聚丙烯腈/UV327复合纳米纤维膜的防紫外线性能

为了制备防紫外线纳米纤维膜,并开发具有防紫外线功能的纳米纤维纺织品,文中利用静电纺丝技术,将聚丙烯腈(PAN)和紫外线吸收剂UV327的混合溶液纺制成PAN/UV327复合纤维,测试分析了纳米纤维膜的结构和性能。结果表明,PAN/UV327纳米纤维具有较小的纤维直径和直径标准差,其拉伸强度高,伸长率较小;因为UV327含有亲水性的羟基,所以PAN/UV327纳米纤维膜的水接触角更小,润湿性更好。相对纯PAN纳米纤维膜,PAN/UV327纳米纤维膜具有优异的紫外线吸收性能和紫外线防护性能。当纤维膜的厚度为25μm时,PAN纳米纤维膜的紫外线防护系数(UPF)值为21.28,PAN/UV327纳米纤维膜的UPF值为1502.37～1806.05;当纤维膜的厚度从5μm增加到35μm时,2~#PAN/UV327纳米纤维膜的UPF值从50.18增加到1882.28。     

熔体直纺在线添加专用母粒的制备及性能

以聚对苯二甲酸乙二醇酯(PET)为聚合物基体,偶联剂(CA)和分散剂(DA)为助剂,通过对炭黑(CB)粒子进行物理或化学改性,以提高CB粒子在聚合物基体中的分散性,然后采用熔融共混-分离喂料技术制备PET基母粒。母粒的SEM及TEM结果分析表明,CA(NDZ-109)与DA(PE-1)不可复配使用,当CA用量为4%(wt,质量分数,下同)时,可实现CB粒子在PET基体中的良好分散,这与活化指数及理论计算结果相一致。基于熔体直纺在线添加系统,研究了母粒的纺丝组件压力升,PET/CB/4%CA母粒的组件压力较平稳,适于纺丝加工。     

原位聚合法制备炭黑/聚甲基丙烯酸酯导电复合材料

通过原位聚合法制备了炭黑/聚甲基丙烯酸甲酯(CB/PMMA)、炭黑/聚甲基丙烯酸丁酯(CB/PB-MA)和炭黑/聚甲基丙烯酸2-乙基己酯(CB/PEHMA)三种导电复合材料,研究了这三种聚合物基体对复合材料的导电性影响。结果表明:由于炭黑的阻聚作用,当复合材料的炭黑含量增加时,均聚物的数均分子量呈下降趋势,多分散性系数PDI变大。而且炭黑粒子表面发生了接枝聚合反应,这有利于炭黑粒子在聚合物基体中的分散。当聚合物基体的玻璃化温度Tg较高时,复合材料逾渗阈值较低。     

芳纶纤维的紫外辐照改性及硅烷偶联剂二次改性EI北大核心CSCD

采用紫外辐照和硅烷偶联剂KH570二次接枝的方法对芳纶纤维表面进行改性,研究二次改性对芳纶纤维结构及性能的影响,并测试了改性芳纶纤维/炭黑/天然橡胶复合材料的力学性能。结果表明,经紫外辐照改性后,芳纶纤维表面产生活性官能团,为二次接枝提供反应活性点;KH570二次接枝改性后,纤维表面活性和表面粗糙度明显改善,并在其表面引入有助于提高粘合性能的活性官能团。整个改性过程简单、高效和安全。相比于未改性芳纶纤维/炭黑/天然橡胶复合材料(AF/CB/NR),紫外辐照-硅烷偶联剂二次改性芳纶纤维/炭黑/天然橡胶复合材料(KH570-UV-AF/CB/NR)的拉伸强度、100%定伸应力、300%定伸应力、撕裂强度和H抽出力分别提升了17.1%、24.7%、22.4%、48.7%和132.1%。     

芳纶纤维的紫外辐照改性及硅烷偶联剂二次改性

采用紫外辐照和硅烷偶联剂KH570二次接枝的方法对芳纶纤维表面进行改性,研究二次改性对芳纶纤维结构及性能的影响,并测试了改性芳纶纤维/炭黑/天然橡胶复合材料的力学性能。结果表明,经紫外辐照改性后,芳纶纤维表面产生活性官能团,为二次接枝提供反应活性点;KH570二次接枝改性后,纤维表面活性和表面粗糙度明显改善,并在其表面引入有助于提高粘合性能的活性官能团。整个改性过程简单、高效和安全。相比于未改性芳纶纤维/炭黑/天然橡胶复合材料(AF/CB/NR),紫外辐照-硅烷偶联剂二次改性芳纶纤维/炭黑/天然橡胶复合材料(KH570-UV-AF/CB/NR)的拉伸强度、100%定伸应力、300%定伸应力、撕裂强度和H抽出力分别提升了17.1%、24.7%、22.4%、48.7%和132.1%。     

