00.000+00:00
Duration: 7 min 25 s
Description: Watch this Scientific Journal Video about Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids at JoVE.c

这项工作是卞的同时，陈，王均博士来访进行学生在美国林务局，林产品实验室（FPL），麦迪逊，并在朱的政府官方时间。这项工作是部分由美国农业部农业和食品研究计划（AFRI）竞争性赠款（2011-67009-20056号），中国国家林业局（项目编号:2015-4-54），国家自然科学基金资助中国（项目编号:31470599），中国广州精英项目，以及中国奖学基金。从这些项目的资金在FPL可能做边，陈，王来访的任命。

注意:漂白桉木浆（BEP），并从商业渠道漂白混合阔叶牛皮浆（UMHP）纤维作为原料用于生产CNC和CNF。购买的商业马来酸被用于水解。水解条件为:60重量％的酸浓度，在100℃进行60分钟和120分钟120℃（在大气压下没有沸点），对BEP和UMHP分别。 1.浓二元酸溶液的制备<ol><li>热40毫升在加热板上于约85℃的液体甘油浴去离子在多颈烧瓶（DI）水。 </li><li>添加60克无水马来酸到烧瓶中，使用磁力搅拌的60％（重量）溶液。使用酸溶液的先前报道15的密度，计算所需的水和酸量为使得在指定的质量浓度的酸溶液。 </li><li>加热该溶液到解100或120℃sired水解温度（不沸腾由于高二元酸的浓度）。 </li></ol> 2.水解反应<ol><li>一旦该酸溶液是在温度，添加的BEP或UMHP纤维为10克烘干（OD）与连续搅拌80毫升二羧酸溶液（1.1）。 <ol><li>通过加入80℃的去离子水160毫升终止水解之前采取在60分钟的规定的反应时间结束时的酸水解产物（约2毫升）的等分试样。 </li></ol></li><li>稀释0.5毫升抽样水解糖和酸浓度分析。 15观察结晶发生，同时咕咕至室温剩余水解产物样品。 </li><li>通过在布氏漏斗用滤纸真空过滤分离从水解纸浆的水解产物。 注:此分离所需要的温度下降之前相当快发生，而酸轧花结晶出来的溶液。由于从酸溶液中高离子强度，CNC的产生的水解凝聚和留在FCSR残差。约该酸的80-90％会与滤液中除去。 </li></ol> 3.数控分离<ol><li>从洗净2节使用去离子水滤出的固体并稀释至用去离子水大约1％的总固体。离心滤液在11960×g离心10分钟。 </li><li>滗掉上清液。重复使用新鲜的DI水，直到上清液是浑浊的洗涤和过滤过程。浊度表示该溶液的离子强度已经降至足够使CNC分散并开始变得胶体。 </li><li>混合与结算水解浆（2.3）浑浊的上清液。透析的透析袋（MWCO 14 kDa）的使用去离子水，直到该液体的导电率接近于DI水的混合物中。采用电导仪测量电导率。 </li><li>离心机在3500×g离心10分钟，得到在水相中数控分散体中的透析样品。保留沉淀相， 即 FCSR，为CNF生产。 </li><li>确定来自数控使用是COD方法分散液中的测定量的数控收率先前描述3,18。 </li></ol> 4.生产CNF <ol><li>分离CNC分散后确定沉淀FCSR由重力测量产量。干燥在105℃的FCSR并测量FCSR相对BEP或UMHP纤维使用的初始烘干重的烘箱干燥重量。 </li><li>通过连续传递悬浮液3次通过200微米的孔室随后2次通过87微米的孔室，所有在100兆帕机械原纤化在0.5％的纤维悬浮液的FCSR。 </li></ol> 5.原子力显微镜（AFM）成像<ol><li>超声处理约0.01％（重量）CNC或CNF小号uspensions 2分钟。沉积分散悬浮液的云母基板上的下降。风干在环境温度下沉积的悬浮液中。 </li><li>取风干的CNC和的CNFs的AFM图像中振动使用制造商的协议轻敲模式。分析使用商业软件获得的直径和长度分布大约100个独立的CNC或在的CNFs原子力显微镜图像。 </li></ol> 6.傅立叶变换推断（FTIR）测量<ol><li>使用商业红外分光光度计通用的衰减，全反射（ATR）探头来分析产生的CNC和CNF样品与原BEP和UMHP纤维识别酯基团一起。 </li><li>记录样品的吸收光谱在450之间的波长范围内- 4000厘米-1的4 -1和4扫描每个样品的分辨率。 </li></ol> 7.电导滴定<ol><li>使用电导滴定至QUAntify羧基样品组内容源于酯化由二羧酸。 </li><li>添加数控或CNF悬浮液与50mg（OD）的CNC或的CNFs的成1的120毫升的20mM NaCl溶液。通过以30秒的间隔将约0.2毫升2mM的NaOH溶液滴定该混合物。 </li><li>测量使用电导计的导电性。加入NaOH过程中找到的电导率曲线拐点（最低点）。 </li><li>计算基于所消耗的NaOH相对于使用以下等式其中c是NaOH溶液（摩尔/升）浓度的拐点上的羧基量（mmol / L）的量，v是加入NaOH溶液体积（毫升），m为CNC控制器或的CNFs的外径重量（克质量）。 <img alt="方程" src="/files/ftp_upload/55079/55079eq1.jpg" /></li></ol> 8. CNC和CNF热稳定性测定<ol><li>进行的t热降解测量他CNC和CNF通过热重分析（TGA）的样品。 </li><li>清除用高纯度的氮气流炉以20毫升/分钟，以防止任何不希望的氧化分解。干燥的样品在50℃下进行测试之前4小时。在干重使用的5毫克样品尺寸。 </li><li>记录样品的重量为炉温以10℃/分钟的加热速率上升，从室温至600℃。 </li><li>正常化由初始重量所测量的重量损失。 </li><li>进行CNC和CNF样品的单独的热稳定性测试中，在105℃的烘箱。后4小时和24小时通过常规的摄影记录样品的颜色变化。 </li></ol> 9. X射线衍射<ol><li>按冻干数控或CNF样品在180兆帕如前所述使粒料。 38 - 5行为广角上使用在102θ范围内的X射线衍射装置的Cu-Kα射线的粒料的X射线衍射测量在°0.02°步骤。 </li><li>计算使用西格尔方法19的粒料的结晶度指数（CRI）（无基线减法）。 </li></ol>

