Toxikologische Prüfung eines Geschirrspülmittels

Toxicological Examination of a Dish-Washing Agent The acute toxicity, emetic action and tolerance of a commercial dish-washing agent were investigated in mice, rats and dogs, whereby the animals were subjected to repeated ingestion of this substance. Furthermore, the toxic actions on embryo and the effect on fertility were tested. The preparation showed a very low acute toxicity and it caused nausea in dogs given moderate doses. Repeated intake of high doses was tolerated by rats. No signs of intolerance were shown by dogs which received subemetic doses. No effect of the preparation on fertility and embryo-development could be detected. It can be concluded from these results that the application of the preparation as dish-washing agent does not involve any risk to the health.     

玻璃光纤制品医用消毒试验分析

通过对玻璃光纤制品进行常规的4种医用消毒试验，发现干热法和湿热法医用消毒对玻璃光纤制品基本无影响，但药物法和辐射法消毒则对玻璃光纤制品产生出不同程度损伤。试验发现，可以通过改变光学玻璃材料或增加表面增强技术等方法适应不同医用消毒方法，并提出了制造适合医用消毒的化学稳定性强的环保型光学玻璃、耐辐射光学玻璃、可拓宽玻璃光纤光传输波段光学玻璃以及研究玻璃光纤束表面增强技术的必要性和时代性。     

Effect of damage by hydroxyl generation on strength of silica fibers

When water diffuses into silica glass, a chemical reaction between the water and the glass damages the ring structure of the glass, causing a reduction in the Young's modulus, a lowering of the intrinsic strength and a reduction in the crack‐growth resistance of the glass. In the absence of swelling of the glass within the water penetrated zone, the damage caused by hydroxyl group generation will have no effect on the strength of the glass fibers, provided the water‐affected surface zone is much thinner than the bulk material. In contrast, swelling stresses within the water penetrated zone at the fiber glass surface will increase the strength of the glass fibers.     

Experimental investigation on foam formation through deformable porous media

Foam formation in porous media is a topic of growing scientific and industrial interest due to its range of applications, from daily life consumer products to oil recovery. Despite the work done so far on foams flowing through complex structures, such as rigid porous media, this subject still needs to be fully elucidated. An additional complexity to the problem arises when the porous medium is deformable, a situation which has only been faced, to our knowledge, from a modelling point of view. In this work, the investigation of foam formation in deformable porous media is carried out by using commercial sponges as a deformable porous media system, with special emphasis on the effect of confinement on foam bubble size distribution. Foam is formed by wetting the sponge with an aqueous surfactant solution and then squeezing the sponge either between two glass cover slides or between a plastic net and a cover slide. Our experimental data reveal that the latter system allows the formation of drier foams (ie, with lower liquid fraction, f_L < 0.3), more similar to the ones obtained in dish-washing applications. Moreover, the effect of sponge type, in terms of material and microstructure, on final foam is presented. Our results are of potential interest for the optimization of foams in complex structures, such as in deformable porous media.     

High wear-resistance characteristic of boron-doped nano-polycrystalline diamond on optical glass

Boron-doped nano-polycrystalline diamond (B-NPD) uniformly containing boron atoms in the diamond lattice has been successfully produced by direct conversion sintering under ultra-high pressure and high temperature using boron-doped graphite as a starting material, and its wear properties on optical glass materials have been investigated. The chemical wear of B-NPD sliding on glass was highly suppressed under sliding conditions where undoped NPD is worn considerably by chemical reaction with glass because the frictional resistance of NPD decreased and its sliding performance was improved by adding boron. In addition, because B-NPD has electrical conductivity, tribo-microplasma damages attributed to frictional electrification were not observed. Thus, the wear resistance of B-NPD on glass materials was improved greatly in comparison with that of undoped NPD. These results indicate that B-NPD has outstanding potential as a cutting tool material for high-performance and high-precision cutting on various types of glass, nonconductive ceramics and rigid plastics which are difficult to cut by conventional diamonds because of tribo-chemical wear or tribo-electrical wear.     