聚酯薄膜表面接枝含氟丙烯酸酯共聚物及其细菌粘附行为研究

利用表面引发原子转移自由基聚合(SI-ATRP)在聚对苯二甲酸乙二醇酯(PET)薄膜表面接枝甲基丙烯酸六氟丁酯(HFBMA)和甲基丙烯酸甲酯(MMA)共聚物。通过红外光谱仪(ATR-FT-IR),X射线光电子能谱仪(XPS)以及扫描电镜(SEM),研究不同反应时间下接枝共聚物对PET薄膜表面组成、结构及性能的影响;利用接触角测试对比研究PET薄膜接枝改性前后的表面疏水性;采用平板菌落计数的方法研究薄膜改性前后的微生物粘附性。结果表明:随着反应时间延长,PET薄膜表面水接触角不断增大,当反应时间为12h时达99.5°,疏水性显著提高;PET薄膜表面对微生物的粘附量随着反应时间的延长而逐渐减少。     

秸秆纳米纤维素与炭黑补强天然胶的界面作用

基于橡胶复合材料的力学性能、交联密度、粘弹行为、热行为、动态性能和形貌结构,利用红外光谱(FT-IR)、X射线光电子能谱(XPS)、差示扫描量热分析、动态力学分析等对酚醛树脂(PF)改性前后秸秆纳米纤维素(SNC)与炭黑(CB)补强的天然橡胶(NR)的界面影响进行了系统分析,并对SNC,PF与NR的成键形式进行了理论分析。FT-IR分析表明SNC-PF上的羟基(-OH)吸收峰发生了蓝移,XPS谱图中显示改性后SNC中O1s结合能升高,说明SNC与PF之间具有强的氢键作用。与NR/CB/PF体系相比,NR/CB/SNC/PF体系在大形变下具有更高的弹性模量(G′),说明其具有更强的橡胶交联网络,该体系具有更高的受限橡胶层质量分数(χ_(im)),说明该材料存在更厚的受限橡胶分子层,意味着其填料更好地分散和填料-基体间更强的相互作用。而NR/CB/SNC/PF复合材料较低的损耗因子(tanδ)、较高的填料-基体间相互作用参数和大应变下较高的上扬临界值(λ~(-1)),都表明其中的填料与NR之间具有更强的相互作用。扫描电镜(SEM)显示PF的加入使填料包埋在NR基体中,且分散更均匀。说明PF的加入使CB/SNC(填料网络)与NR基体形成互穿聚合物网络,填料与NR基体的相互作用增强,交联密度增加,而使CB补强NR的力学性能得到保持或改善。     

高转变温度聚合物PTC材料的研究

研究了以尼龙12（PA12）为基体树脂，炭黑（CB）为导电填料的高转变温度聚合物正温度系数（P11C）材料。采用熔融共混方法制备了PA12/CB聚合物PTC复合材料，研究了炭黑种类、炭黑含量、炭黑表面改性等因素对PA12/CB复合材料PTC性能的影响。结果表明：Vxc305炭黑填充的PA12复合材料，当炭黑含量为30％时，PTC强度可达到105；炭黑表面改性能够抑制材料的NrC效应。     

CB/PBO复合材料制备及吸波性能研究

以4, 6二氨基间苯二酚盐酸盐(DAR?2HCl)、对苯二甲酸(TPA)为原料, 合成TA盐, 再缩聚制得具有较高耐热性的聚对苯撑苯并二噁唑(PBO)。以PBO为基体, 炭黑(CB)为吸收剂, 热压法制备CB/PBO复合材料。对不同炭黑质量分数的复合材料介电及PBO基体与复合材料的热性能进行研究。结果表明, 随着炭黑含量的增加, 材料的复介电常数的实部与虚部均增大。含5%炭黑的试样厚度达到2 mm时, 吸波性能最好, 反射率小于-10 dB的带宽可达2.4 GHz, 最小反射率可达-32 dB。在空气中450℃保温5 h, PBO的质量损失为11.84%, 而5% CB/PBO复合材料的质量损失为21.99%。     

PET/MWNT/CB纳米复合材料制备与性能研究

采用原位聚合方法制备了聚对苯二甲酸乙二醇酯/多壁碳纳米管/炭黑(PET/MWNT/CB)纳米复合材料,研究了MWNT与CB对复合材料导电性能、结晶性能和热稳定性的影响,考察了二者的协同导电效应。结果表明,当MWNT与CB复合填料含量为0.5%(质量分数)时,复合材料的表面电阻为10~(11)Ω。CB与MWNT在PET中能形成"共支撑"网络结构和复合导电通路,具有协同导电效应。二者对PET具有诱导成核与结晶作用,但CB的诱导能力要弱于MWNT。CB的添加对复合材料的热稳定性影响不大。     

