不同生长期毛竹材细胞壁力学性能与微纤丝角
|
摘要
【目的】以不同生长期的毛竹材纤维细胞壁为研究重点,在纳米尺度下分别表征不同竹龄毛竹材纤维细胞壁的结构特征和力学性能,阐明成熟毛竹材纤维细胞壁的结构特征和力学性能与幼龄竹和过熟竹的差异,为竹材的科学采伐和竹材分级、改性及重组研究与合理利用提供理论依据。【方法】采用滑走显微制片法观察毛竹材横切面显微结构并精准确定其纳米压痕测试部位,应用纳米压痕技术结合非包埋制样法对0.5年幼龄毛竹、4.5年成熟毛竹和10.5年过熟毛竹材纤维细胞壁力学性能进行研究;利用广角X-射线散射法结合高斯拟合算法对不同竹龄毛竹材纤维细胞壁的微纤丝角进行测算。【结果】毛竹材竹肉横切面显微结构表明,毛竹主要由薄壁组织细胞和维管束组成,维管束由导管和包裹着导管周围的厚壁纤维细胞组成;对其厚壁纤维细胞壁的纳米压痕测试结果表明,3个生长发育期的毛竹材细胞壁力学性能指标有较大不同,其中0.5年幼龄毛竹材的细胞壁弹性模量和硬度最小,分别为10.7 GPa和0.358 GPa,4.5年成熟毛竹材的细胞壁弹性模量和硬度均为最大,分别为19.6 GPa和0.498 GPa,10.5年过熟毛竹材的细胞壁硬度和弹性模量居二者之间,分别为17.6 GPa和0.445 GPa;微纤丝角测试结果同样表明不同生长发育期毛竹材细胞壁的微纤丝角不同,其中0.5年幼龄毛竹材微纤丝角最大,为13.5°,4.5年成熟毛竹材微纤丝角度最小,为8.43°,而10.5年过熟毛竹材微纤丝角介于二者之间,为11.9°。【结论】生长期对毛竹材纤维细胞壁力学性能和微纤丝排列均有影响,幼龄毛竹材纤维细胞壁力学性能与成熟毛竹材纤维细胞壁力学性能有较大差别,随着竹龄增大达到成熟期时,毛竹材纤维细胞壁力学性能达到最大,但毛竹材并不是生长期越长其细胞壁力学性能越好,而是随着竹材老化其力学性能呈下降状态。处于成熟期的毛竹材其纤维细胞壁微纤丝排列与主轴的夹角呈较小状态,也决定了其具有较优的力学性能。依据3个竹龄毛竹材纤维细胞壁力学性能和微纤丝角测量结果,本研究在细胞壁水平阐明了毛竹材在成熟期时其微观力学性能优于幼龄毛竹材和过熟毛竹材。
【Objective】 Bamboo age is a key factor for logging and utilization of bamboo,and hence we focused on the fiber cell wall of different growth period. The characteristic and mechanical performance of fiber cell wall of moso bamboo aged 0. 5 a,4. 5 a,and 10. 5 a were investigated to find out the differences of characteristic and mechanical performance among immature,mature and overmature moso bamboo at nano-scale,which provided a new theoretical basis for the research of scientific logging,classification,modification and reorganization and rational utilization of bamboo in the future.【Method】 The sections made by microtome and ultramicrotome were used to observe microstructure of the crosssection and then choose the precise area for nanoindentation experiments. Nanoindentation experiment combined with nonembedding method was used to investigate the mechanical properties of fiber cell wall,and the wide-angle X-ray scattering method with the Gaussian quasi legitimate calculation was applied to obtain the value of micrfibiril angle of moso bamboo.【Result】 The observation of cross-section indicated that the parenchyma cells and vascular bundles were the maincomponents of moso bamboo,and the vascular bundle was consisted of the vessel and thick walled fiber cells that surrounded the vessels. The mechanical properties of moso bamboo fiber exhibated significant differences among different growth period. The nanoindentation result showed that the mechanical properties of immature moso bamboo fiber cell wall were lower than those of mature and overimature moso bamboo. The value of elastic modulus and hardness were 10. 7 GPa and 0. 358 GPa,respectively. The mature moso bamboo showed the highest elastic modulus and hardness,19. 6 GPa and0. 489 GPa. The elastic modulus and hardness of overmature moso bamboo were 17. 6 GPa and 0. 445 GPa,respectively.The microfibril angle tests indicated that they were diverse among bamboos in different growth period. The mean microfibril angle of 0. 5 a immature moso bamboo with 13. 5° is higher than the others,and the 4. 5 a mature moso bamboo with8. 43° is lowest,while the miscrofibril angle of 10. 5 a overmature moso bamboo is 11. 9°. 【Conclusion】 Based on the result it was concluded that the growth period have an influence on the fiber cell wall mechanical properties and microfibril angle of moso bamboo. The micromechanical properties showed apparent differences between the immature and mature moso bamboo,it was enhanced with bamboo age and achieved optimal micromechanical performances at mature,however,the reduced elastic modulus and hardness slightly decreased with bamboo age after the maturity. The angle between the microfibril arrangements and cell axis was least when the moso bamboo was mature,which account for its better mechanical properties. As a consequently,this study illustrates the micromechanical properties of the 4-5 years old moso bamboo was better than that of the immature and overmature moso bamboo at cell wall level.