A comparison of surfactants derived from alcohols based on petrochemical and oleochemical sources

Samples of lauryl-range alcohols derived from palm kernel oil, coconut oil and ethylene (Ziegler) were derivatized into alcohol sulfates and alcohol ether sulfates (2 moles of ethylene oxide adduct). Physical properties and performance characteristics for earch surfactant were evaluated both individually and in light-duty liquid (LDL) dish-washing formulations. The slight differences observed in the physical and performance properties of the surfactants and their formulations were assignable to slight differences the individual alcohol, alcohol sulfate and alcohol ether sulfate samples employed in this study. The magnitude and type of variation found in the samples resulted from normal production variation and not from any properties inherent to the nature of the alcohol source. We therefore conclude that alcohol sulfates, alcohol ether sulfates and LDLs formulated from them exhibit identical physical property and performance characteristics, regardless of whether the original alcohol was manufactured from petrochemical or eleochemical sources.     

Impact damage sensing in glass fiber reinforced composites based on carbon nanotubes by electrical resistance measurements

In this article, we report an interesting employment of multi‐walled carbon nanotubes as a filler in the epoxy matrix of a glass fiber reinforced composite (FRP). The intrinsic electrical conductivity of carbon nanotubes made the development of a nanocomposite with enhanced electrical properties possible. The manufactured nanocomposite was subsequently employed in the production of a glass FRP. Due to the high aspect ratio of carbon nanotubes, very small amounts of these particles were sufficient to modify the electrical properties of the obtained glass fiber composites. Basically, a three‐phases material was developed, in which two phases were electrically insulating—epoxy matrix and glass fiber—and one phase highly conductive, the carbon nanotubes. The main goal of this study was to investigate the possibility of developing a glass fiber reinforced nanocomposite (GFRN), which is able to provide measurable electrical signals when subjected to a low‐velocity impact on its surface. Following this goal, the drop in the mechanical performance of the composite was evaluated before and after the impact. At the same time, the variation in its electrical resistance was measured. The results have shown that it is possible to associate the increase in electrical resistance of the composite with the formation of damages caused by impact. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Low‐velocity impact response in composite plates embedding shape memory alloy wires

In this work, the behavior of hybrid composite plates, embedding superelastic shape memory alloy (SMA) wires, subjected to low‐velocity impacts was studied. The impact experiments were performed on glass reinforced thermoset composite plates containing 1% by volume of superelastic thin wires (0.1 mm of diameter) of a SMA. The specimens were impacted with instrumented drop weight impact equipment: different dropping heights were used to attain impact energies from 1 to 500 J. The shape and size of damaged area were analyzed using two nondestructive inspection methods: (1) light scattering under back illumination was used to observe minor damages such as matrix cracks and fiber matrix debonding and (2) the size and shape of large damages such as delaminations were evaluated by infrared thermography. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

A lead-free non-ferroelectric piezoelectric glass-ceramic for high temperature surface acoustic wave devices

A piezoelectric glass-ceramic containing Sr₂TiSi₂O₈ crystals is synthesized and used to develop a SAW device tested up to 950 °C. This device consists of an input IDT that generates the wave and an output IDT that converts it into a measurable electrical signal. The evolution of amplitude and frequency of the output signal is recorded. This study highlights that the glass-ceramic remains able to generate and propagate SAW up to 950 °C. The variations of the signal between room temperature and 950 °C are discussed with respect to the thermomechanical properties of the glass-ceramics. The softening of the residual glass above its Tg increases the signal’s amplitude thanks to the relaxation of the stresses. At higher temperatures, the low residual glass viscosity causes the damping of the SAW. Below Tg, the variations of the signal are explained by the thermal expansion mismatch between the crystals and the glass, inducing tensile stresses and damages.     

环氧树脂/玻璃纤维/碳纤维混杂复合板低速冲击及损伤检测

为研究玻璃纤维(G)铺层的位置对碳纤维(C)复合板冲击损伤程度的影响,分别在15 J和25 J冲击能量的条件下,采用落锤式冲击试验机对[CC]2s、[CCCG]s、[GCCC]s、[CCGC]s 4种复合材料分别进行冲击实验,得出接触力、能量和位移分别随着时间变化的曲线;然后采用水浸式超声波C扫系统对冲击后的复合板进行...     

