Study on the enhancement of the interface performance between CF and polyimide by triethylamine grafting nano-TiO2 particles

The TiO₂ is grafted by triethylamine and is introduced on the surface of the carbon fiber, which improves the wettability and activity of the carbon fiber surface and at the same time strengthens the carbon fiber/polyimide composite. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the triethylamine grafting successfully on TiO₂. Scanning electron microscope (SEM) results show that when the trimethylamine concentration is 1.0%, a uniform coating is formed on the surface of the carbon fiber. The interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) were increased by 32% and 69%, respectively.     

The effect of electrophoretic deposition p-aminobenzenesulfonamide grafted CNT on mechanical properties of carbon fiber filled polyamide 6 composite

The surface treatment of carbon fiber is carried out by electrophoretic deposition of p-aminobenzenesulfonamide grafted carbon nanotube (CNT), and it is used as a reinforcement of polyamide 6. The monofilament tensile test and XPS were used to study the effect of p-aminobenzenesulfonamide concentration on the tensile strength and surface functional groups of carbon fiber monofilaments. The results show that the higher the p-aminobenzenesulfonamide concentration, the greater the decrease in the mechanical properties of carbon fibers, and the greater the content of oxygen-containing functional groups on the surface. It is preferred that carbon fiber and thermoplastic polyamide 6 with higher retention rate of monofilament tensile strength and rich oxygen-containing functional group content are made into composite materials, and the interlaminar shear strength (ILSS) is evaluated.     

The interfacial adhesion of wood fiber–reinforced UHMWPE composite filled with acid‐treated clay

Wood fiber–reinforced ultrahigh molecular weight polyethylene (wood fiber/UHMWPE) composites have been filled with acid‐treated clay to enhance the adhesion. According to the modification, the interlaminar shear strength of composites has been greatly improved. X‐ray photoelectron spectroscopy and scanning electron microscopy are used to examine the microscopic properties of resultant composites. The enhanced interlaminar shear strength is attributed to the clay interlock, which improves the wetting between wood fibers and resins.     

过渡金属掺杂TiO_2/活性炭复合体的制备及双协同光催化性能

以活性炭为载体,通过溶胶-凝胶法分别制备了Fe、Ag、Zn、Mn和Cr过渡金属离子掺杂TiO2/活性炭(X-TiO2/AC,X-TA;X:过渡金属离子)复合体,利用X射线衍射(XRD)、比表面积(BET)、X光电子能谱(XPS)、扫描电镜(SEM)、电子自旋共振谱(ESR)和荧光光谱(FS)对其结构进行表征.以罗丹明B的光催化降解为探针实验,评价掺杂负载型复合体的双协同光催化性能和使用寿命,提出双协同光催化扩增机制,并探讨了掺杂率和负载率对双协同扩增效果影响.结果表明:通过活性炭吸附和离子掺杂对TiO2光催化性能表现出双协同扩增作用,导致X-TA对罗丹明B的降解速率常数kapp大于掺杂X-TiO2粉体和TA负载体之和.同时,掺杂率和负载率共同影响协同效应,当Fe离子掺杂率和Fe-TiO2负载率分别为0.3%和10%时,Fe-TA复合体kapp最大为0.0208min-1.另外,过渡金属离子掺杂对TiO2光催化性能提高程度按掺杂离子Ag、Zn、Mn、Cr、Fe递增.掺杂后金属离子的价态、得电子能力、比表面积和掺杂TiO2颗粒尺寸上的差异决定了不同离子掺杂负载型复合体催化性能不同,复合体寿命降低的主要原因是由于活性组分从载体上流失所引起.     

Plasma treatment of bamboo fibers on the tribological property of polyimide composite filled with graphite

This paper is concerned with the effects of the air plasma surface treatment of bamboo fiber on the tribological properties of the bamboo fiber reinforced polyimide (bamboo/polyimide) composites filled with graphite. Plasma treatment and graphite bring positive effect on the improvement of friction reducing and antiwear of bamboo/polyimide composites. And Fourier transform infrared spectroscopy analysis shows that the bamboo fibers have been oxidized and etched by the air plasma treatment. The presence of active groups makes the polarity of the fiber increase, and so the bond property between the fiber and matrix is improved.     