【Objective】 Bamboo age is a key factor for logging and utilization of bamboo,and hence we focused on the fiber cell wall of different growth period. The characteristic and mechanical performance of fiber cell wall of moso bamboo aged 0. 5 a,4. 5 a,and 10. 5 a were investigated to find out the differences of characteristic and mechanical performance among immature,mature and overmature moso bamboo at nano-scale,which provided a new theoretical basis for the research of scientific logging,classification,modification and reorganization and rational utilization of bamboo in the future.【Method】 The sections made by microtome and ultramicrotome were used to observe microstructure of the crosssection and then choose the precise area for nanoindentation experiments. Nanoindentation experiment combined with nonembedding method was used to investigate the mechanical properties of fiber cell wall,and the wide-angle X-ray scattering method with the Gaussian quasi legitimate calculation was applied to obtain the value of micrfibiril angle of moso bamboo.【Result】 The observation of cross-section indicated that the parenchyma cells and vascular bundles were the maincomponents of moso bamboo,and the vascular bundle was consisted of the vessel and thick walled fiber cells that surrounded the vessels. The mechanical properties of moso bamboo fiber exhibated significant differences among different growth period. The nanoindentation result showed that the mechanical properties of immature moso bamboo fiber cell wall were lower than those of mature and overimature moso bamboo. The value of elastic modulus and hardness were 10. 7 GPa and 0. 358 GPa,respectively. The mature moso bamboo showed the highest elastic modulus and hardness,19. 6 GPa and0. 489 GPa. The elastic modulus and hardness of overmature moso bamboo were 17. 6 GPa and 0. 445 GPa,respectively.The microfibril angle tests indicated that they were diverse among bamboos in different growth period. The mean microfibril angle of 0. 5 a immature moso bamboo with 13. 5° is higher than the others,and the 4. 5 a mature moso bamboo with8. 43° is lowest,while the miscrofibril angle of 10. 5 a overmature moso bamboo is 11. 9°. 【Conclusion】 Based on the result it was concluded that the growth period have an influence on the fiber cell wall mechanical properties and microfibril angle of moso bamboo. The micromechanical properties showed apparent differences between the immature and mature moso bamboo,it was enhanced with bamboo age and achieved optimal micromechanical performances at mature,however,the reduced elastic modulus and hardness slightly decreased with bamboo age after the maturity. The angle between the microfibril arrangements and cell axis was least when the moso bamboo was mature,which account for its better mechanical properties. As a consequently,this study illustrates the micromechanical properties of the 4-5 years old moso bamboo was better than that of the immature and overmature moso bamboo at cell wall level.