<ol>
	<li>Giese, M., Blusch, L. K., Khan, M. K., MacLachlan, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+Materials+from+Cellulose-Derived+Liquid-Crystal+Templates.">Functional Materials from Cellulose-Derived Liquid-Crystal Templates.</a> Angew Chem Int Ed. 54 (10), 2888-2910 (2015).</li><li>Zhu, H., 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=Wood-Derived+Materials+for+Green+Electronics,+Biological+Devices,+and+Energy+Applications+.">Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications .</a> Chem. Rev. , (2016).</li><li>Wang, Q. Q., 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=Approaching+zero+cellulose+loss+in+cellulose+nanocrystal+(CNC)+production:+recovery+and+characterization+of+cellulosic+solid+residues+(CSR)+and+CND.">Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CND.</a> Cellulose. 19 (6), 2033-2047 (2012).</li><li>Hamad, W. Y., Hu, T. 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-process-yield+interrelations+in+nanocrystalline+cellulose+extraction.">Structure-process-yield interrelations in nanocrystalline cellulose extraction.</a> Can J Chem Eng. 88 (3), 392-402 (2010).</li><li>Chen, L. H., 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=Tailoring+the+yield+and+characteristics+of+wood+cellulose+nanocrystals+(CNC)+using+concentrated+acid+hydrolysis.">Tailoring the yield and characteristics of wood cellulose nanocrystals (CNC) using concentrated acid hydrolysis.</a> Cellulose. 22 (3), 1753-1762 (2015).</li><li>Mukherjee, S. M., Woods, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=X-ray+and+electron+microscope+studies+of+the+degradation+of+cellulose+by+sulphuric+acid.">X-ray and electron microscope studies of the degradation of cellulose by sulphuric acid.</a> Biochim Biophys Acta. 10 (4), 499-511 (1953).</li><li>Camarero Espinosa, S., Kuhnt, T., Foster, E. J., Weder, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+thermally+stable+cellulose+nanocrystals+by+phosphoric+acid+hydrolysis.">Isolation of thermally stable cellulose nanocrystals by phosphoric acid hydrolysis.</a> Biomacromolecules. 14 (4), 1223-1230 (2013).</li><li>Yu, H. Y., 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=Facile+extraction+of+thermally+stable+cellulose+nanocrystals+with+a+high+yield+of+93%+through+hydrochloric+acid+hydrolysis+under+hydrothermal+conditions.">Facile extraction of thermally stable cellulose nanocrystals with a high yield of 93% through hydrochloric acid hydrolysis under hydrothermal conditions.</a> J Mater Chem, A. 1 (12), 3938-3944 (2013).</li><li>Leung, A. C. W., 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=Characteristics+and+properties+of+carboxylated+cellulose+nanocrystals+prepared+from+a+novel+one-step+procedure.">Characteristics and properties of carboxylated cellulose nanocrystals prepared from a novel one-step procedure.</a> Small. 7 (3), 302-305 (2011).</li><li>Saito, T., Isogai, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TEMPO-mediated+oxidation+of+native+cellulose.+The+effect+of+oxidation+conditions+on+chemical+and+crystal+structures+of+the+water-insoluble+fractions.">TEMPO-mediated oxidation of native cellulose. The effect of oxidation conditions on chemical and crystal structures of the water-insoluble fractions.</a> Biomacromolecules. 5 (5), 1983-1989 (2004).</li><li>Yang, H., Chen, D. Z., 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>Huang, Y. B., Fu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrolysis+of+cellulose+to+glucose+by+solid+acid+catalysts.">Hydrolysis of cellulose to glucose by solid acid catalysts.</a> Green Chem. 15 (5), 1095-1111 (2013).</li><li>Shimizu, K. I., Satsuma, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+a+rational+control+of+solid+acid+catalysis+for+green+synthesis+and+biomass+conversion.">Toward a rational control of solid acid catalysis for green synthesis and biomass conversion.</a> Energy &amp; Environ Sci. 4 (9), 3140-3153 (2011).</li><li>Wang, Q. Q., Zhu, J. Y., Considine, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strong+and+optically+transparent+films+prepared+using+cellulosic+solid+residue+(CSR)+recovered+from+cellulose+nanocrystals+(CNC)+production+waste+stream.">Strong and optically transparent films prepared using cellulosic solid residue (CSR) recovered from cellulose nanocrystals (CNC) production waste stream.</a> ACS Appl Mater Interfaces. 5 (7), 2527-2534 (2013).</li><li>Chen, L. H., Zhu, J. Y., Baez, C., Kitin, P., Elder, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+thermal-stable+and+functional+cellulose+nanocrystals+and+nanofibrils+produced+using+fully+recyclable+organic+acids.">Highly thermal-stable and functional cellulose nanocrystals and nanofibrils produced using fully recyclable organic acids.</a> Green Chem. 18, 3835-3843 (2016).</li><li>Fischer, E., Speier, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Darstellungder+der+Ester.">Darstellungder der Ester.</a> Chemische Berichte. 28 (3), 3252-3258 (1895).</li><li>Allen, T. C., Cuculo, J. 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+derivatives+containing+carboxylic+acid+groups.">Cellulose derivatives containing carboxylic acid groups.</a> J Polym Sci: Macromol Rev. 7 (1), 189-262 (1973).</li><li>Wang, Q. Q., Zhao, X. B., Zhu, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetics+of+strong+acid+hydrolysis+of+a+bleached+kraft+pulp+for+producing+cellulose+nanocrystals+(CNCs).">Kinetics of strong acid hydrolysis of a bleached kraft pulp for producing cellulose nanocrystals (CNCs).</a> Ind Eng Chem Res. 53 (27), 11007-11014 (2014).</li><li>Segal, L., Creely, J. J., Martin, A. E., Conrad, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+empirical+method+for+estimating+the+degree+of+crystallinity+of+native+cellulose+using+the+X-ray+diffractometer.">An empirical method for estimating the degree of crystallinity of native cellulose using the X-ray diffractometer.</a> Text Res J. 29 (10), 786-794 (1959).</li></ol>