Differences in surface failure modes of soda lime silica glass under normal indentation versus tangential shear: A comparative study on Na+/K+-ion exchange effects

The effects of exchanging Na⁺ with K⁺ on the mechanical and mechanochemical properties of a soda lime silica (SLS) glass were investigated. It is known that replacing smaller modifier ions with bigger ions in the silicate glass network, at temperatures below the glass transition (T_g), produces a compressive stress in the subsurface region that enhances resistance to mechanical damages. This study found that when Na⁺ ions in SLS are exchanged with K⁺ ions at 400°C, the hardness, indentation fracture toughness, and crack initiation load of the surface are increased, which is consistent with the chemical strengthening effect. However, the resistance to mechanochemical wear in a near-saturation humidity condition (relative humidity RH = 90%) is deteriorated. When K⁺ ions are exchanged back with Na⁺ ions at 350°C, the wear resistance in high humidity conditions is recovered. These results indicate that the improvement of mechanical properties under indentation normal to the surface is irrelevant with the resistance to mechanochemical wear under tangential shear at the surface. Based on the analysis of the surface chemical composition, silicate network structure, and hydrogen-bonding interactions of hydrous species in the subsurface region, it is proposed that the leachable Na⁺ associated with non-bridging oxygen and subsurface hydrous species in the silicate network play more important roles in the mechanochemical wear of SLS at high RH.     

Improved hydrothermal aging performance of glass fiber-reinforced polymer composites via silica nanoparticle coating

The long-term exposure to a hot and humid environment severely damages the bonding integrity of fiber-reinforced polymer composites and thus significantly degrades their mechanical performances. In this work, we aim to develop an improvement procedure for effectively enhancing the bonding strength in glass fiber-reinforced polymers (GFRPs). Glass fibers were coated with a thin layer of silica nanoparticles of different concentrations by the use of the evaporative deposition method. Micromorphological comparisons in terms of scanning electron microscope imaging demonstrate significant improvements on the surface roughness of glass fibers. With the coated glass fibers, GFRP composite laminates were designed, molded through the vacuum-assisted resin infusion technique, and experimentally tested for quantitatively studying their hydrothermal aging performance. The water absorption tests conducted for three exposure temperatures suggest that both the water diffusion rate and the equilibrium water content can be effectively reduced due to the introduction of the silica coating. With increased exposure temperatures, however, the desired reductions become much less significant. A so-called water-channel diffusion mechanism along fiber/resin interfaces was proposed to explain the coupling effects of silica coating and exposure temperature. Reductions of water diffusion rate and equilibrium water content were expected to slow down the hydrothermal aging performance of GFRPs. For this purpose, both uniaxial tensile test and three-point bending test were subsequently performed on GFRP specimens that have been subjected to different coating concentrations, exposure temperatures, and exposure durations. When compared with untreated GFRP specimens, both experiments demonstrate that the residual strength and stiffness can be effectively promoted through coating a thin layer of silica nanoparticles on glass fiber surfaces. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48652.     

In vitro Cytotoxicity,Apoptotic and Hemolysis Assay of Kalsilite‐Based Glass Ceramics for Dental Veneering Application

Nanocrystalline kalsilite material was synthesized via a gel‐trapped coprecipitation for dental veneering applications. The prepared kalsilite powder was further mixed with a separately processed low temperature frit (LTF), in different weight ratio to optimize its coefficient of thermal expansion (CTE). These mixes were analyzed for their flexural strength and surface morphology. The cytocompatibility of mixes was investigated with reference to their effect on human buccal epithelial cells (SCC‐25). The flexural strength and CTE values of prepared kalsilite have been found to be comparable to the values obtained for a commercial opaque VMK 95 1M2 (product no. B333250; VITA Zahnfabrik H. Rauter GmbH KG Postfach 1338 D‐79704 Bad Sackingen, Germany). This confirmed the feasibility of prepared kalsilite material for dental veneering application. Kalsilite glass‐ceramic materials caused moderate levels of apoptosis in SCC‐25 cells at higher concentrations and were also tolerable by human RBC as evaluated from hemolytic assay. Human buccal epithelial cells were tolerant to kalsilite glass‐ceramic materials at lower concentrations although higher concentration (500 μg/mL) caused moderate damages in proliferative capacity of SCC‐25. The improved mechanical and biological properties of the prepared kalsilite confirmed its potential use in dental veneering.     

