Recently the manufacture of epoxy coating and flooring materials begun to be under strong pressure to use more environmentally friendly raw materials in its composition.First tendency to reduce of solvents and diluent...Recently the manufacture of epoxy coating and flooring materials begun to be under strong pressure to use more environmentally friendly raw materials in its composition.First tendency to reduce of solvents and diluents contained in the materials appeared at the end of 90´s.This situation was supported by the Council of Europe in 2004 to reduce VOC emissions to zero till 2020.Solvent materials were thus largely replaced by solvent free materials from which the volatile substances are not released into the air.But pressure continued to increase,and over the past decade began to take centre stage water-based epoxy.On the Czech market solvent based material is still occasionally used,but predominant are solvent free materials.There are no commonly used materials containing wastes as fillers in new water-borne and solvent-free epoxy materials.Characteristics identification of the waste material as a potential filler is a set of properties that determine the limits of secondary raw materials or waste as a filler.This paper describes the basic characteristics which must be selected to meet the requirements,to affect negatively the workability,sedimentation,properties and behavior of the final floor system.Some materials must comply with special requirements,such as resistance to chemicals,etc.Next part of paper talks about utilization of polymer floors and their mechanical properties.展开更多
With excellent energy densities and highly safe performance,solidstate lithium batteries(SSLBs)have been hailed as promising energy storage devices.Solid-state electrolyte is the core component of SSLBs and plays an e...With excellent energy densities and highly safe performance,solidstate lithium batteries(SSLBs)have been hailed as promising energy storage devices.Solid-state electrolyte is the core component of SSLBs and plays an essential role in the safety and electrochemical performance of the cells.Composite polymer electrolytes(CPEs)are considered as one of the most promising candidates among all solid-state electrolytes due to their excellent comprehensive performance.In this review,we briefly introduce the components of CPEs,such as the polymer matrix and the species of fillers,as well as the integration of fillers in the polymers.In particular,we focus on the two major obstacles that affect the development of CPEs:the low ionic conductivity of the electrolyte and high interfacial impedance.We provide insight into the factors influencing ionic conductivity,in terms of macroscopic and microscopic aspects,including the aggregated structure of the polymer,ion migration rate and carrier concentration.In addition,we also discuss the electrode-electrolyte interface and summarize methods for improving this interface.It is expected that this review will provide feasible solutions for modifying CPEs through further understanding of the ion conduction mechanism in CPEs and for improving the compatibility of the electrode-electrolyte interface.展开更多
PLA composites containing biomass fillers from the three herbaceous plants such as reed,wheat stalk,and coco-nut fiber with length and diameter at the scale of several millimeters were prepared without using additives...PLA composites containing biomass fillers from the three herbaceous plants such as reed,wheat stalk,and coco-nut fiber with length and diameter at the scale of several millimeters were prepared without using additives.The reinforcement effect on the properties of PLA/biomass filler composites is investigated.The research results show that the PLA/biomass filler composites exhibit good stiffness,flexural strength,and impact toughness.Among the three kinds of biomass fillers,reed reinforced PLA composites show optimal mechanical properties.When filled with 40%–50%reed,the flexural moduli of the composites are over 7000 MPa.Flexural strength retains at the same level of pure PLA.The notch impact strength reaches to 4.50±0.73 kJ/m^(2),which is 2.06 times higher than that of pure PLA.Furthermore,the introduction of biomass fillers increases the crystallization ability of PLA and does not increase the water absorption of the composites.This research demonstrated that PLA composites prepared with biomass fillers from the herbaceous plants(namely herb plastic composites,HPCs)is a material with good comprehensive mechanical properties while retaining the intrinsic particularity of biological sources.展开更多