陈和朱是使用CNC和CNF生产二元酸的美国专利申请的共同发明人。

从马来酸水解数控样品的较厚数控直径导致了中等平均纵横比7.24和8.53，对于CNC控制器从分别的BEP和UMHP，尽管它们的长的长度，如上所述。所述的CNFs具有比各自的CNC较长的长度和更薄的直径，这就造成了13.9和19.0纵横比大，为的CNC从分别的BEP和UMHP，都大得多。它可以使用剧烈的机械原纤化，以减少CNF直径来提高宽高比如在本研究中微流化所用的压力是相当低的。 木质素颗粒?...

经济的可持续发展，不仅需要使用的是可再生和可生物降解原料，但也使用绿色环保的制造技术，生产出各种从这些可再生原料的生物制品和生化的。纤维素纳米材料，如纤维素纳米晶体（CNC）和纤维素纳米原纤维（CNF），从可再生的木质纤维素生产可生物降解的和具有适于显影的范围内的生物制品1,2的独特的机械和光学性能。不幸的是，用于制造纤维素纳米材料的现有技术或者是能量密集型的使用纯机械开纤或环境不可持续由于非回收或处理的化学品，回收不足时，例如使用浓无机酸水解过程3-8或氧化方法9-当如11。此外，氧化的方法也可以产生对环境有毒的COMPO与木质纤维素反应unds。因此，发展绿色制造技术用于生产纤维素纳米材料是非常重要的，充分利用丰富的和可再生的材料 - 木质纤维素。 用酸水解，溶解半纤维素和解聚纤维素是用于制造纤维素纳米材料的有效途径。固体酸已被用于糖产量从纤维素与缓和酸回收12,13的优点。用浓无机酸以前的研究表明，低级酸浓度提高数控收率和结晶3,5。这表明，强酸可能损坏纤维素结晶而温和的酸水解可能是通过综合生产和数控与CNF 3,14的办法提高了性能和纤维素纳米材料的产量。在这里，我们使用浓度固体二元酸水解全国生产记录的方法ËCNC与CNF 15一起。这些二羧酸具有在低温或环境温度下的溶解度低，因此，它们可通过成熟结晶技术很容易地回收。它们也具有在高温下便于浓酸水解未经煮沸或使用压力容器良好的溶解性。因为这些酸也有较高的pKa比用于数控生产典型的无机酸，它们的使用效果良好的数控结晶度，尽管低级数控产率，与纤维状的纤维素固体残余物的显着量（FCSR或部分水解的纤维）剩余由于不完整的纤维素解聚。该FCSR可使用低能量输入，通过后续的机械开纤生产CNF。因此，与使用无机酸纤维素损失为糖是最小的。 它公知的是羧酸可以通过费- Speier酯化16酯化纤维素。施加二羧酸与纤维素可导致半酸未交联的酯17（或羧化），以产生羧基化CNC和CNF为我们证实15先前。这里介绍的方法可以产生羧基和热稳定CNF和数控，这也是无论从漂白或未漂白纸浆高度结晶，同时具有相对简单和高化学品回收和使用低能源投入。