The mechanical properties of surface treated UHMWPE fibers and TiO2 reinforced PMMA composite

Mechanical properties of hybrid PMMA composites reinforced with UHMWPE fiber and nano‐titanium dioxide (2, 4, 6, and 8 wt%) was investigated. In this work, the effect of UHMWPE fiber surface treatment on tensile, flexural, and impact properties of PMMA composites was studied. The fiber loadings were varied from 0% to 20%. The addition of UHMWPE fiber had caused a decline in the tensile strength of the PMMA composite. Results revealed that the presence of titanium dioxide on the surface treated UHMWPE fiber has further enhanced the efficiency of stress transfer from the matrix to the fiber thus improved the interfacial adhesion between the UHMWPE fiber and PMMA matrix.     

TiO_2/ACF光催化剂的超声波制备及其光催化活性

本文以超声波为晶化方法在低温下制得了炭纤维负载的Ti O2光催化剂(Ti O2/ACF)。通过X衍射、扫描电镜、液氮吸附等对晶化中所得催化剂Ti O2的晶型、形貌和织构进行了考察,并以甲基橙为降解物考察了催化剂活性。结果表明:在超声波作用下,Ti O2前驱体先被均匀负载到炭纤维表面,然后被晶化为14.2 nm的锐钛矿粒子;所得催化剂晶粒在炭纤维表面形成了1.1nm左右的微孔,其介孔体积比炭纤维高;超声晶化时间对晶粒大小无明显影响,但对催化剂活性有重要活性影响:60分钟的晶化活性最好,过长时间会使负载的Ti O2脱落,降低催化剂活性。实验结果还表明,Ti O2/ACF催化剂在重复使用中活性基本稳定,且对甲基橙吸附比原炭纤维高,其原因在于催化剂介孔体积的增加。     

Flexible electrospun PET/TiO2 nanofibrous structures: Morphology,thermal and mechanical properties

In this study, a solvothermal method was used to synthesize anatase titanium dioxide (TiO₂) nanoparticles in the presence of oleic acid (OA) and oleylamine (OM) as morphology‐directing agents. Functional nanocomposite fibers of poly(ethylene terephtalate) (PET) containing surfactants‐capped TiO₂ nanoparticles were developed by electrospinning technique. The morphology, thermal stability and mechanical properties of PET/TiO₂ nanocomposite mats were investigated as a function of TiO₂ concentration. Morphology investigation showed interesting results in terms of the level of TiO₂ dispersion inside the fibers and the improvement of the quality (smoothness) of the fibers' surface when the synthesized nanorhombic TiO₂ nanoparticles were used compared to a commercial P25 TiO₂ (AEROXIDE P25)_. The presence of OA and OM on the surface of the nanorhombic synthesized TiO₂ led to a significant improvement of TiO₂ dispersion inside the PET matrix. Furthermore, the physical interaction between the PET matrix and TiO₂ nanoparticles resulted in an enhanced thermal stability, and an increase of the Young's modulus and tensile strength for TiO₂ concentration up to 10 wt%.     

The addition of clay on the mechanical properties of surface‐treated CF‐filled PA66 composites

Polyamide 66 (PA66) composites filled with clay and carbon fiber (CF) were prepared by twin‐screw extruder in order to study the influence of nanoparticle reinforcing effect on the mechanical behavior of the PA66 composites (CF/PA66). The mechanical property tests of the composites with and without clay were performed, and the fracture surface morphology was analyzed. The results show that the fracture surface area of the clay‐filled CF/PA66 composite was far smoother than that of the CF/PA66 composite, and there formed a tense interface on the CF surface after the addition of clay. The tensile and flexural strength of CF/PA66 composites with clay was improved. The impact strength decreased because of the high interfacial adhesion. In conclusion, the addition of clay favored the improvement of the higher interface strength and so had good effect on improving the tensile and flexural properties of the composites. Copyright © 2017 John Wiley & Sons, Ltd.     

超声协同TiO_2光催化脱除燃料油中有机硫的研究

采用溶胶凝胶法制备纳米TiO2光催化剂,引入超声作用,以空气中的氧气为氧化剂,正辛烷为模拟油品对燃料油中硫化物的脱除进行了研究。考察了光照强度、催化剂用量、反应时间、二苯并噻吩(DBT)初始浓度、超声功率等因素对TiO2光催化二苯并噻吩溶液降解效率的影响。结果表明,引入超声后DBT的降解率提高了10%左右,并在TiO2用量为2 g/L,通气量为800 mL/min,光照距离20 cm,DBT初始浓度为600 mg/L,反应时间为150 min,超声功率为500 W的条件下,DBT降解率达到了72.6%。     

The addition of acid treated carbon nanotube on the interfacial adhesion of carbon fiber reinforced UHMWPE composite

Carbon fiber reinforced Ultra High Molecular Weight Polyethylene (CF/UHMWPE) composites have been filled with acid treated carbon nanotube to enhance the adhesion. According to the modification, the interlaminar shear strength (ILSS) of composites has been greatly improved. Dynamic wetting method, XPS and SEM are used to examine the microscopic properties of resultant composites. The enhanced ILSS is attributed to the CNT interlock, which improves the wetting between carbon fibers and resins. Copyright © 2017 John Wiley & Sons, Ltd.     