The compaction quality of subgrade filler strongly affects subgrade settlement.The main objective of this research is to analyze the macro-and micro-mechanical compaction characteristics of subgrade filler based on th...The compaction quality of subgrade filler strongly affects subgrade settlement.The main objective of this research is to analyze the macro-and micro-mechanical compaction characteristics of subgrade filler based on the real shape of coarse particles.First,an improved Viola-Jones algorithm is employed to establish a digitalized 2D particle database for coarse particle shape evaluation and discrete modeling purposes of subgrade filler.Shape indexes of 2D subgrade filler are then computed and statistically analyzed.Finally,numerical simulations are performed to quantitatively investigate the effects of the aspect ratio(AR)and interparticle friction coefficient(μ)on the macro-and micro-mechanical compaction characteristics of subgrade filler based on the discrete element method(DEM).The results show that with the increasing AR,the coarse particles are narrower,leading to the increasing movement of fine particles during compaction,which indicates that it is difficult for slender coarse particles to inhibit the migration of fine particles.Moreover,the average displacement of particles is strongly influenced by the AR,indicating that their occlusion under power relies on particle shapes.The dis-placement and velocity of fine particles are much greater than those of the coarse particles,which shows that compaction is primarily a migration of fine particles.Under the cyclic load,the interparticle friction coefficientμhas little effect on the internal structure of the sample;under the quasi-static loads,however,the increase inμwill lead to a significant increase in the porosity of the sample.This study could not only provide a novel approach to investigate the compaction mechanism but also establish a new theoretical basis for the evaluation of intelligent subgrade compaction.展开更多
Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H2O2) and distilled...Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H2O2) and distilled water(H2O). The functional groups on the surface of CNTs, changes in nanotube structure and morphology were characterized by Fourier transform infrared spectroscopy(FT-IR), Raman Spectroscopy, and transmission electron microscopy(TEM). It shows that hydroxyl(OH·) is successfully introduced. The surface defects of modified CNTs were obviously higher than those of original CNTs, and the degree of agglomeration was greatly reduced. Thermal conductivity of the composites was tested by protection heat flow meter method. Compared with unmodified CNTs/CB filling system, the thermal conductivity of hybrid composites is improved by an average of 5.8% with 1.5 phr(phr is parts per hundred rubber) of hydroxyl CNTs and 40 phr of CB filled. A three-dimensional heat conduction network composed of hydroxyl CNTs and CB, as observed by TEM, contributes to the good properties. Thermal conductivity of the hybrid composites increases as temperature rises. The mechanical properties of hybrid composites are also good with hydroxyl CNTs filled nanocomposites;the tensile strength, 100% and 300% tensile stress are improved by 10.1%, 22.4% and 26.2% respectively.展开更多
The pyrolytic process of polycarbosilane (PCS) with active fillers (Ti, TiH 2, TiB 2, Cr, CrSi 2) is investigated. The ceramic yields with active fillers reach over 100% in N 2 atmosphere, and no shrinkage occurs when...The pyrolytic process of polycarbosilane (PCS) with active fillers (Ti, TiH 2, TiB 2, Cr, CrSi 2) is investigated. The ceramic yields with active fillers reach over 100% in N 2 atmosphere, and no shrinkage occurs when 12vol% Ti, or 4vol% Cr, or 3vol% CrSi 2 is added into PCS. XRD patterns indicate that metal carbides and nitrides form by reacting with gaseous evolution and N 2.展开更多
Polymer electrolyte membranes based on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDFHFP) with and without different types of micro inorganic fillers were prepared by phase-inversion process. Morphologies...Polymer electrolyte membranes based on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDFHFP) with and without different types of micro inorganic fillers were prepared by phase-inversion process. Morphologies, porosities and electrochemical properties 'of the as-prepared membranes were investigated by means of scanning electronic microscopy (SEM), PC (propylene carbonate) uptake and alternating current (AC) impedance technique. Compared with other membranes, the membrane with micro SiO2 filler shows a dense morphology so that its PC uptake is the highest, namely, 339 %. The membrane filled with micro TiO2 exhibits good electrochemical performances: the ion conductivity is as high as 1.1 × 10^-3 S/cm at 18 ℃, which can meet the demand of lithium ion batteries. Moreover, its initial charge-discharge efficiency exceeds 89 %. The composite membranes with micro SiO2, TiO2 and Al2O3 are more suitable for the utilization in lithium ion batteries due to better cycle.ability, whereas the battery assembled with the blank membrane containing no inorganic fillers encounters a short circuit after the 5th cycle.展开更多