<table><tbody><tr><td>Bleached eucalypus pulp&amp;nbsp;</td><td>Aracruz Cellulose</td><td></td><td></td></tr><tr><td>Unbleached mixed hardwood kraft pulp&amp;nbsp;</td><td>International Paper&amp;nbsp;</td><td></td><td></td></tr><tr><td>Maleic acid</td><td>Sigma-Aldrich</td><td>M0375-1KG/CAS110-16-7</td><td>Powder; assay: 99.0% (HPLC)</td></tr><tr><td>Glycerol</td><td>Sigma-Aldrich</td><td>G5516-4L/CAS56-81-5</td><td></td></tr><tr><td>Sodium hydroxide</td><td>Fisher Scientific</td><td>S318-500/CAS1310-73-2, 497-19-8</td><td>Certified ACS</td></tr><tr><td>Sodium chloride</td><td>Mallinckrodt</td><td>7581-12/CAS7647-14-5</td><td>Crystal,AR</td></tr><tr><td>Cupriethylenediamine solution</td><td>GFS Chemicals</td><td>E32103-1L/CAS14552-35-3</td><td>1 M, for determination of solution viscosity of pulps</td></tr><tr><td>Acetone</td><td>Fisher Scientific</td><td>A18-500/CAS67-64-1</td><td>Certified ACS</td></tr><tr><td>Accu-Test&lt;sup&gt;TM&lt;/sup&gt; Vials for COD Testing</td><td>Bioscience,Inc.</td><td>01-215-28</td><td>COD testing for 20 to 900&amp;nbsp;mg/L standard range concentration</td></tr><tr><td>Heating plate</td><td>IKA</td><td></td><td>Mode: C-MAD HS7 digital</td></tr><tr><td>Magnetic stir bar</td><td>ACE Glass</td><td></td><td></td></tr><tr><td>Pyrex three-neck round-bottom flask</td><td>Sigma-Aldrich</td><td>CLS4965B500-1EA</td><td></td></tr><tr><td>Dialysis tubing cellulose membrane</td><td>Sigma-Aldrich</td><td>D9402-100FT</td><td>Typical molecular weight cut-off = 14,000 kDa</td></tr><tr><td>Disposable aluminum dishes</td><td>Sigma-Aldrich</td><td>Z154857-1PAK</td><td>Circles, 60 mm</td></tr><tr><td>Disintegrator</td><td>Testing Machines Inc.(TMI)</td><td></td><td></td></tr><tr><td>Microfluidizer</td><td>Microfluidics Corporation</td><td></td><td></td></tr><tr><td>Sonicator</td><td>Qsonica LLC.</td><td></td><td>Mode: 3510R-MT, 50-60&amp;nbsp;Hz, 180&amp;nbsp;W</td></tr><tr><td>Zeta potential analyzer</td><td>Brookhaven Instruments Corporation</td><td></td><td></td></tr><tr><td>FTIR</td><td>PerkinElmer</td><td></td><td></td></tr><tr><td>Conductometric titrator</td><td>Yellow Springs Instrument (YSI)</td><td></td><td></td></tr><tr><td>TGA analyzer</td><td>PerkinElmer</td><td></td><td></td></tr><tr><td>X-ray diffractometer</td><td>Bruker Corporation</td><td></td><td></td></tr><tr><td>AFM imging&amp;nbsp;</td><td>AFM Workshop</td><td></td><td></td></tr><tr><td>SEM imaging</td><td>Carl Zeiss</td><td></td><td></td></tr></tbody></table>

green and low-cost production of thermally stable and carboxylated cellulose nanocrystals and nanofibrils using highly recyclable dicarboxylic acids

