Al_2O_3无机膜的制备及表面自由能计算

以异丙醇铝(AIP)为前驱体,采用溶胶-凝胶法制备Al_2O_3无机膜,并对不同温度焙烧的Al_2O_3无机膜进行接触角测试及表面自由能计算.结果表明,蒸馏水在膜材料表面接触角均小于90°,膜材料表现为亲水特性;随着焙烧温度的升高,Al_2O_3无机膜的表面自由能先减小后增大,当焙烧温度为350℃时,表面润湿性最弱,表面自由能达到最小值54.95×10~(-5)N·cm~(-1),其色散、偶极矩以及氢键分量分别为26.53×10~(-5),14.62×10~(-5)和13.80×10~(-5)N·cm~(-1).     

聚酯单丝等离子体处理后表面能及粘附性研究

利用XPS和接触角等测试方法研究了等离子体处理对聚酯单丝表面能的影响，从材料表面能的角度探讨等离子体处理后聚酯单丝表面润湿性及粘附性改善的机理．结果表明：聚酯单丝经等离子体处理后，表面能中的色散力分量γs^d变化不大，而极性力分量γs^p却大大增加．极性力分量γs^p的增加可使表面能获得较大提高，还能使界面上分子间的取向力和诱导力得到增强，从而有效地改善了聚酯单丝表面的润湿性和粘附性．     

含氟化合物用作纺织整理剂

含氟化合物是仅有的一种能传递水、油和着色剂,并在纺织材料上具有抗污性质的化合物。当一滴油加入纺织品表面,就会和表面形成接触角,并有三种可能的情况: (1)如果接触角>90°,就会形成液滴,很难润湿织物表面。 (2)如果接触角<90°,就能润湿织物表面。 (3)如果接触角为0°,说明液滴对织物表面完全润湿。 接触角取决于材料表面的表面能(SE)和液     

稻草刨花板基材表面润湿性能的研究

通过实验,对稻草刨花板表面自由能以及不同配比的脲醛树脂(UF)和异氰酸酯(MDI)混合胶液对稻草刨花板表面的润湿性能进行了测量和分析。试验结果表明,稻草刨花板的表面自由能高于稻草原料,不同配比的UF和MDI混合胶液在稻草刨花板表面的接触角是随着时间的延长而减小最后逐渐趋于稳定。     

Krüss接触角测试仪

Krüss公司(德国汉堡)生产了3种EasyDrop测试仪分别为Standard、USB与Smart,能够快速简便测量接触角和表面自由能.这三种设备能够满足实验室常规实验和现场测量的全部需要.     

两种秸秆表面润湿性研究

研究测定了异氰酸酯、脲醛树脂和酚醛树脂胶粘剂对高粱秆与玉米秆表面的接触角,并通过测量不同表面张力的液体对秸秆表面的接触角,推算出秸杆表面的自由能.结果表明:秸秆的表面自由能比木材要低得多,属于低能表面固体.     

氨基硅-纳米SiO2杂化材料的制备及超疏水性能

以正硅酸乙酯(TEOS)、γ-(2,3-环氧丙氧基)丙基三甲氧基硅烷(KH560)、N-β-氨乙基-γ-氨丙基聚二甲基硅氧烷(ASO)等为原料,通过溶胶-凝胶和接枝共聚等方法制备了一种氨基硅-纳米SiO2杂化材料(ASO-SiO2),经一浸一轧、烘焙工艺整理,制得了超疏水棉织物,对水的静态接触角达155°.用红外光谱(FT-IR)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、接触角测量仪等仪器研究了杂化材料的结构、微观形貌和超疏水性能.FT-IR分析表明,ASO-SiO2具有预期的分子结构;XPS分析和SEM观察证实,整理的棉织物表面存在一层超疏水杂化有机硅膜和大量的仿荷叶纳米微凸体;接触角测量发现,在一定范围内,随着ASO-SiO2用量的增加,整理棉织物的超疏水性明显提高.     

水性聚氨酯鞋用胶粘剂粘接机理研究(Ⅰ)——界面张力影响

分别测定了不同液体在鞋材聚氯乙烯(PVC)、聚苯乙烯-丁二烯-苯乙烯(SBS)和粘胶剂水性聚氨酯膜的表面接触角,获得了不同基材的表面能参数(Lifshitz-van der Waals分量γ~(LW)、Lewis酸分量和Lewis碱分量γ~+和γ~-),通过粘附功、铺展系数、FT-IR、T型剥离强度测试研究了水性聚氨酯胶粘剂的铺展润湿性、粘接性和界面张力之间的关系。结果表明,界面张力差异是影响铺展、润湿和粘接的主要因素,极性PVC与聚氨酯界面张力差异小,水性聚氨酯粘胶剂润湿铺展性好,粘接性优良;而非极性SBS与聚氨酯界面张力差异大,水性聚氨酯胶粘接性差;SBS表面经卤化和等离子处理引入了极性基团,表面张力中极性Lewis分量增加,铺展润湿性和粘接性明显改善;提高基材表面极性或增加胶粘剂与基材共价键结合是提高非极性基材粘接效果的有效途径。     