TiO2 films by sol-gel spin-coating deposition with microbial antiadhesion properties

Intensive use of antibiotics induced adaptations in bacteria, which developed antibiotic resistance. This is becoming a serious health problem, particularly in the hospital, food industry, or public transport. It is also important to produce surfaces that not only are bactericidal but also prevent adhesion and the consequent biofilm formation, which can make the bacteria resistant to conventional disinfection methods. In this work, a simple and inexpensive method to obtain surfaces TiO₂ film coated has been realized to prevent attachment and bacterial proliferation on surfaces. The synthesis and deposition procedure has been finalized to the realization of a uniform coating, whose physical, morphological, and structural features are suitable to inhibit the proliferation of the bacteria and in particular the adhesion of the biofilm. The suitability of the obtained coating has been attested by RBS, X-ray diffraction (XRD), SEM, UV-vis, and Raman techniques. The obtained coatings were homogeneous anatase titania films with an excellent adherence to the substrate and a transmittivity higher than 80% in the visible region. The results show that the TiO₂ films considerably reduce microbial contamination on the surface (~98% reduction) feature that makes this coating suitable for antibacterial applications.     

Mechanical properties of surface treated UHMWPE fiber and SiO2 filled PMMA composites

The hybrid reinforcement effect of surface‐treated UHMWPE fiber and SiO₂ on the mechanical properties of PMMA matrix composites was investigated. When UHMWPE fiber is introduced, the tensile strength of UHMWPE fiber‐reinforced composites sharply increases. The flexural modulus was enhanced with an increase in filler loading. Flexural modulus of the treated UHMWPE/SiO₂/PMMA composites was higher than that of the UHMWPE/PMMA and UHMWPE/SiO₂/PMMA composites. The outcome of the better interfacial bonding between the filler and the matrix is reflected in the improvement of the mechanical properties of the treated UHMWPE/SiO₂/PMMA composites. Copyright © 2017 John Wiley & Sons, Ltd.     

The flexural and tribological properties of UHMWPE composite filled with plasma surface‐treated wood fibers

In this paper, the wear performance of an ultra‐high molecular weight polyethylene composites filled with wood fiber were studied using a pin‐on‐disc method. The effects of surface treatment of wood fiber and sliding load and on the friction and wear of the wood fiber/UHMWPE composite are reported. The test results showed that the sliding load is an important controlling factor; its effect is diminished when the wood fiber is modified.     

超临界流体干燥法制备TiO2／C纳米粒子及光催化性能

以TiCl4为原料,采用溶胶凝胶法结合超临界流体干燥法(SCFD)制备了纳米级TiO2/C复合光催化剂.以苯酚的光催化降解对所得催化剂的催化活性进行了评价.结果表明,纳米TiO2/C复合粒子与单组分TiO2比较,复合粒子光催化活性高于单组分的TiO2,h苯酚降解率高达975 ％,COD为957%.并用XRD、TEM、 UV-Vis和XPS等手段进行了表征,iO2以锐钛矿型形式存在.比较了不同制备方法制得的TiO2/C复合催化剂,得出超临界干燥法制备的光催化剂具有粒径小,比表面积大,分散性好,光催化活性高等特点.     