非织造材料表面生长ZnO薄膜的特性研究

室温下采用射频磁控溅射技术在涤纶纺粘非织造材料表面生长ZnO薄膜。通过扫描电子显微镜及原子力显微镜对ZnO薄膜的微观结构进行表征,用分光光度计测量样品的透光率。结果表明,ZnO薄膜为纳米级,其平均晶粒大小约为30 nm~55 nm。生长了ZnO透明纳米结构的非织造材料对紫外光有较强的吸收能力,在可见光区的透光率达60%以上。     

Transformation of Poly(dimethylsiloxane) into thin surface films of SiO x by UV/Ozone treatment. Part I: Factors affecting modification

UV/ozone treatment of poly(dimethylsiloxane) (PDMS) was used to produce thin surface films of SiO _x . Films of PDMS were applied by spin-coating onto gold-coated silicon wafers having (100) orientation. Characterization of the UV/ozone system was performed to map the spatial distribution of intensities of UV radiation. This mapping was used to ensure reproducible modification of films and to aid in the understanding of modification as measured by advancing contact angle using deionized water and x-ray photoelectron spectroscopy (XPS). Rutherford backscattering spectroscopy (RBS) was used to measure thickness of the PDMS films. Treatment reduced the wetting angle, in some cases from a value greater than 100° to a value less than 5°. High resolution XPS spectra were used to study the nature of the modified PDMS film and its relationship to the characteristics of the unmodified PDMS. High resolution XPS spectra in the Si 2p region show that O–Si–C bonds in the siloxane, observed prior to treatment, are converted to SiO _x , where x is between 1.6 and 2. Modified films also contain some oxidized carbon components. The time required to reduce the contact angle to a minimum value was greater for the thicker PDMS film samples. The effects of ozone alone (without UV) and UV radiation at 184.9 and 253.7 nm (without ozone) were also investigated. The results of UV/ozone treatment are compared to results achieved by means of plasma surface oxidation.     

透明纳米TiO2薄膜的制备及其紫外光电特性研究

采用溶胶-凝胶法于ITO导电玻璃和石英玻璃基底上制备了均匀透明的TiO2多孔纳米薄膜.XRD和AFM测试结果表明,构成薄膜的TiO2粒子为锐钛矿相,粒径约为50nm.紫外-可见(UV-vis)吸收光谱显示,制得的TiO2薄膜对紫外光表现出很强的吸收特性.借助标准三电极体系进行的光电化学测试结果表明,在紫外光照射下,制得的薄膜电极可产生稳定的阳极光生电流,且电流大小显著依赖于照射光的波长(λ),λ=320nm的光产生的光电流最大.另外,薄膜电极中的光电流大小与电极电位(U)有关.高于0.6V的电位可有效抑制光生电子向电解液的注入,并增大光生电子向导电基底的扩散速度,从而提高阳极光电流的大小.实验结果表明,纳米TiO2薄膜在紫外光传感器的制备方面具有较好的应用潜力.     

炭黑-聚酯复合型导电高分子材料的电热性能研究

研究了炭黑 -聚酯复合型导电高分子材料的电阻率随炭黑填充率及加工成型工艺变化的关系及其伏安特性和力学性能。实验结果表明 ,材料的电导率较高 ,具有非线性伏安特性和负温度系数效应 ,主要用作导电材料和电阻材料。     

钇稳定氧化锆薄膜的制备及其微细加工

以甲醇为溶剂,硝酸氧锆、硝酸钇为前驱物,采用溶胶-凝胶方法,通过引入化学修饰剂乙酰丙酮(AcAcH),使乙酰丙酮和锆离子形成螯合物,得到了具有紫外光感光性的溶胶及其凝胶薄膜,提出了YSZ薄膜的微细图形加工新方法.UV-Vis.分光光度计的紫外光谱测试结果表明:乙酰丙酮与锆离子形成的螯合物在室温、可见光、大气环境下,可以存在于凝胶薄膜中,并具有较好的热稳定性和光化学稳定性,其紫外光谱的特征吸收峰大约在310nm附近;325nm紫外激光光源照射凝胶薄膜,能破坏、分解凝胶薄膜中的这种螯合物结构,使凝胶薄膜的物理化学性质发生变化,实验发现,经过紫外激光照射的凝胶薄膜在适当的有机溶剂(如甲醇等)中的溶解度和溶解速度显著降低,利用这一特性,采用325nm紫外激光通过掩膜照射凝胶薄膜,并在适当的有机溶剂中溶洗掉未受照射的区域,经过800℃,20min热处理,得到了具有微细图形的YSZ薄膜,XRD测试表明该薄膜相结构为立方相.     

Effect of Surface Free Energy of Film Laminated Steel Sheets on Content Release Properties

Polyethylene terephthalate (PET) sheets that are now widely used in beverage cans have excellent properties of formability, corrosion resistance and adhesion to steel sheets. To expand their application, we have sought to develop a new PET film laminated steel sheet for use in food cans. Content release properties are necessary for easy removal of the can contents in food can applications. However, PET film laminated steel sheets have poor content release properties. Investigations of these properties have revealed dependence on the strength of adhesion between the films and can contents. The surface free energy of PET films has been inferred to be the main factor in poor content release properties. Therefore, using films with widely diverse surface free energy values, we studied the effects of surface free energy on the content release properties of materials in contact with cans. The results showed that these properties are closely related to the surface free energy of the film material, and that materials with surface free energy of less than 23 mN/m or greater than 44 mN/m show excellent properties for processed meat products with high protein content. The material with PET film coated with mixture of polyester resin and fatty acid is the most promising material for use in food cans in this study. The work has also shown that content release properties can be expressed as a function of adhesion in water between a material and protein. Reducing adhesion can significantly improve content release properties.     

Preparation of Pb0.98La0.02(Zr0.65Ti0.35)O3 films and their fine patterning

The photosensitive lanthanum-doped lead zirconate titanate (PLZT) gel films were prepared by chemical modification with acetylacetone (AcAcH), and their fourier transform infrared (FT-IR) spectra and ultraviolet visible (UV-Vis) spectra were measured. The results show that the chelate rings of AcAcH with Ti or Zr are formed in the PLZT gel films. With irradiation of UV light, the chelate rings are photolyzed, and lead to a change of the solubility of the PLZT gel films in methanol. Transmission electron microscope (TEM) observations show that the perovskite phase is crystallized in PLZT thin film after heat treatment at 700 °C, whose grain sizes are less than or equal to 60 nm. The PLZT thin films exhibited hysteresis loops and good fatigue properties.     

Magnetic Properties of Anisotropic Pr–Fe–B/Fe/Pr–Fe–B Films

Pr?CFe?CB/Fe/Pr?CFe?CB films with different Fe layer thicknesses were deposited by magnetron sputtering on Si (100) substrate heated at 650?°C. Structural and magnetic properties of the Pr?CFe?CB/Fe/Pr?CFe?CB films were investigated. X-ray diffraction and magnetic measurement results reveal that the Pr?CFe?CB/Fe/Pr?CFe?CB films are anisotropic when the thickness of Fe layer is smaller than 50?nm. The enhancement of the saturation magnetization in nanocomposite films is attributed to the exchange coupling between the soft and hard phases. The highest coercivity of about 13.9 kOe is achieved in the Mo(50?nm)/Pr?CFe?CB(50?nm)/Mo(2?nm)/Fe(2?nm)/Mo(2?nm)/Pr?CFe?CB(50?nm)/Mo(50?nm) film and increasing the thickness of soft-magnetic layer results in a continuous decreasing of the coercivity.     

Cracking phenomena of brittle films in nanostructure composites analysed by a modified shear lag model with residual strain

This paper proposes a modification to the shear lag model for multiple cracking of thin films in order to take into account the residual strain, and uses it to estimate the critical fracture strength of SiOx films with thicknesses from 75 to 660 nm deposited on 12 m-thick polyethylene terephthalate (PET) substrates. It was found that: (1) The difference of residual strains in the film and substrate increased as the thickness of the film decreased. (2) In both initial and multiple formation of cracks, SiOx films failed at almost constant values of a critical stress ranging from 200 to 300 MPa when the thickness was larger than 200 nm, whereas below that it failed at higher values. © 1998 Chapman & Hall     

SiOx/PET复合薄膜的力学性能及阻隔性能

目的基于氧化硅(SiO_x)镀层优异的性能,研究不同厚度的SiO_x层对SiO_x/PET复合薄膜力学性能和阻隔性能的影响,以期得到性能较优的SiO_x/PET复合薄膜。方法以自制的聚对苯二甲酸乙二醇酯(PET)薄膜为基材,采用等离子体增强化学气相沉积法沉积得到SiO_x层厚度分别为40,150,230,320 nm的SiO_x/PET复合薄膜,并进行傅里叶变换红外线光谱分析、力学性能和阻隔性能测试,以及薄膜表观形貌分析。结果沉积SiO_x层后,SiO_x/PET复合薄膜拉伸强度和断裂伸长率随SiO_x层厚度的增大先增大后减小,氧气透过率和水蒸气透过率则出现明显衰减而后逐渐平缓的趋势。SiO_x层厚度达150~230 nm时,复合薄膜的力学性能和阻隔性能表现较优,拉伸强度、断裂伸长率、氧气透过率以及水蒸气透过率分别提高了约25.0%,20.9%,79.3%,77.3%。结论适宜厚度的SiO_x层可以使得SiO_x/PET复合薄膜同时具备较优的力学性能和阻隔性能。