The objective of this paper was to develop a comprehensive evaluation method and index to evaluate the performance of sealants and fillers for cracks in asphalt concrete pavements using the method of principal compone...The objective of this paper was to develop a comprehensive evaluation method and index to evaluate the performance of sealants and fillers for cracks in asphalt concrete pavements using the method of principal component analysis. The performance experiments including cone penetration, softening point, flow, resilience and tension at low temperature respectively were conducted by reference of ASTM D5329 for eight sealants and fillers often used in China. There by a principal component model was developed and weight of every index was calculated. The experimental results show that there are significantly different performances for sealants and fillers often used in China. Principal component analysis is an objective method that evaluates and selects the performance of sealants and fillers for cracks in asphalt concrete pavements.展开更多
The presents preparation and characterization of different types of lignocellulosic fillers(pine wood sawdust/walnut shell flour/black rice husk powder) reinforced polypropylene composites were presented. The effect o...The presents preparation and characterization of different types of lignocellulosic fillers(pine wood sawdust/walnut shell flour/black rice husk powder) reinforced polypropylene composites were presented. The effect of MAPP as coupling agent(4 wt%) on the physical and mechanical properties was also investigated. Polypropylene composites were prepared at different rates of filler/matrix(wt%) by using extrusion(for melt blending) and hot compression molding process. Maximum values of tensile and flexural strength were obtained as 26.1 and 43.4 MPa, respectively, whereas the elongation at break value was 4.11% at 10% pine wood sawdust reinforced PP. Tensile and flexural modulus of composites reached the maximum values as 3855 and 3633 MPa with the composite of 30% walnut shell flour reinforced PP. Characterization of composites was carried out by using tensile test, flexural test, FT-IR, and SEM.展开更多
The flexural strengths and oxidative resistant properties of the ceramics derived from polycarbosilane and active fillers (Ti, TiH 2, TiB 2, Cr, and CrSi 2) were measured and characterized. The introduction of acti...The flexural strengths and oxidative resistant properties of the ceramics derived from polycarbosilane and active fillers (Ti, TiH 2, TiB 2, Cr, and CrSi 2) were measured and characterized. The introduction of active fillers enhances slightly the flexural strengths, and further densification is required to obtain higher strengths. The oxidative resistant behaviors of the specimens with active fillers are, by means of weight gain in air, poorer compared with those without active fillers.展开更多
The surface of calcium carbonate(CaCO_3)particles was modified with stearic acid(SA)and the chemical structures of the product were characterized by FT-IR analysis.The interaction between polydimethylsiloxane(PDMS)and...The surface of calcium carbonate(CaCO_3)particles was modified with stearic acid(SA)and the chemical structures of the product were characterized by FT-IR analysis.The interaction between polydimethylsiloxane(PDMS)and CaCO_3 fillers with different surface character was investigated by means of dynamic rheological and bound rubber tests for uncured compounds and mechanical properties measurements for the corresponding vulcanites.The results of dynamic tests indicate that with the increase of SA mass fraction...展开更多
Different types of carbon-silica fillers were prepared via pyrolysis-cum-water vapor of waste green tires tread and impregnation method. Dual phase fillers have been characterized by energy dispersive X-ray (EDX) spec...Different types of carbon-silica fillers were prepared via pyrolysis-cum-water vapor of waste green tires tread and impregnation method. Dual phase fillers have been characterized by energy dispersive X-ray (EDX) spectroscopy in a scanning transmission electron microscope (STEM) or STEM-EDX. Phase distribution in hybrid fillers for rubber was investigated. The results achieved show that the conditions of obtaining influence the distribution and the location of the phases in the carbon-silica hybrid fillers as well as their most essential characteristics including specific area, oil absorption number, iodine adsorption number, ash content and others.展开更多
Preparation of hydroxyapatite(HA)through natural sources,such as fish scales or synthetic HA produced from the chemical reaction has been widely used as biomedical materials because HA is bioactive,non-toxic and osteo...Preparation of hydroxyapatite(HA)through natural sources,such as fish scales or synthetic HA produced from the chemical reaction has been widely used as biomedical materials because HA is bioactive,non-toxic and osteoconductive with a crystallographic structure almost similar to that of the bone mineral.In addition,HAwith particle size<10 microns is classified as common inorganic filler used to improve the mechanical properties and biocompatibility of polymer composites.The purpose of this review is to collect information related to HA,and to provide readers with information about synthesis methods,advantages of hydroxyapatite as biomaterial,biomedical applications of polymer/HA composites.展开更多