Long term ageing of polyamide 6 and polyamide 6 reinforced with 30% of glass fibers: physicochemical,mechanical and morphological characterization

Hygrothermal ageing of polyamide 6 (PA6) and polyamide 6 reinforced with 30 wt% of glass fibers (PA6GF30) was undertaken. Immersion was conducted in distilled water at 90 °C and 100% relative humidity (RH) for up to 80 days (1920 h). Results revealed a noteworthy decrease either in glass transition temperature T_g or in tensile properties, at early stage of ageing, for both studied materials. This decline was mainly caused by the plasticization effect of water and the weakness of the interfacial interactions leading as a consequence to a loss of adhesion between fiber and matrix. Afterwards, physical and mechanical properties decrease monotonically testifying the occurrence of exhaustive damages and chemical reaction phenomena. Such phenomena were yellowing and crazing formation which were observed for both materials after 1920 h of conditioning. The former is caused by the thermo- oxidation whereas the latter results from the release of internal stresses induced by water sorption. These chemical reactions were monitored by infrared spectroscopy. Thus, an increase of the free N-H stretch and the carbonyl groups (imides) was noted. Accordingly, it seems that long term immersion in distilled water at high temperature induces chemical reactions which indicate the severity of the damage.     

聚合物热黏弹塑性变形微热压成型机理的数值模拟研究

研究了聚甲基丙烯酸甲酯（PMMA）超疏性阵列圆柱微结构特征功能表面的微热压成型技术,通过模拟研究了成型工艺参数对成型过程的影响规律,揭示了其热黏弹塑性变形充填流动机理,明晰了关键调控参数。结果表明,基片材料的弹性模量、成型温度和压力是影响充填成型的关键调控参数,成型压力和变形应力与成型温度呈负关联关系,而充填高度与成型温度呈正关联关系;提高成型温度至高于基片材料的玻璃化转变温度（Tg）,使基片处于黏弹性高弹态,易使基片快速产生明显的热黏弹塑性变形,且可使成型压力和变形应力趋于最小值,这有利于基片避免断裂损伤并加速充模流动。     

Boron nitride nanosheets reinforced glass matrix composites

The effect of reinforcing boron nitride nanosheets (BNNSs) on the mechanical properties of an amorphous borosilicate glass (BS) matrix was studied. The BNNSs were prepared using liquid exfoliation method and characterised by transmission electron microscopy, scanning electron microscopy and X-ray diffraction (XRD) analysis. The average length was ～0.5?μm, and thickness of the nanosheets was between 4 and 30 layers. These BNNSs were used to prepare BS-BNNS composite with different loading concentrations of 1, 2.5 and 5 mass-% (i.e. 1.395, 3.705 and 7.32 vol.-%). Spark plasma sintering (SPS) was used to densify these composites to avoid structural damages to the BNNSs and/or crystallisation within the composite sample during high temperature processing. The BNNSs were found to be evenly distributed in the composites matrix and were found to be aligned in an orientation perpendicular to the direction of the applied force in SPS. The mechanical properties including fracture toughness, flexural strength and elastic modulus were measured. Both fracture toughness and flexural strength increased linearly with increasing concentration of BNNSs in BS glass. There was an enhancement of ～45% in the fracture toughness (1.10?MPa.m^1/2) as well as flexural strength (118.82?MPa) with the addition of only 5 mass-% loading of BNNSs compared to BS glass (0.76?MPa.m^1/2; 82.16?MPa). The toughening mechanisms developed in the composites because of the reinforcement of BNNSs were thoroughly investigated.     