这里，我们证明成本潜在的低使用高度可回收的二固体酸的漂白桉木浆（BEP）和未漂白混合阔叶牛皮浆（UMHP）纤维高的热稳定性和羧基化纤维素纳米晶（CNC控制器）和纳米原纤维（CNF）的绿色生产。典型的操作条件为50的酸浓度 - 70％（重量）在100℃下60分钟和120分钟120℃（在大气压下没有沸点），对BEP和UMHP分别。所得的CNC具有较高的热降解温度比其相应的原料纤维和羧酸基含量为0.2 - 0.4毫摩尔/克。低强度（1.0高pKa值 - 3.0）有机酸也导致约为239两种长度更长的CNC - 336纳米和更高的结晶度比使用的CNC无机酸产生的。纤维素损失糖是最小的。从二羧酸水解纤维状的纤维素固体残余物（FCSR）被用来通过与低能量输入随后的机械颤动产生羧基化的CNFs。

与进料酸水解纤维对应SEM图像沿着从BEP和UMHP CNC和CNF的典型的AFM图像示于图1和2。该图像清楚地表明在纤维长度的大幅度减少通过酸水解，在纤维直径变化最小（ 图1a与1b中的比较，以及图2a与2b）的 。缩短的纤维长度也被聚合的水解纤维的测量纤维素度（DP）的反射。 DP分别降低从1021和806至319和342，对于BEP和UMHP。与典型?...

Watch this Scientific Journal Video about Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids at JoVE.c

Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids

在这里，我们证明了使用高度可回收固体二羧酸高度热稳定的和羧化的纤维素纳米晶体（CNC）和纳米原纤维（CNF）的绿色和可持续的生产的新方法。

热稳定和羧基化纤维素纳米晶和纳米原纤维使用高度可回收的二元羧酸绿色和低成本生产

Here we demonstrate potentially low cost and green productions of high thermally stable and carboxylated cellulose nanocrystals (CNCs) and nanofibrils ...

green-low-cost-production-thermally-stable-carboxylated-cellulose

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

11.8K 次观看.  Nanjing Forestry University. 在这里，我们证明了使用高度可回收固体二羧酸高度热稳定的和羧化的纤维素纳米晶体（CNC）和纳米原纤维（CNF）的绿色和可持续的生产的新方法。 

视频: Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids

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

Pretreatment of Lignocellulosic Biomass with Low-cost Ionic Liquids

A number of ionic liquids (ILs) with economically attractive production costs have recently received growing interest as media for the delignification of a variety of lignocellulosic feedstocks. Here we demonstrate the use of these low-cost protic ILs in the deconstruction of lignocellulosic biomass (Ionosolv pretreatment), yielding cellulose and a purified lignin. In the most generic process, the protic ionic liquid is synthesized by accurate combination of aqueous acid and amine base. The water content is adjusted subsequently. For the delignification, the biomass is placed into a vessel with IL solution at elevated temperatures to dissolve the lignin and hemicellulose, leaving a cellulose-rich pulp ready for saccharification (hydrolysis to fermentable sugars). The lignin is later precipitated from the IL by the addition of water and recovered as a solid. The removal of the added water regenerates the ionic liquid, which can be reused multiple times. This protocol is useful to investigate the significant potential of protic ILs for use in commercial biomass pretreatment/lignin fractionation for producing biofuels or renewable chemicals and materials.

The pretreatment of lignocellulosic biomass with protic low-cost ionic liquids is shown, resulting in a delignified cellulose-rich pulp and a purified lignin. The pulp gives rise to high glucose yields after enzymatic saccharification.

木质纤维素生物质预处理低成本离子液体

A number of ionic liquids (ILs) with economically attractive production costs have recently received growing interest as media for the delignification of ...