Plain weave woven glass fabric reinforced epoxy (G-E) composite filled with two different types of fillers namely graphite, silicon carbide (each 5 and 10 wt%) was fabricated by hand lay-up method and compressed using...Plain weave woven glass fabric reinforced epoxy (G-E) composite filled with two different types of fillers namely graphite, silicon carbide (each 5 and 10 wt%) was fabricated by hand lay-up method and compressed using hot press. These composites were investigated for their static mechanical properties such as tensile, flexural properties and impact strength as well as mode-I fracture toughness as per ASTM standards. Experimental results on mechanical properties indicate that the strength and the modulus in tensile and flexural mode for G-E composite increase with increasing filler loading. The unfilled G-E composite has the tensile strength of 305 MPa and increased to 404.2 MPa for 10 wt% silicon carbide. However, in three-point bend mode, addition of graphite in G-E showed the highest flexural strength as well as modulus. Mode-I fracture toughness test results indicated that the graphite filler loading improved the toughness of G-E composite. Selected failed samples under tensile, bending and mode-I fracture were examined using scanning electron microscope to identify the fracture features.展开更多
Amorphous filler Ti-Zr-Cu-Ni with better performance and higher melting point than the α → β phase transition temperature 882.5°C of TA2, is appropriate for joining TC and TB titanium alloys but not for TA t...Amorphous filler Ti-Zr-Cu-Ni with better performance and higher melting point than the α → β phase transition temperature 882.5°C of TA2, is appropriate for joining TC and TB titanium alloys but not for TA titanium alloys, with which the ductility of the joined base metal TA2 gets down. In this paper, Sn is added into Ti-Zr-Cu-Ni filler to reduce its melting temperature then to satisfy the joining temperature requirement, and the effects of the content of Sn on the microstructure of the alloy and brazing performance are investigated. The results show that, the Ti-Zr-Cu-Ni-Sn brazing foils still possess amorphous structure;the melting point of fillers is reducing with the increase of the Sn content;the joint gap that formed during brazing TA2 and Q235 using Ti-Zr-Cu-Ni-Sn foils is fully filled with continuous compact surface and smooth uniform fillet;the shear strength of the joint is raising with the increase of Sn content in brazing fillers and the strength reaches to 112 MPa when Sn content is 3%;adding more Sn, more brittle intermetallic compounds TiFe and TiFe2 are gathering to form cluster and the shear strength of the joint is reducing;the shear fracture always occurs in the center of the seam.展开更多
The aims of this study were to prepare natural hydroxyapatite from fish scales(FsHAp)for potential use as a filler in polymer.The FsHAp was prepared from Tilapia fish scales using thermal method.The FsHAp was milled f...The aims of this study were to prepare natural hydroxyapatite from fish scales(FsHAp)for potential use as a filler in polymer.The FsHAp was prepared from Tilapia fish scales using thermal method.The FsHAp was milled for 48 h and dried by spray method.The morphology was characterized using field emission scanning electron microscope(FESEM)which showed irregular shape of FsHAp particles with particle size around 7μm.The analysis of FsHAp was carried out using Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD)to confirm chemical structure of FsHAp.展开更多
High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The form...High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The formations of pools or pearls in HA fillers could be observed real time during injection. The plane of injection could be determined accurately, and there were no specimen manipulation artifacts. It was observed that HA gel fillers with differing production technologies showed distinct spread and distribution patterns in the periocular tissues on HRU examination. The authors used HRU to assess deep injections of CHAP-Hyaluronic Acid (CHAP-HA) fillers for midface lift. 10 patients who underwent bilateral midface deep injections using CHAP-HA filler were examined with HRU before and immediately after treatment, and in 2 weeks and one month later. The CHAP-HA appeared as hypoechoic densities within the preperiosteal plane in HRU. CHAP-HA adopted variable morphology within the tissue depending on individual tissue densities and the compliance of the tissues in the plane of injection. CHAP-HA was unidentifiable with surrounding tissue after one month in 13 of the 20 injection sites. HRU allows in vivo study of CHAP-HA injection behavior and could be a tool for further studies of HA-tissue reactions.展开更多