引文
房桂干,王菊华,任维羡,等.1989.毛竹的形态学特性、超微结构及木素分布.中国造纸学报,1(4):42-49.(Fang G G,Wang J H,Ren W X,et al.1989.A study on the morphology,ultrastructure and lignin distribution of bamboo.Transaction of China Pulp and Paper,1(4):42-49.[in Chinese])
关明杰,朱一辛,莫弦丰,等.2010.毛竹材质老化过程中几个基本性质变化与建筑原竹的选择.西南大学学报:自然科学版,32(1):144-147.(Guan M J,Zhu Y X,Mo X F,et al.2010.The variety during aging process of bamboo and the selection of raw bamboo for construction.Journal of Southwest University(Natural Science Edition),32(1):144-147.[in Chinese])
江泽慧.2002.世界竹藤.沈阳:辽宁科学出版社.(Jiang Z H.2002.World bamboo and rattan.Shenyang:Liaoning Science and Technology Press.[in Chinese])
马灵飞,马乃训.1997.毛竹材材性变异的研究.林业科学,33(4):356-364.(Ma L F,Ma N X.1997.Study on the variation of wood properties of bamboo.Scientia Silvae Sinicae,33(4):356-364.[in Chinese])
王传贵,江泽慧,费本华,等.2012.化学成分对木材细胞壁纵向弹性模量和硬度的影响.北京林业大学学报,34(3):107-110.(Wang C G,Jiang Z H,Fei B H,et al.2012.Effects of chemical components on longitudinal MOE and hardness of wood cell wall.Journal of Beijing Forestry University,34(3):107-110.[in Chinese])
阮锡根,尹思慈,孙成志.1982.应用X射线衍射-(002)衍射弧法-测定木材纤维次生壁的微纤丝角.林业科学,18(1):64-71.(Ruan X G,Yin S C,Sun C Z.1982.Using the X-ray diffraction(002)to determine the microfibril angle of the secondary wall of wood fiber.Scientia Silvae Sinicae,18(1):64-71.[in Chinese])
俞友明,金永明,於琼华,等.2004.雷竹竹材物理力学性质变异规律的研究.竹子研究汇刊,23(2):50-54.(Yu Y M,Jin Y M,Yu Q H,et al.2004.A study on the varistion pattern of physical-mechanical properties of Phyllostachys praecox wood.Journal of Bamboo Research,23(2):50-54.[in Chinese])
俞友明,方伟,林新春,等.2005.苦竹竹材物理力学性能的研究.西南林学院学报,25(3):64-67.(Yu Y M,Fang W,Lin X C,et al.2005.Study on physical and mechanical properties of bamboo(Pleioblastus amarus).Journal of Southwest Forestry College,25(3):64-67.[in Chinese])
周芳纯.1991.竹材的力学性质.竹类研究,(1):45-57.(Zhou F C.1991.Mechanical properties of bamboo.Bamboo Research,(1):45-57.[in Chinese])
张齐生.1995.竹材工业化利用.北京:中国林业出版社.(Zhang Q S.1995.The industrial utilization of bamboo.Beijing:Chinese Forestry Publishing House.[in Chinese])
张齐生,关明杰,纪文兰.2002.毛竹材质生成过程中化学成分的变化.南京林业大学学报:自然科学版,26(2):7-10.(Zhang Q S,Guan M J,Ji W L.2002.Variation of moso bamboo chemical compositions during mature growing period.Journal of Nanjing Forestry University:Natural Science Edition,26(2):7-10.[in Chinese])
Andersson S,Serimaa R,Torkkeli M,et al.2000.Microfibril angle on Norway spruce(Picea abies(L.)Karst.)compression wood:comparison of measuring techniques.Journal of Wood Science,46:343-349.
Andersson S.2006.A study of the nanostructure of the cell wall of the tracheids of conifer xylem by X-ray scattering.Ph D Thesis of University of Helsinki.
Barnett J R,Bonham V A.2004.Cellulose microfibril angle in the cell wall of wood fibers.Biological Reviews,79(2):461-472.
Cave I D,Walker J C F.1994.Stiffness of wood in fast-grown plantation softwoods:the influence of microfibril angle.Forest Products Journal,44(5):43-48.
Donaldsom L.2008.Microfibril angle:measurement,variation and relationships:a review.IAWA,29(4):345-386.
Gindl W,Sch9berl T.2004.The significance of the elastic modulus of wood cell walls obtained from nanoindentation measurements.Composites Part A:Applied Science and Manufacturing,35(11):1345-1349.
Huang Y H,Fei B H,Yu Y,et al.2012.Plant age effect on mechanical propweties of moso bamboo(Phyllostachys heterocycle var.pubescens)single fibers.Wood and Fiber Science,44(2):196-201.
Joger A,Bader T,Hofstetter K,et al.2011.The relation between indentation modulus,microfibril angle,and elastic properties of wood cell walls.Composites Part A Applied Science&Manufacturing,42(6):677-685.
Meng Y J,Wang S Q,Cai Z Y,et al.2013.A novel sample preparation method to avoid influence of embedding medium during nanoindentation.Applied Physics A,110(2):361-369.
Oliver W C,Pharr G M.1992.An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments.Journal of Materials Research,7(6):1564-1583.
Tze W T Y,Wang S Q,Rials T G,et al.2007.Nanoindentation of wood cell walls:continuous stiffness and hardness measurements.Composite:Part A:Applied Science and Manufacturing,38(3):945-953.
Wang S,Lee S H,Tze W T Y,et al.2006.Nanoindentation as a tool for understanding nano-mechanical properties of wood cell wall and biocomposites.International Conference on Nanotechnology.