In-field reparation of the damaged coatings for C/C composites

Protective coatings are critical to the successful application of the carbon/carbon (C/C) composites in the thermal protection systems of space vehicles. The damages of such coatings during installation and operation would threaten the safety of flight. In this contribution, an in-field technology based on a multilayer structure was developed to repair the damaged coatings of C/C composites. The multilayer structure contains a silicon buffer inner layer, a mullite heat-resistant middle layer and a borosilicate glass outer layer. The oxidation tests in air at 1300 °C and 1500 °C indicated that the weight loss of the repaired samples was greatly reduced compared with that of the damaged ones. The plasma wind tunnel tests for both repaired and damaged coatings further demonstrated that the multilayer structure could effectively protect the damaged composites from ablation in oxidation environments.     

Damage characterization of repeatedly impacted glass fiber reinforced polyester‐armor steel composites with cone beam computed tomography technique

This article utilizes the characterization of single and repeated low velocity impact damage behavior of glass fiber reinforced polyester (GFRP) armor steel composite. Cone beam computed tomography technique (CBCT) was used for damage assessment. Impact energies, maximum loads and the permanent deflection of GFRP, armor steel composites are determined with instrumented drop weight impact test machine. The repeated impact performance and damage resistance were evaluated. On the other hand, preliminary single impact loading tests also performed in order to find the energy levels, which were ranged fully elastic energy level to perforation energy level for GFRP, armor steel composites. Additionally, CBCT was used to provide a novel, multiscale approach for assessing impact damage. Deformation areas of both single and repeatedly impacted GFRP, armor steel composites were assessed three‐dimensionally by CBCT. An innovative approach was used to visualize the internal damages. POLYM. COMPOS., 37:583–593, 2016. © 2014 Society of Plastics Engineers     

Experimental investigation into glass fiber/epoxy composite laminates subjected to single and repeated high-velocity impacts of ice

Many engineering components in aerospace structures which are made from polymer composite materials are often damaged during service life due to hail ice and bird impact. This study examines the damage which may be incurred by a single and repeated high-velocity impact of 11.7 g cylindrical-shaped ice on glass fiber/epoxy laminated composite panels carried out on a 20-mm diameter smooth barrel gas gun. The laminates were made from E-glass fiber/epoxy resin with 0/90, ±45, chopped strand mat (CSM) and unidirectional fiber orientation and in different stacking sequence. The impact velocity was in the range of 130–140 m/s and the resulting damage extension zones from ice projectile impacts were measured. Damage extension was successfully identified in all specimens subjected to high-velocity ice projectile impact. Results showed specimens with ±45 orientation and CSM fiber exhibited the lowest damage extension. The results also revealed that specimens with plain weave 0/90 lay-up of glass woven roving show the highest damage extension. Extended damages were observed in composite panels under repeated ice projectile impacts. Study of the stacking sequence effect indicated significant role played by presence of ±45 reinforcement in reducing the damage extension in the laminated plates. Delamination constituted the major damage mechanism for most specimens tested followed by matrix and fiber fracture.     

基于NOL环的高性能纤维与环氧树脂的匹配性研究

纤维与树脂的界面对复合材料的整体力学性能有着显著的影响。基于NOL环的宏观力学测试一般被用来反映复合材料的界面粘结性能,因此适用于评价纤维与树脂之间的宏观力学性能匹配性。为了探究高性能碳纤维T700SC、T800HB及高强玻璃纤维与环氧树脂的宏观力学性能匹配性,本研究首先根据GB/T 1458—2008国家标准制备NOL环试样,再借助NOL环的拉伸和层间剪切强度测试分析了高性能纤维与环氧树脂不同匹配组合宏观力学性能差异的原因,并寻找出最佳匹配组合。结果表明:玻璃纤维与环氧树脂的界面存在最佳的粘结强度,而且不同粘结强度导致拉伸强度和破坏机理不同,而碳纤维复合材料界面性能较差,容易分层破坏;T800HB与环氧树脂的宏观力学匹配性优于T700SC,环氧树脂力学性能、碳纤维的表面微观结构与性质以及环氧树脂与碳纤维之间的相互作用关系是影响界面粘结性能的根本原因。该研究在高性能纤维单向复合材料的材料选择与设计方面具有现实意义。