This study aims to determine the optimal quantity of fillers to add to hydraulic concrete and to assess the influence of these fillers on its rheological characteristics and mechanical properties. The characterization...This study aims to determine the optimal quantity of fillers to add to hydraulic concrete and to assess the influence of these fillers on its rheological characteristics and mechanical properties. The characterization of the aggregates shows that they meet the specifications for the formulation of hydraulic concrete according to the Dreux-Gorisse method. Normalizing the formula to the cubic meter enables to define the standard concrete. The cement content is 350 kg/m<sup>3</sup>. The mineral materials added to the concrete to increase its characteristics and properties are limestone, basalt, and sandstone fillers with a weight percent of 4%, 5%, and 3% respectively. Changes in concrete properties with the addition of fillers were determined through geotechnical tests. The results obtained show a decrease in the workability measured by slump test which returned 7.8 cm for the standard concrete sample, 7.2 cm with 5% of basalt, 7.3 cm with 4% of limestone, and 6.1 cm with 3% of sandstone. Regarding the bleeding, the results show that it decreases leading to a substantial improvement in stabilization reaching 26% with 5% of basalt fillers, 29% with 4% of limestone fillers, and 31% with 3% of sandstone fillers. The compressive strengths noted R<sub>c28</sub> at 28 days increases compared to that of the standard concrete, which is 31.5 MPa. They increase to 34.3 MPa with 5% of basalt fillers being 8.9%, 36.2 MPa with 4% of limestone fillers being 14.9%, and 36.8 MPa with 3% of sandstone fillers being 16.8%. Finally, the addition of fillers increases the degree of compaction values to 83.62% with 5% of basalt fillers, 84.2% with 4% of limestone fillers, and 84.34% with 3% of sandstone fillers.展开更多
Ti-Zr-Cu-Ni amorphous filler with good performance is suitable for joining TC and TB titanium alloy, but its melting temperature is higher than 882.5°C, the α→β phase transition temperature of TA2, which makes...Ti-Zr-Cu-Ni amorphous filler with good performance is suitable for joining TC and TB titanium alloy, but its melting temperature is higher than 882.5°C, the α→β phase transition temperature of TA2, which makes the ductility of TA2 fall and the microstructure of the joint coarse. In this paper, Ti-Zr-Cu-Ni amorphous filler was redesigned and optimized by using orthogonal experiment to obtain three easy-to-use Zr-Ti-Ni-Cu amorphous fillers with low melting points and good plasticity. The fast cooling equipment was used to fabricate the brazing filler foils to implement the braze welding of TA2 and Q235 with high frequency inductance. The results indicate that all the brazing foils are amorphous structure with lower melting temperature, for example, Zr52Ti22Ni18Cu8 filler’s is 538°C. The technical parameters in brazing welding are: welding temperature T = 800°C;heating electric current I =25 A;heating time t = 15 s and holding time t = 15 s, in the case of these conditions, the jointing head shear strength of TA2/Zr52Ti24Ni13Cu11/Q235 is 139 MPa. Fracture is mainly located in the brazing seam. The white brittle intermetallic TiFe, TiFe2 and enhancement TiC spread in the center zone of brazing seam.展开更多
Background: Semi-permanent fillers are among the most favorable fillers on the market. Through their unique mode of action and its associated lasting aesthetic effect, they take an exceptional position. Objective: To ...Background: Semi-permanent fillers are among the most favorable fillers on the market. Through their unique mode of action and its associated lasting aesthetic effect, they take an exceptional position. Objective: To compare the two semi-permanent fillers Poly-L-Lactic Acid (PLLA) and calcium hydroxylapatite (CaHA) in reference to the aesthetic result, patient satisfaction and side effects. Methods: Studies on side effects, patient satisfaction and aesthetic results after augmentation with semi-permanent fillers were analyzed. Results: Semi-permanent fillers seem excellently suited for the augmentation of very deep wrinkles particularly in the lower half of the face. In general, high patient satisfaction can be determined with both fillers. Here, the effect from the polylactic acid can be verified for up to two years while no effect could be verified already after one year in a majority of the patients augmented with CaHA. Short-term side effects such as bleedings or erythema in the region of the augmented area have been observed in both fillers during augmentation. The incidence of nodules and granulomas seems significantly higher in augmentations with PLLA compared to CaHA. Rare side effects such as an embolization of a blood vessel caused by the implant have been described for both fillers in case reports. Conclusion: Semi-permanent fillers are superbly suited for wrinkle augmentation. Which filler is the preferred one in what case depends strongly on the individual needs of the patient and the therapist’s experience.展开更多
基金supported by the project"OKTAEDR-partnership and building network."Project registration number is cz.1.07./2.4.00/31.0012.