Wang X Q,Li X Z,Ren H Q.2010.Variation of microfibril angle and density in moso bamboo(Phyllostachys Pubescens).Journal of Tropical Forest Science,22(1):88-96.
Wang Y R,Leppnen K,Andersson S,et al.2012.Studies on the nanostructure of the cell wall of bamboo using X-ray scattering.Wood Sci Technol,46(1/3):317-332.
Wang H K,An X J,Li W J,et al.2014.Variation of mechanical properties of single bamboo fibers(Dendrocalamus latiflorus Munro)with respect to age and location in culms.Holzforschung,68(3):291-297.
Wang Y R,Liu C W,Zhao R J,et al.2016.Anatomical characteristics,microfibril angle and micromechanical properties of cottonwood(Populus deltoides)and its hybrids.Biomass and Bioenergy,93:72-77.
Yang S M,Jiang Z H,Ren H Q,et al.2009.Variations of the microfibril angle in developmental moso bamboo culms.Journal of Nanjing Forestry University,33(5):73-76.
Yu Y,Fei B,Zhang B,et al.2007.Cell-wall mechanical properties of bamboo investigated by in-situ imaging nanoindentation.Wood and Fiber Science,39(4):527-535.
Yu Y,Tian G L,Wang H K,et al.2011.Mechanical characterization of single bamboo fibers with nanoindentation and microtensile technique.Holzforschung,65(1):113-119.
Zou L H,Jin H,Lu W Y,et al.2009.Nanoscale structural and mechanical characterization of the cell wall of bamboo fibers.Materials Science and Engineering:C,29(4):1375-1379.
Zhao R J,Yao C L,Cheng X W,et al.2014.Anatomical,chemical and mechanical properties of fast-growing Populus×euramericana cv.‘74/76’.IAWAI Journal,35(3):158-169.
关明杰,朱一辛,莫弦丰,等.2010.毛竹材质老化过程中几个基本性质变化与建筑原竹的选择.西南大学学报:自然科学版,32(1):144-147.(Guan M J,Zhu Y X,Mo X F,et al.2010.The variety during aging process of bamboo and the selection of raw bamboo for construction.Journal of Southwest University(Natural Science Edition),32(1):144-147.[in Chinese])
江泽慧.2002.世界竹藤.沈阳:辽宁科学出版社.(Jiang Z H.2002.World bamboo and rattan.Shenyang:Liaoning Science and Technology Press.[in Chinese])
马灵飞,马乃训.1997.毛竹材材性变异的研究.林业科学,33(4):356-364.(Ma L F,Ma N X.1997.Study on the variation of wood properties of bamboo.Scientia Silvae Sinicae,33(4):356-364.[in Chinese])
王传贵,江泽慧,费本华,等.2012.化学成分对木材细胞壁纵向弹性模量和硬度的影响.北京林业大学学报,34(3):107-110.(Wang C G,Jiang Z H,Fei B H,et al.2012.Effects of chemical components on longitudinal MOE and hardness of wood cell wall.Journal of Beijing Forestry University,34(3):107-110.[in Chinese])
阮锡根,尹思慈,孙成志.1982.应用X射线衍射-(002)衍射弧法-测定木材纤维次生壁的微纤丝角.林业科学,18(1):64-71.(Ruan X G,Yin S C,Sun C Z.1982.Using the X-ray diffraction(002)to determine the microfibril angle of the secondary wall of wood fiber.Scientia Silvae Sinicae,18(1):64-71.[in Chinese])
俞友明,金永明,於琼华,等.2004.雷竹竹材物理力学性质变异规律的研究.竹子研究汇刊,23(2):50-54.(Yu Y M,Jin Y M,Yu Q H,et al.2004.A study on the varistion pattern of physical-mechanical properties of Phyllostachys praecox wood.Journal of Bamboo Research,23(2):50-54.[in Chinese])
俞友明,方伟,林新春,等.2005.苦竹竹材物理力学性能的研究.西南林学院学报,25(3):64-67.(Yu Y M,Fang W,Lin X C,et al.2005.Study on physical and mechanical properties of bamboo(Pleioblastus amarus).Journal of Southwest Forestry College,25(3):64-67.[in Chinese])
周芳纯.1991.竹材的力学性质.竹类研究,(1):45-57.(Zhou F C.1991.Mechanical properties of bamboo.Bamboo Research,(1):45-57.[in Chinese])
张齐生.1995.竹材工业化利用.北京:中国林业出版社.(Zhang Q S.1995.The industrial utilization of bamboo.Beijing:Chinese Forestry Publishing House.[in Chinese])
张齐生,关明杰,纪文兰.2002.毛竹材质生成过程中化学成分的变化.南京林业大学学报:自然科学版,26(2):7-10.(Zhang Q S,Guan M J,Ji W L.2002.Variation of moso bamboo chemical compositions during mature growing period.Journal of Nanjing Forestry University:Natural Science Edition,26(2):7-10.[in Chinese])
Andersson S,Serimaa R,Torkkeli M,et al.2000.Microfibril angle on Norway spruce(Picea abies(L.)Karst.)compression wood:comparison of measuring techniques.Journal of Wood Science,46:343-349.