环境科学

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

Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While metal-based nanoparticles are associated with synthetic and environmental hassles, cellulose introduces a green, sustainable alternative for nanoparticle synthesis. Here, we present the chemical synthesis and separation procedures to produce new classes of hairy nanoparticles (bearing both amorphous and crystalline regions) and biopolymers based on wood fibers. Through periodate oxidation of soft wood pulp, the glucose ring of cellulose is opened at the C2-C3 bond to form 2,3-dialdehyde groups. Further heating of the partially oxidized fibers (e.g., T = 80 &#176;C) results in three products, namely fibrous oxidized cellulose, sterically stabilized nanocrystalline cellulose (SNCC), and dissolved dialdehyde modified cellulose (DAMC), which are well separated by intermittent centrifugation and co-solvent addition. The partially oxidized fibers (without heating) were used as a highly reactive intermediate to react with chlorite for converting almost all aldehyde to carboxyl groups. Co-solvent precipitation and centrifugation resulted in electrosterically stabilized nanocrystalline cellulose (ENCC) and dicarboxylated cellulose (DCC). The aldehyde content of SNCC and consequently surface charge of ENCC (carboxyl content) were precisely controlled by controlling the periodate oxidation reaction time, resulting in highly stable nanoparticles bearing more than 7 mmol functional groups per gram of nanoparticles (e.g., as compared to conventional NCC bearing &#60;&#60; 1 mmol functional group/g). Atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) attested to the rod-like morphology. Conductometric titration, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), electrokinetic-sonic-amplitude (ESA) and acoustic attenuation spectroscopy shed light on the superior properties of these nanomaterials.

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 ...

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

Estimation of Crystalline Cellulose Content of Plant Biomass using the Updegraff Method

Cellulose is the most abundant polymer on Earth generated by photosynthesis and the main load-bearing component of cell walls. The cell wall plays a significant role in plant growth and development by providing strength, rigidity, rate and direction of cell growth, cell shape maintenance, and protection from biotic and abiotic stressors. The cell wall is primarily composed of cellulose, lignin, hemicellulose and pectin. Recently plant cell walls have been targeted for the second-generation biofuel and bioenergy production. Specifically, the cellulose component of the plant cell wall is used for the production of cellulosic ethanol. Estimation of cellulose content of biomass is critical for fundamental and applied cell wall research. The Updegraff method is simple, robust, and the most widely used method for the estimation of crystalline cellulose content of plant biomass. The alcohol insoluble crude cell wall fraction upon treatment with Updegraff reagent eliminates the hemicellulose and lignin fractions. Later, the Updegraff reagent resistant cellulose fraction is subjected to sulfuric acid treatment to hydrolyze the cellulose homopolymer into monomeric glucose units. A regression line is developed using various concentrations of glucose and used to estimate the amount of the glucose released upon cellulose hydrolysis in the experimental samples. Finally, the cellulose content is estimated based on the amount of glucose monomers by colorimetric anthrone assay.

The Updegraff method is the most widely used method for the cellulose estimation. The main purpose of this demonstration is to provide a detailed Updegraff protocol for estimation of cellulose content in plant biomass samples.

使用上格拉夫方法估计植物生物质的晶体纤维素含量

Cellulose is the most abundant polymer on Earth generated by photosynthesis and the main load-bearing component of cell walls. The cell wall plays a ...

Synthesis Method for Cellulose Nanofiber Biotemplated Palladium Composite Aerogels

Here, a method to synthesize cellulose nanofiber biotemplated palladium composite aerogels is presented. Noble metal aerogel synthesis methods often result in fragile aerogels with poor shape control. The use of carboxymethylated cellulose nanofibers (CNFs) to form a covalently bonded hydrogel allows for the reduction of metal ions such as palladium on the CNFs with control over both nanostructure and macroscopic aerogel monolith shape after supercritical drying. Crosslinking the carboxymethylated cellulose nanofibers is achieved using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) in the presence of ethylenediamine. The CNF hydrogels maintain their shape throughout synthesis steps including covalent crosslinking, equilibration with precursor ions, metal reduction with high concentration reducing agent, rinsing in water, ethanol solvent exchange, and CO2 supercritical drying. Varying the precursor palladium ion concentration allows for control over the metal content in the final aerogel composite through a direct ion chemical reduction rather than relying on the relatively slow coalescence of pre-formed nanoparticles used in other sol-gel techniques. With diffusion as the basis to introduce and remove chemical species into and out of the hydrogel, this method is suitable for smaller bulk geometries and thin films. Characterization of the cellulose nanofiber-palladium composite aerogels with scanning electron microscopy, X-ray diffractometry, thermal gravimetric analysis, nitrogen gas adsorption, electrochemical impedance spectroscopy, and cyclic voltammetry indicates a high surface area, metallized palladium porous structure.

