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标题文本样式:微软雅黑,/26,号,Arial/26pt,第一级内容文本样式:微软雅黑,/20,号,Arial/20pt,第二级内容文本样式:微软雅黑,/18,号,Arial/18pt,第三级内容文本样式:微软雅黑,/16,号,Arial/16pt,第四级内容文本样式:微软雅黑,/14,号,Arial/14pt,第五级内容文本样式:微软雅黑,/12,号,Arial/12pt,本幻灯片资料仅供参考,不能作为科学依据,如有不当之处,请参考专业资料。谢谢,本幻灯片资料仅供参考,不能作为科学依据,如有不当之处,请参考专业资料。谢谢,自修复高分子材料,第1页,自修复又称自愈合,是生物主要特征之一。人们把在无外界作用情况下,材料本身对缺点自我判断、控制和恢复能力称为自修复。当受到外界机械损害后,,自修复高分子材料,能自行发觉裂纹,并经过一定机理将裂纹重新填补,自行愈合。,第2页,自修复高分子材料优势,(,1,),位点专一性,由裂纹引发聚合,针对性强,效率高,;,(,2,)自动化,无需人为观察,节约了监测成本,;,(,3,)提升材料寿命,;,(,4,)消除材料维护成本,;,(,5,)为材料智能化提供思绪,;,(,6,)环境友好性,防止了外加添加剂对环境影响,李思超 韩 朋 许华平,化 学 进 展,第,24,卷 第,7,期 年,7,月,第3页,一类是在材料内部复合功效型物质来实现,自修复,;,另一类是经过向体系提供能量,使材料本身发生共价或非共价作用实现自修复,分类,第4页,第5页,Schematic illustration of the preparation of all-water-based self-repairing super hydrophobic coatings based on U-capsules.,第6页,微胶囊表征,a,、,b)SEM and TEM images of U-capsules.c)EDX spectrum of U-capsules.d)Size,distribution of U-capsules measured by DLS.,第7页,TiO2,含有光催化作用,在紫外光照射下催化微,胶囊,St-DVB,壳分解,释放出含有修复作用氟,代烷基硅氧烷,FAS12.,a,),Schematic representation of the release mechanism in UV-responsive,microcapsules,第8页,FT-IR spectra of FAS12 and the extracted ethanol of the microcapsules,(T1.2-capsules:TiO2 content=1.2%;T0-capsules:TiO2 content=0).,加入,TiO,2,微胶囊红外图谱存在,1205cm,-1,C-F,特征吸收峰说明,TiO,2,催化作用是释放,FAS-12,原因。,第9页,水性自愈合超疏水涂料表征,超疏水材料:接触角大于,150,,滚动角小于,10,接触角,(,contact angle,)是指在气、液、固三相交点处所作气,-,液界面切线穿过液体与固,-,液交界限之间夹角,,是润湿程度量度。,当一滴水放置在固体倾斜表面而到达一个滚动前临界状态时,固体表面倾斜角度就是,滚动角,。,第10页,十七氟癸基三乙基硅氧烷改性二氧化硅(,FMS,),未加入,接触角(,WCA,)只有,86.5,,加入,25wt%,后,WCA,变为,119.3,,滚动角变为,65,。,Variation of WCAs with the amount of FMS nanoparticles in the,U-capsules-embedded coatings(U-capsules/polysiloxane=0.36 wt/wt).,第11页,Photographs of water droplets sitting on the coated samples before a)and after b)UV irradiation in an accelerated weathering tester for 96 h.,有意思是,经过紫外线(,UV,)照射一段时间后,,材料变为超疏水材料。,第12页,在紫外线照射一段时间后接触角增大,,是因为,TiO,2,作用。,第13页,Change of WCA on various nanocomposite coatings before and after UV irradiation in the accelerated weathering tester for 96 h.,为观察涂料表面形貌改变,对紫外线照射前后,试样进行,TEM,试验,发觉照射前后表面形貌基本,一致。,第14页,The appearance of super hydrophobic coatings on different substrates after,UV-irradiation:(a)paper,(b)glass,(c)tin,(d)polypropylene,(e)wood,(f)aluminum,这种涂料作用对象广泛,第15页,紫外线照射下耐久性,对经过不一样紫外照射时间涂料表面进行,XPS,测试,微胶囊在长时间内可保持,FAS12,释放。,第16页,Cross-sectional SEM images of T1.2-capsules-embedded super hydrophobic coatings before(a)and after(b)720h accelerated weathering,对超疏水涂料,720h,后电子扫描显示与之前相比,表面形貌基本一致。,第17页,b)WCAs of the coating versus the accelerated weathering time.Inset:the water droplets on the super hydrophobic coating after prolonged weathering for 720 h.c)WCAs of the coating panel versus outdoor exposure time.Inset:the water droplets on the coating panel after outdoor exposed for more than 720 h.Coating:T1.2-capsules/polysiloxane/FMS.,在加速和正常室外条件下进行测试,在相当长,时间内可保持其超疏水性。,第18页,机械损伤自愈合,a)Change of WCAs for the super hydrophobic coatings as a function of repeated polishing and accelerated weathering cycles.bd)Photographs of water droplets and contact angles on the super hydrophobic surfaces.b)Original sample.c)After 10 cycles.d)After accelerated weathering test for 84 h.Scale bars:5 mm.,经屡次砂纸打磨,-,紫外照射,涂料仍可保持其,超疏水性。