超拒水拒油技术

正一般拒水性指放在固体表面的水滴的接触角为90°以上。想到拒水整理时,烃化合物和硅化合物的表面自由能(30mJ/m~2以下)比水的表面张力(72mN/m)低得多,因此用这些化合物进行表面改性,有充分拒水效果。拒油时固体表面的自由能要比油的表面张力(约25mN/m)充分小。氟烷基(Rf)化合物的表面自由能为10~15mJ/m~2,比油的表面张力低得多,可拒水拒油。     

木质素酚在纤维纸张表面层层自组装的研究

为实现纤维纸张表面的疏水改性,利用相分离法制备的毛竹木质素酚(LPS)与Cu~(2+)在纤维纸张表面进行层层自组装。通过动态接触角测量和扫描电镜(SEM)分析对纸浆纤维表面进行表征,结果表明:随着自组装层数的增加,纤维表面的接触角逐渐增大,当木质素酚的组装层数达到4层时,两种纸张纤维表面接触角均达到最大,阔叶浆纸张纤维表面接触角达到110.00°,针叶浆纸张纤维表面接触角达到105.50°,纸张表面从高度亲水性转变为具有一定疏水性,相同的疏水改性实验在阔叶浆纸张上效果优于针叶浆纸张。并且木质素酚因小粒径和链状结构的特点能均匀分布在纤维间,增强了纤维间的结合强度,对纸张的强度起到积极作用,以此开发出一种天然、成本低、制备工艺简单、高强度且表面具有疏水性的纤维基功能材料。     

Evaluation of the compatibility between low pressure melamine (LPM) film printing substrates and inkjet inks

Surface coated wood-based panels play a major role in the forest products industry as materials for construction and furniture elements in numerous interior and exterior applications. Their most important feature besides appropriate mechanical performance and chemical durability is an appealing visual appearance. In this contribution, recent research on the compatibility between two UV-curable inks and different melamine formaldehyde based surface films is presented. The surface texture properties of the printing substrates were investigated by roughness measurements. Substrate surface free energy was measured by contact angle measurements using three different testing liquids covering a wide range of polarities (glycerol, ethylene glycol and diiodomethane). The physical shape of the inkjet ink drops which were placed on the LPM printing substrates was monitored and recorded over time and used as an indicator for the wetting behavior of the tested inks and hence the printability. By combining contact angle and pendant drop measurements the surface tension of the inks was determined. The theoretical findings were confirmed by technological printing tests. To this end, as a hands-on method to establish ink-substrate wetting and compatibility flow coating tests were run and the most suitable ink was selected for printing. The printing results were closely related to the surface properties of the printing substrates.     

模板法制备防污自洁PVDF膜

以二甲基甲酰胺(DMF)为溶剂溶解聚偏氟乙烯(PVDF)粉末,制成涂层胶,并采用不同表面粗糙度的模板对其进行涂层,制备防污自洁PVDF膜。研究了表面粗糙结构和表面能对PVDF膜疏水性能的影响。结果表明,PVDF膜的接触角随表面凸体直径和表面能的减小而增大;滚动角随表面能的减小而减小,与表面粗糙结构无关。采用预涂含氟疏水试剂、表面凸体直径为8.5μm的模板,制得的PVDF膜的接触角为172°、滚动角为2°;采用表面凸体直径为8.5μm的模板,掺杂含氟树脂的PVDF膜的接触角为168°、滚动角为1°,具有优良的防污自洁性能。     

Effect of drying method on the surface wettability of wood strands

An experiment was conducted to investigate the effects of drying methods, namely rotary drum, lab oven, microwave and air-drying, on the surface wettability of wood strands by the Wilhelmy plate method. The measurements included the surface contact angle, free energy, and liquid sorption capacity. Thirty industrial strands including southern yellow pine (Pinus spp.) and poplar (Populus spp.) were randomly collected for each drying method. The results from this study showed that the surface contact angle of a strand depends on the liquid used as well as the drying method and wood species. Liquid sorption capacity of the pine strands increased with decreasing surface contact angle, but this trend was not observed with the poplar strands. The total surface energy was almost the same for strands within species, regardless of the drying method, but it was higher on poplar strands than on pines. The polar and disperse components of surface free energy varied with both drying method and wood species. The surface polar energies of oven-dried pine strands and rotating drum-dried poplar strands were higher than on strands dried by other methods. For lower temperature drying methods (air and microwave), the lowest polar component was observed on the radial face of the pine strands. For the higher-temperature drying methods (oven and rotary-drum), the lowest polar component was found to on the tangential face of the pine strands.     