A synthesis method for cellulose nanofiber biotemplated palladium composite aerogels is presented.The resulting composite aerogel materials offer potential for catalysis, sensing, and hydrogen gas storage applications.

纤维素纳米纤维生物模板复合气凝胶的合成方法

Here, a method to synthesize cellulose nanofiber biotemplated palladium composite aerogels is presented. Noble metal aerogel synthesis methods often ...

Fractionation of Lignocellulosic Biomass using the OrganoCat Process

The shift from a petroleum-based to a more sustainable and bio-based economy requires the development of new refinery concepts to maintain the supply of raw materials and energy. For these novel and sustainable biorefinery concepts, it is important to use catalysts and solvents that are aligned with the principles of Green Chemistry. Therefore, the implementation of biogenic alternatives can be a promising solution. The lignocellulose pretreatment and fractionation process presented herein-OrganoCat-is an integrated fractionation of lignocellulose into its main components using biogenic acids such as 2,5-furandicarboxylic acid as catalyst. Hemicelluloses and other non-cellulosic polysaccharides are selectively depolymerized by the diluted acid and dissolved, while the crystalline cellulose remains in the solid pulp. In the presence of a second organic phase consisting of biogenic 2-methyltetrahydrofuran, disentangled lignin is extracted in situ. The process allows for the efficient fractionation of the three main components-lignin, cellulose, and non-cellulosic sugars. This helps to focus on the quality of the lignin, the improvement of enzymatic hydrolysis of the cellulose-enriched pulp, and the mild non-cellulosic sugar extraction with low degradation.

OrganoCat is a method for the pretreatment and fractionation of lignocellulose under mild conditions into lignin, fermentable sugars, and cellulose pulp. In a biogenic, biphasic solvent system of water and 2-methyltetrahydrofuran with 2,5-furancarboxylic acid as catalyst, the OrganoCat products are separated in situ for straightforward product recovery.

使用有机催化工艺分馏木质纤维素生物质

The shift from a petroleum-based to a more sustainable and bio-based economy requires the development of new refinery concepts to maintain the supply of ...

Bacterial Cellulose Spheres that Encapsulate Solid Materials

Bacterial cellulose (BC) spheres have been increasingly researched since the popularization of BC as a novel material. This protocol presents an affordable and simple method for BC sphere production. In addition to producing these spheres, an encapsulation method for solid particles has also been identified. To produce BC spheres, water, black tea, sugar, vinegar, and bacterial culture are combined in a baffled flask and the contents are agitated. After determining the proper culture conditions for BC sphere formation, their ability to encapsulate solid particles was tested using biochar, polymer beads, and mine waste. Spheres were characterized using ImageJ software and thermal gravimetric analysis (TGA). Results indicate that spheres with 7.5 mm diameters can be made in 7 days. Adding various particles increases the average size range of the BC capsules. The spheres encapsulated 10 - 20% of their dry mass. This method shows low-cost sphere production and encapsulation that is possible with easily obtainable materials. BC spheres may be used in the future as a contaminant removal aid, controlled release fertilizer coating, or soil amendment.

This protocol presents an easy, inexpensive method of forming bacterial cellulose (BC) spheres. This biomaterial can function as an encapsulation medium for solid materials, including biochar, polymer spheres, and mine waste.

封装固体材料的细菌纤维素球体

Bacterial cellulose (BC) spheres have been increasingly researched since the popularization of BC as a novel material. This protocol presents an ...

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 ...