,第19页,XPS scans of the coated surfaces(T1.21,original;T1.22,after ten cycles;T1.23,after accelerated weathering test for 84 h).Atomic compositions of the coating,T1.2-capsules/polysiloxane/FMS.,对涂料表面进行,XPS,分析,发觉紫外照射后,,TiO,2,催化微胶囊外壳分解释放出,FAS12,,修,复了机械损伤造成接触角下降。,第20页,油污染后超疏水性能修复,用十八烯酸污染后经紫外线照射恢复超疏水性。,ac)Photographs of water droplets and contact angles on the super hydrophobic,surfaces.a)Original.b)Spread with oleic acid.c)After accelerated weathering test for 36 h.Scale bars:5 mm,第21页,d)Change of the WCAs for the super hydrophobic surfaces as a function of,the cycle number of the oleic acid spreading and accelerated weathering.e)UVVis spectra of the aqueous solutions(dyed with ethylene blue)at different UV-irradiation time in the presence of the super hydrophobic coatings.Coating:T1.2-capsules/polysiloxane/FMS.,屡次污染,自修复后仍含有超疏水性;右图在表面,滴加甲基蓝,紫外照射一段时间后蓝色逐步变浅。,第22页,结论,(,1,)经皮克林乳液聚合合成了包裹,FAS12,微胶囊,加入水性聚硅氧烷,乳液中,可得到紫外诱导超疏水自修复涂层。,(,2,)涂料适用范围广。,(,3,)经机械损伤和有机污染后可自修复恢复超疏水状态。,(,4,)涂料环境友好。,第23页,第24页,二硫键重组,文件所将材料自修复机理就是二硫键,断裂重组。,1,:,TDS diol,2,:,tetraethyl TDS,二硫化四烷基秋兰姆(,TDS,),第25页,高效液相色谱(,HPLC,)证实了前面所讲二硫,键断裂重组。,Variation of molar fractions of three TDS species with time in reshuffling reactions between 1 and 2 under visible light in acetonitrile(0.02 M)at room temperature,第26页,Model reshuffling reactions in a dark place between 1 and 2 in acetonitrile(0.02,M)at room temperature,在黑暗环境下,二硫键断裂重组需要更多,时间。这说明光引发了这个反应。,第27页,ESR spectra of TDS diol 1 and tetraethyl TDS 2 in acetonitrile,电子自旋共振(,ESR,)发觉反应中存在未配对,电子,也可验证上述过程。,第28页,反应存在两种机理,一个是自由基转移,另,一个是自由基交叉反应。,第29页,精密高分子设计,包含结构交换、,链流动性和表面性质对自愈合交联聚合,物十分主要。为了使反应在室温进行,需要,一低,Tg,聚合物。,第30页,Preparation of TDS cross-linked polyurethane 4 by polyaddition of TDS diol(1),TEG,TEA,and HDI in DMF with DBTDL at room temperature,for 24 h.,自愈合材料制备,第31页,1/TEG/TEA/HDI=18/27/10/60.,第32页,Photographs of TDS cross-linked polymer 4a in self-healing reaction.(a)Before self-healing reaction,(b)after cutting cross-linked polymer,and(c)after self-healing reaction for 24 h.,合成材料具备自愈合特征。,第33页,(d)Stress-strain curve,and(e)elongation value at break(%)of cross-linked polymer 4a after irradiation of visible light at room temperature over time.,经过对不一样愈合时间后材料进行力学拉,伸,发觉一段时间后材料基本恢复原来特征。,第34页,红外图谱中不存在异氰酸酯特征吸收峰,22752250 cm 1,,排除了游离异氰酸根对修,复影响。,IR spectrum of cross-linked polymer 4a.,第35页,a)photographs,and b)Elongation values at break of 4a after self-healing reaction,for 24 h in several light condition(First label:before reaction,second label:during reaction),在光照条件下形成自由基一段时间,24h,仍,可起作用。,第36页,Efficiency of self-healing after extended periods of separation.Elongation value at,break(%)of cross-linked polymer 4a that was left with separation in air for 4 h and 24 h,and then irradiated to visible light at room temperature for 24 h with attachment.The plots and the error bars show average values and standard deviations for five measurements,respectively.,试样断裂一段时间后再进行修复效果会变差。,第37页,Effect of TEG and TEA concentrations on mechanical properties and self-healing.,伴随,TDS:TEG,值增加,力学性能变差,,修复性能会相对变好。,第38页,总结,合成了自愈合共价键聚合物,,室温、可见光、空气条件下可通,过自由基重组修复材料。,第39页,第40页,
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