Preparation and properties of polysulfone/TiO2 composite ultrafiltration membranes

The influence of inorganic filler TiO₂ nanoparticles on the morphology and properties of polysulfone (PS) ultrafiltration membranes was investigated. PS/TiO₂ composite membranes were prepared by a phase‐inversion method. TiO₂ nanoparticles modified by sodium dodecyl sulfate were uniformly dispersed in an 18 wt % PS casting solution. The addition of TiO₂ resulted in an increase in the pore density and porosity of the membrane skin layer. The pore size distribution changed from the log‐normal distribution to the bimodal distribution because of the presence of TiO₂ nanoparticles, and some large pores were observed when the concentration of the filler was over 3 wt %. The skin layer was gradually thickened; meanwhile, the morphology sublayer changed from macrovoids to spongelike pores, in comparison with PS membranes without the filler. The addition of TiO₂ also induced increases in the hydrophilicity, mechanical strength, and thermal stability. The ultrafiltration experiments showed when the concentration of TiO₂ was less than 2 wt %, the permeability and rejection of the membrane was enhanced and then decreased drastically with a higher filler concentration (>3%). © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 879–887, 2006     

Plasma treatment of carbon fiber on the tribological property of polyimide composite

The effect of different ratios of carbon fiber (CF) reinforcing polyimide (PI) and surface treatment of CF on the microstructure and wear resistance of surface layers was studied. The increase of CF content led to a gradual increase in the Interlaminar shear strength (ILSS) values, and the maximum ILSS value arises when the CF content is 15 vol%, with an improvement of 13.45% compared to virgin CF composites. The increased interfacial adhesion could be contributed mainly to the presence of branched PI at the interface region. SEM of the worn surface confirms that the plasma treatment efficiently improves the interfacial adhesion of CF/PI composite. Copyright © 2017 John Wiley & Sons, Ltd.     

The mechanical properties of plasma‐treated carbon fiber reinforced PA6 composites with CNT

The aim of this work is the evaluation of the effects of plasma treatment and the addition of CNT on the mechanical properties of carbon fibre/PA6 composite. A powder impregnation process with integrated inline continuous plasma of carbon fibers was used to produce CF/PA6 composite. CF/PA6 composite was processed into test laminates by compression moulding, and interface dominated composite properties were studied. The tensile and impact strength of composites containing CNT and plasma‐treated carbon fibres improved obviously. The tensile strength of nanocomposite largely increases with the increasing of the CNT content and then decreases when the CNT content is over 2%. The hydroxyl groups of the fibers surface are in favor of the wettability of carbon fibers by the polar matrix resin, which is resulting in a further interaction of the fiber surface with the curing system of the matrix resin.     

The interfacial feature of thermoplastic polystyrene composite filled with nitric acid oxidized carbon fiber

The quality of interfacial interaction is dictated by the surface chemistry of the carbon fibers and the composition of the matrix. The composition of polystyrene was modified by the addition of maleic anhydride (MAH) grafted polystyrene. The surface properties of the various matrix formulations were characterized by contact angle. Carbon fibers were modified by oxidation in nitric acid. The surface composition of the carbon fibers was characterized. The interaction between modified polystyrene and the carbon fibers was studied by single fiber pull‐out tests. The best adhesion behavior was achieved between polystyrene containing grafted MAH and nitric acid oxidation carbon fibers. The addition of MAH‐grafted polystyrene to the unmodified polystyrene caused the interfacial shear strength (IFSS) to increase. The IFSS of this fiber‐matrix combination allowed for the full utilization of the tensile strength of polystyrene. Copyright © 2009 John Wiley & Sons, Ltd.     

浓度梯度分布的镍和氮共掺杂TiO2光催化剂的制备和表征

以TiCl4为钛前驱体, 氨水和氯化镍为掺杂离子给体, 采用沉淀和层层浸渍相结合的方法制备了氮、镍共掺杂TiO2光催化剂. 采用X射线衍射(XRD)、氮气吸附-脱附、X射线光电子能谱(XPS)、紫外-可见漫反射吸收光谱(UV-Vis)等现代表征方法对催化剂的晶体结构、微结构、掺杂基团和光谱性质进行了表征. XRD和氮吸附-脱附分析结果表明, 氮、镍共掺杂TiO2为单一锐钛矿相, 具有介孔结构. XPS谱证实掺杂的氮和镍分别以NOx和Ni2O3及NiO的形式存在, 且镍在共掺杂表面的浓度高于体相中的浓度, 在扩散方向上存在浓度梯度分布. 4-氯酚的降解实验结果表明, 浓度梯度分布镍和氮共掺杂TiO2的紫外光-可见光催化活性均高于均相共掺杂TiO2、单掺杂和未掺杂TiO2的催化活性. 其原因是掺杂的氮以NOx形式存在, 使催化剂的感光范围拓展至可见光区; 而掺杂的镍维持了半导体体系的电荷平衡, 有效抑制了Ti3+的产生. 同时掺杂的镍在催化剂中存在浓度梯度分布, 减少了光生电子和空穴的复合几率, 提高了催化剂的光催化活性.