Andersson S.2006.A study of the nanostructure of the cell wall of the tracheids of conifer xylem by X-ray scattering.Ph D Thesis of University of Helsinki.
Barnett J R,Bonham V A.2004.Cellulose microfibril angle in the cell wall of wood fibers.Biological Reviews,79(2):461-472.
Cave I D,Walker J C F.1994.Stiffness of wood in fast-grown plantation softwoods:the influence of microfibril angle.Forest Products Journal,44(5):43-48.
Donaldsom L.2008.Microfibril angle:measurement,variation and relationships:a review.IAWA,29(4):345-386.
Gindl W,Sch9berl T.2004.The significance of the elastic modulus of wood cell walls obtained from nanoindentation measurements.Composites Part A:Applied Science and Manufacturing,35(11):1345-1349.
Huang Y H,Fei B H,Yu Y,et al.2012.Plant age effect on mechanical propweties of moso bamboo(Phyllostachys heterocycle var.pubescens)single fibers.Wood and Fiber Science,44(2):196-201.
Joger A,Bader T,Hofstetter K,et al.2011.The relation between indentation modulus,microfibril angle,and elastic properties of wood cell walls.Composites Part A Applied Science&Manufacturing,42(6):677-685.
Meng Y J,Wang S Q,Cai Z Y,et al.2013.A novel sample preparation method to avoid influence of embedding medium during nanoindentation.Applied Physics A,110(2):361-369.
Oliver W C,Pharr G M.1992.An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments.Journal of Materials Research,7(6):1564-1583.
Tze W T Y,Wang S Q,Rials T G,et al.2007.Nanoindentation of wood cell walls:continuous stiffness and hardness measurements.Composite:Part A:Applied Science and Manufacturing,38(3):945-953.
Wang S,Lee S H,Tze W T Y,et al.2006.Nanoindentation as a tool for understanding nano-mechanical properties of wood cell wall and biocomposites.International Conference on Nanotechnology.
Wang X Q,Li X Z,Ren H Q.2010.Variation of microfibril angle and density in moso bamboo(Phyllostachys Pubescens).Journal of Tropical Forest Science,22(1):88-96.
Wang Y R,Leppnen K,Andersson S,et al.2012.Studies on the nanostructure of the cell wall of bamboo using X-ray scattering.Wood Sci Technol,46(1/3):317-332.
Wang H K,An X J,Li W J,et al.2014.Variation of mechanical properties of single bamboo fibers(Dendrocalamus latiflorus Munro)with respect to age and location in culms.Holzforschung,68(3):291-297.
Wang Y R,Liu C W,Zhao R J,et al.2016.Anatomical characteristics,microfibril angle and micromechanical properties of cottonwood(Populus deltoides)and its hybrids.Biomass and Bioenergy,93:72-77.
Yang S M,Jiang Z H,Ren H Q,et al.2009.Variations of the microfibril angle in developmental moso bamboo culms.Journal of Nanjing Forestry University,33(5):73-76.
Yu Y,Fei B,Zhang B,et al.2007.Cell-wall mechanical properties of bamboo investigated by in-situ imaging nanoindentation.Wood and Fiber Science,39(4):527-535.
Yu Y,Tian G L,Wang H K,et al.2011.Mechanical characterization of single bamboo fibers with nanoindentation and microtensile technique.Holzforschung,65(1):113-119.
Zou L H,Jin H,Lu W Y,et al.2009.Nanoscale structural and mechanical characterization of the cell wall of bamboo fibers.Materials Science and Engineering:C,29(4):1375-1379.
Zhao R J,Yao C L,Cheng X W,et al.2014.Anatomical,chemical and mechanical properties of fast-growing Populus×euramericana cv.‘74/76’.IAWAI Journal,35(3):158-169.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |