麦秆表面自由能及其分量研究

连续跟踪不同处理麦秆表面接触角随时间的变化值,确定用于计算表面自由能的接触角数据,依据Young方程及Owens-Wendt-Kaelble法,求解不同处理麦秆表面自由能及其极性和非极性分量(色散力分量)。结果表明,未经处理麦秆外表面自由能为37.20 mJ/m2,其非极性分量占84.11%,内表面自由能高达51.54 mJ/m2,其非极性分量占50.50%。经1%的NaOH溶液95℃和85℃热处理,麦秆外表面自由能由37.20 mJ/m2增至51.72 mJ/m2和44.21 mJ/m2,其极性分量增加了377.58%和229.13%。经180℃和160℃热处理,麦秆外表面自由能变化不显著,但其极性分量显著增加,非极性分量显著降低。     

玉米秸秆粉/HDPE复合材料表面特性的研究

采用毛细管上升法测定了不同探测液在未改性玉米秸秆粉和4%硅烷偶联剂改性玉米秸秆粉表面的接触角,依据Washburn方程,采用Owens-wendt-Kaelble途径,计算了未改性玉米秸秆粉和改性玉米秸秆粉的表面自由能及其分量。结果表明:未改性的玉米秸秆粉的表面自由能为28.88mJ/m2,体现分子极性的极性分量为22.20mJ/m2;而改性玉米秸秆粉的表面自由能为35.69mJ/m2,体现分子极性的极性分量为3.51mJ/m2。因此,在与热塑性塑料复合时,改性玉米秸秆粉有更好的界面相容性。玉米秸秆粉/HDPE复合材料的弯曲断面形貌进一步证实了改性玉米秸秆粉有更好的界面相容性。     

类金刚石薄膜的表面性能研究

利用微波-ECR等离子体源全方位离子注入设备,采用PSII与PSII+PECVD工艺在医用316L不锈钢上制备碳改性薄膜.Raman光谱分析表明,薄膜为典型的类金刚石(DLC) 薄膜.静态接触角测量技术研究表明:在酸碱溶液中,DLC薄膜表面价键遭到破坏,稳定性降低.不同工艺制备的DLC薄膜表面能在40mN/m左右,极性分量大于色散分量,呈现出疏水性质.DLC薄膜表面能高低取决于表面碳碳键与粗糙度的变化.     

原子转移自由基聚合法在硅橡胶表面接枝聚甲基丙烯酸甲酯

采用表面引发原子转移自由基聚合(SI-ATRP)在室温硫化硅橡胶表面接枝聚甲基丙烯酸甲酯(PMMA)。通过衰减全反射傅立叶变换红外光谱(FT-IR/ATR)、X射线光电子能谱(XPS)、接触角和扫描电子显微镜(SEM)对改性前后硅橡胶表面结构、表面形貌及表面润湿性进行表征。结果表明,在硅橡胶表面成功接枝了PMMA;随着聚合时间的延长,单位面积上的接枝量逐渐增大,当聚合时间为16h时,接枝量达到3.75mg/cm2;接触角从108.8°下降到71.7°;表面自由能从17.7mN/m增大到32.0mN/m。     

接触角测定法研究碳纤维表面酸碱性

用接触角测定法研究了未处理的和经液相氧化处理的碳纤维表面的酸碱性。结果表明,未处理碳纤维表面呈两性,但以碱性为主;经氧化处理后,碳纤维表面的酸性变化不大,而碱性变得更强。得到碳纤维表面自由能的非极性分量为45mJ/m~2。     

原子转移自由基聚合法在硅橡胶表面接枝聚甲基丙烯酸甲酯EI北大核心CSCD

采用表面引发原子转移自由基聚合(SI-ATRP)在室温硫化硅橡胶表面接枝聚甲基丙烯酸甲酯(PMMA)。通过衰减全反射傅立叶变换红外光谱(FT-IR/ATR)、X射线光电子能谱(XPS)、接触角和扫描电子显微镜(SEM)对改性前后硅橡胶表面结构、表面形貌及表面润湿性进行表征。结果表明,在硅橡胶表面成功接枝了PMMA;随着聚合时间的延长,单位面积上的接枝量逐渐增大,当聚合时间为16h时,接枝量达到3.75mg/cm2;接触角从108.8°下降到71.7°;表面自由能从17.7mN/m增大到32.0mN/m。     

不同细度矿渣粉体表面能的薄层渗析法测量

根据薄层毛细渗析的基本原理,通过测定不同液体在矿渣粉体表面的接触角,对不同细度矿渣粉体的表面能状态进行对比研究。结果表明,采用喷涂制板、密闭称量及视频记录等方法,可获得稳定性与重现性良好的接触角测量结果;以二碘甲烷、乙二醇和水为探针液,测得粗、中、细粒径矿渣粉体的总表面能分别为23.63、32.49、34.59 mN/m,矿渣粉体颗粒表面能的非极性成分随着粒径的减小而增大,极性成分随着粒径的增大而增大。     

炭纤维表面物理特性的表征及其对浸润性能的影响

采用反气相色谱法对除浆前后T300B炭纤维的比表面积、溶解度参数和表面能进行了表征测试,分析了炭纤维表面物理特性对纤维和树脂浸润性能的影响。以一系列不同浓度的正庚烷为吸附质,根据BET吸附理论模型,计算得到除浆前后T300B纤维的比表面积分别为0.43m2/g和0.39m2/g。以正癸烷、正壬烷、正辛烷和正庚烷为非极性溶剂探针,甲苯、二氯甲烷、乙醇、1,4-二氧六环和丙酮为极性溶剂探针,采用DiPaola和Guillet方法得到不同探针分子与纤维表面的Flory-Huggins相互作用参数,计算除浆前后T300B的溶解度参数(δ)分别为11.98MPa1/2和10.01MPa1/2。T300B纤维的上浆剂可以增大纤维表面能的极性分量,使上浆纤维的溶解度参数与E51环氧树脂的δ(11.78MPa1/2)更为接近,提高了T300B纤维与树脂的浸润性能。     

等离子改性条件对PEGDA/HEMA凝胶亲水性及表面能的影响

采用氩等离子对聚乙二醇双丙烯酸酯(PEGDA)/甲基丙烯酸-2-羟基乙酯(HEMA)共聚物凝胶进行表面改性,对膜材料进行了光电子能谱(XPS)分析,并讨论了等离子处理时间及功率对凝胶亲水性及表面能的影响。研究结果表明,经等离子处理后凝胶表面引入了含氧极性基团,氧的含量从未处理的23%增加到26%,使材料亲水性得到改善;由于引入极性基团,材料的表面能随等离子处理时间和功率的增加而增加,从未处理前的45.9 mJ/m2增加到72.5 mJ/m2,极性力分量γPs随等离子体处理功率和时间的变化规律与表面能γs基本一致。     

葡萄糖酰胺非离子双子表面活性剂的制备与表征

以烷基胺、1,3-二溴丙烷为主要原料,采用两步法合成了不同碳链长度(n=8、12、16)的N,N′-二烷基(8/12/16)-N,N′-二葡萄糖丙二酰胺非离子双子表面活性剂。通过FTIR与1 HNMR对产物的结构进行了表征,用悬滴法对其表面张力进行了测定,用动态光散射对其粒度分布进行了测定,用改进Ross-Miles法对样品的泡沫性能进行了测定。结果表明:合成的葡萄糖酰胺非离子双子表面活性剂(8/12/16)的临界胶束浓度(cmc)及γcmc分别为5.627×10-3 mol/L、4.42×10-4 mol/L、2.96×10-3 mol/L和36.20mN/m、30.22mN/m、46.35mN/m;双子表面活性剂溶液粒径分布在130～1050nm;双子表面活性剂泡沫性能良好。     

光固化全氟改性环氧丙烯酸酯的合成与性能

以环氧树脂、全氟辛酸、丙烯酸等为原料合成了一种可光固化的环氧全氟辛酸酯丙烯酸酯(EFOA)低聚物。利用1H-NMR、IR、元素分析、DSC、TGA、接触角以及凝胶含量法等分析手段对低聚物的结构、氟含量、固化膜的热性能,表面自由能以及光固化过程的影响因素进行了研究。结果表明,与EA/HD-DA光聚合物相比,EFOA/HDDA聚合物具有较好的热稳定性;随着预聚物EFOA/EA/HDDA中EFOA含量的增加,固化膜对水和CH2I2的接触角迅速增大,表面自由能大幅度下降至19.97 mN/m。     

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.     

成膜基材对含氟丙烯酸酯/聚氨酯复合乳液自组织梯度化结构的影响EI北大核心CSCD

采用细乳液法制备含氟丙烯酸酯/聚氨酯复合乳液FPAPU,研究4种不同表面性能的成膜基材(铝板、不锈钢板、PTFE板、玻璃板)对FPAPU乳胶膜中含氟组分自组织梯度化分布结构的影响。结果表明:在铝板和不锈钢板上成膜其梯度化结构不明显;而在PTFE和玻璃板基材上成膜后,存在一定梯度化结构。特别是在玻璃板上成膜,含氟组分含量从膜-基材(F-S)面向膜-空气(F-A)面梯度化增加,膜两面差异性明显,其表面自由能差异达到11.71 mN/m,从F-S面到F-A面形成明显分层结构,F-A面粗糙度较大,水和油(二碘甲烷)在其上的接触角可达到121.6°及90.6°,具备优异的疏水疏油性。     

高表面活性的水性聚氨酯乳液的制备及性能

以甲苯二异氰酸酯(TDI)、嵌段聚醚二醇PE6100以及聚醚胺ED-2003为原料,采用自乳化法合成了固含量40%的非离子型水性聚氨酯(WPU),通过红外光谱(FT-IR)对产物的结构进行了分析,并对产物的粒径、流变性能、表面张力、临界胶束浓度(CMC)进行了研究,结果表明,得到的WPU具有一定的触变性,平均粒径大多为100nm~400nm,在1g/L的浓度时水溶液的表面张力不超过37mN/m,具有较好的降低水溶液表面张力的能力。     

纳米碳纤维表面修饰及其在水溶液中的分散

为了研究纳米碳纤维(CNFs)在水溶液中的分散情况,对其进行高温纯化处理,以甲基纤维素(MC)为分散剂,制备分散良好的CNFs悬浮液.采用差热分析(DTA)和热重分析(TGA)研究了高温处理对CNFs的影响,通过测定悬浮液的紫外可见光吸光度、等温吸附曲线、zeta电位及表面张力等方法研究了MC对CNFs分散性能的影响,并讨论分析了MC对CNFs的分散机理.结果表明:MC的加入使CNFs悬浮液的zeta电位由-15.4 mV升至0,表面张力由38.87 mN/m降至36.54 mN/m;等温吸附曲线表明MC在CNFs的表面为"单阶段吸附",当MC的质量浓度达到0.4 g/L时,MC在CNFs表面饱和吸附;当CNFs达到最佳分散状态时,MC与CNFs的质量比为2∶1.     

Evaluation of wettability and surface energy of native Nitinol surfaces in relation to hemocompatibility

In the present study the dependence of Nitinol contact angles and surface energy on surface treatment is explored in order to better understand the material hemocompatibility that was evaluated in our previous studies. It is found that in the group of surfaces: (1) mechanically polished, (2) additionally heat treated, (3) chemically etched, and (4) additionally boiled in water, and (5) further heat treated, the contact angle could vary in the 50°–80° hydrophobic range and the total surface free energy in the 34–53 mN/m range. The polar surface energy, varying from 5 to 29 mN/m, constitutes a decisive contribution to the total energy change, and it seems to be a direct function of the Nitinol surface chemistry. Based on the complex analysis of surface energy together with the earlier results on electrochemistry and hemocompatibility it is concluded that the alteration of the polar component of surface energy and thrombogenicity is due to changes of the electron-acceptor/electron-donor character of native Nitinol surfaces during surface treatments.     

Preparation and characterization of calix[6]arene Langmuir-Blodgett thin film

Calix[6]arene monolayer/multilayer was prepared on a glass substrate and the behavior of monolayer properties investigated at the air-water interface by taking Langmuir isotherm graph. UV-visible, wettability measurements, atomic force microscopy and quartz crystal microbalance measurements were used to monitor the deposition quality of this Langmuir-Blodgett film. Our results showed that a uniform and high quality film with a transfer ratio of approximately 0.99 occurred using the calix[6]arene material at a deposition pressure of 21 mN/m. The surface free energy was determined to be 25.86 mN/m based on contact angle measurements.     

磺化氧化石墨烯/聚砜复合膜的制备及抗污染性能

采用浸没沉淀-相转化法制备了磺化氧化石墨烯/聚砜（SGO/PSf）复合膜,对SGO/PSf复合膜的亲水性、纯水通量、孔隙率、表面Zeta电位、膜断面和表面形貌进行测定。为了分析SGO/PSf复合膜的抗污染性能,采用自制牛血清白蛋白（BSA）探针,借助原子力显微镜（AFM）测定了SGO/PSf复合膜与BSA之间的黏附力。结果表明,由于SGO与聚乙烯吡咯烷酮（PVP）的协同作用,SGO含量为0.5wt%的SGO/PSf复合膜的表面自由能最大（114.47 mJ/m2）,亲水性最好,对BSA的截留率为97.5%,污染恢复率达到80.06%。BSA与SGO含量为0.5wt%的SGO/PSf复合膜之间的黏附力最小（-0.61 mN/m）,说明SGO含量为0.5wt%的SGO/PSf复合膜的抗污染能力最强。      

Fluoroalkylated silicon-containing surfaces-estimation of solid-surface energy

The design of robust omniphobic surfaces, which are not wetted by low-surface-tension liquids such as octane (γlv=21.6 mN/m) and methanol (γlv=22.7 mN/m), requires an appropriately chosen surface micro/nanotexture in addition to a low solid-surface energy (γsv). 1H,1H,2H,2H-Heptadecafluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS) offers one of the lowest solid-surface energy values ever reported (γsv≈10 mN/m) and has become the molecule of choice for coating textured surfaces. In this work, we synthesize and evaluate a series of related molecules that either retain the POSS cage and differ in fluoroalkyl chain length or that retain the fluorodecyl chains surrounding a linear or cyclic molecular structure. The solid-surface energy (γsv) of these molecules was estimated using contact angle measurements on flat spin-coated silicon wafer surfaces. Zisman analysis was performed using a homologous series of n-alkanes (15.5≤γlv≤27.5 mN/m), whereas Girifalco-Good analysis was performed using a set of polar and nonpolar liquids with a wider range of liquid surface tension (15.5≤γlv≤72.1 mN/m). The hydrogen-bond-donating, hydrogen-bond-accepting, polar, and nonpolar (dispersion) contributions to the solid-surface energy of each compound were determined by probing the surfaces using a set of three liquid droplets of either acetone, chloroform, and dodecane or diiodomethane, dimethyl sulfoxide, and water.     

Imaging nanometer scale optical heterogeneities in phospholipid monolayers deposited on metal island films

Near-field scanning optical microscopy was applied to study the distribution of fluorescently labeled phospholipid monolayers deposited on the surface of gold island films by the Langmuir-Blodgett technique. Nanometer scale (approximately 50 nm) optical heterogeneities were observed in near-field fluorescence images of the monolayer deposited at 10 mN/m surface pressure. At higher surface pressure (30 mN/m) the heterogeneities became less pronounced. Overlaying of the near-field transmission and fluorescence images from the same area of the sample shows local transmission of gold island film is at a minimum where the fluorescence of the lipid monolayer is at a maximum. It was concluded that coverage of the metal island film by the Langmuir-Blodgett phospholipid monolayer is incomplete, and lipid molecules are preferentially localized in crevices of the film.