Adhesion modeling on rough low linear density polyethylene

ABSTRACT:  Food adhesion is an important attribute that could have both positive and negative ramifications depending on the application. Yet, its quantification remains cumbersome and as a consequence adhesion models are scarce. The effect of surface roughness, free energy, and ozone treatment on adhesion of rough low linear density polyethylene films was investigated. Adhesion was measured by a 180° peel strength test. The plastic films were roughened (surface roughness ratio, r , ranged from 1.00 to 1.15). Exposing the film to ozone treatment (0 to 300 s) modified its surface free energy, γ _s (32.4 to 37.9 mJ/m², respectively), and its polar component of the surface free energy, γ ^p _s (3.0 to 8.3 mJ/m², respectively). The films were coated with polyurethane capable of forming hydrogen bonds. Adhesion was found to be a function of the apparent contact angle of water, θ _{ap [water]}, surface roughness ratio, and surface free energy. The linear relationship between the apparent contact angle of water, θ _{ap [water]}, and γ ^p _s was incorporated in building an empirical model that quantifies peel strength as function of r and γ ^p _s . The model showed good agreement with experimental data, especially for longer ozone exposures and rougher surfaces. The empirical model provides insight into the relationships between surface roughness, surface energy, and adhesion. Quantifying these effects could facilitate reducing biofilm forming on food equipment, antisticking treatments, or easy peel packages, or reducing food residues adhering to the food packages and consequently minimize oxidation, off flavors, and waste.     

Wetting properties of food packaging

A top-view vibration system for measuring the apparent contact angle corresponding to the global energy minimum was applied in quantifying the effect of plastic film, roughness, and surface treatment on wettability. Liquids representing typical pure liquids (diiodomethane, ethylene glycol) and food products (10% ethanol, 3% fat milk, 10% sucrose, triolein) were tested on low linear density polyethylene (LLDPE) and polyethylene terephthalate (PET), exposed, or not, to commercial corona discharge treatment (CDT). Apparent contact angle values increased with surface tension of the liquid. The counterpart data derived by the common advancing method were higher, and could lead to erroneous values and misleading interpretations. The major effect of CDT was to enhance surface polarity by significantly increasing the polar component of surface free energy. Interactions between the packaging material and food could have a major effect on product quality, and should therefore be taken into consideration.     

可食性喷墨油墨性能对印刷品质量的影响

可食性喷墨油墨为水性油墨,绿色环保,其原料全部符合食品卫生标准,可以用喷墨印刷的方式直接在食品、药品或产品的包装表面印刷,具有色彩鲜艳、无毒、无污染的特点。采用在油墨中添加不同含量的染料、树脂及表面活性剂的方法,改变油墨的黏度和表面张力,探讨不同性能的可食性喷墨油墨对印刷品质量的影响。采用CCD图像检测分析系统,对印刷品的线条质量、实地填充质量及圆点质量进行评价和分析;用密度计测量印品的色密度并进行颜色评价。结果表明,可食性喷墨油墨的黏度和表面张力影响印刷品的质量,通过调整树脂及表面活性剂用量,可以获得适于喷墨印刷的可食性喷墨油墨。     

In vivo measurement of the surface energy of human fingernail plates

The surface energy of the human nail plate is expected to influence the adhesion of microorganisms (and subsequent colonization and infections) as well as that of medicines (and subsequent drug permeation) and of cosmetics. The aim of the study was therefore to measure the surface energy of nail plates in vivo. The surface energy of healthy human fingernails (untreated, hydrated and abraded) and of hoof membranes (often used as a model for the nail plate) was estimated from contact angle measurements of liquids (water, formamide, diiodomethane and glycerol) on the nail plate and subsequent computation using the Lifshitz-van der Waals/acid-base (LW-AB) approach. The surface energy of untreated fingernail plates was found to be 34 mJ m(-2) . Most of this total energy was from the apolar Lifshitz-van der Waals component. When the polar component of the surface energy was analysed, the electron donor component was considerably larger than the electron acceptor one. Hydrating the nail plate had no significant influence on the surface energy. In contrast, abrasion caused a small, but statistically significant increase in the apolar surface energy component. The surface energy of bovine hoof membrane was similar to that of the fingernail plate. We conclude that the human fingernail plate is a low-energy surface and that bovine hoof membranes may be used as a substitute for the nail plate in certain experiments.     

电晕处理对塑料表面性能及印刷适性影响的研究

随着包装印刷的迅速发展,塑料承印材料在包装印刷中的应用越来越广泛.由于塑料材料的表面能比较低,油墨难于附着在塑料表面,因此提高油墨在塑料表面的润湿性成为塑料印刷工艺中亟待解决的问题.从实际生产出发,对塑料表面采用电晕处理,通过改变不同电晕条件得到不同表面能的塑料承印材料.用UV胶印油墨打样实验,探讨塑料表面性能对油墨附着力、油墨转移率、密度以及叠印率等印刷适性的影响.研究结果表明,提高塑料的表面能可以提高油墨的附着力,有利于油墨转移.