文摘Recently the manufacture of epoxy coating and flooring materials begun to be under strong pressure to use more environmentally friendly raw materials in its composition.First tendency to reduce of solvents and diluents contained in the materials appeared at the end of 90´s.This situation was supported by the Council of Europe in 2004 to reduce VOC emissions to zero till 2020.Solvent materials were thus largely replaced by solvent free materials from which the volatile substances are not released into the air.But pressure continued to increase,and over the past decade began to take centre stage water-based epoxy.On the Czech market solvent based material is still occasionally used,but predominant are solvent free materials.There are no commonly used materials containing wastes as fillers in new water-borne and solvent-free epoxy materials.Characteristics identification of the waste material as a potential filler is a set of properties that determine the limits of secondary raw materials or waste as a filler.This paper describes the basic characteristics which must be selected to meet the requirements,to affect negatively the workability,sedimentation,properties and behavior of the final floor system.Some materials must comply with special requirements,such as resistance to chemicals,etc.Next part of paper talks about utilization of polymer floors and their mechanical properties.
基金the funding support from the National Key Research and Development Program of China(Grant Number 2021YFB2400300)National Natural Science Foundation of China(Grant Number 21875195,22021001)Fundamental Research Funds for the Central Universities(Grant Number 20720190040)。
文摘With excellent energy densities and highly safe performance,solidstate lithium batteries(SSLBs)have been hailed as promising energy storage devices.Solid-state electrolyte is the core component of SSLBs and plays an essential role in the safety and electrochemical performance of the cells.Composite polymer electrolytes(CPEs)are considered as one of the most promising candidates among all solid-state electrolytes due to their excellent comprehensive performance.In this review,we briefly introduce the components of CPEs,such as the polymer matrix and the species of fillers,as well as the integration of fillers in the polymers.In particular,we focus on the two major obstacles that affect the development of CPEs:the low ionic conductivity of the electrolyte and high interfacial impedance.We provide insight into the factors influencing ionic conductivity,in terms of macroscopic and microscopic aspects,including the aggregated structure of the polymer,ion migration rate and carrier concentration.In addition,we also discuss the electrode-electrolyte interface and summarize methods for improving this interface.It is expected that this review will provide feasible solutions for modifying CPEs through further understanding of the ion conduction mechanism in CPEs and for improving the compatibility of the electrode-electrolyte interface.
基金supported by“One Belt,One Road”Projects of China Academy of Sciences(174433KYSB20190082)Science and Technology Service Network Plan of China Academy of Sciences(KFJ-STS-QYZD-2021-16-002)+2 种基金Key Projects of Ningbo Public Welfare Science and Technology Plan(2021S020)Ningbo Natural Science Foundation(2021J196)Youth Innovation Promotion Association CAS(2017339).
文摘PLA composites containing biomass fillers from the three herbaceous plants such as reed,wheat stalk,and coco-nut fiber with length and diameter at the scale of several millimeters were prepared without using additives.The reinforcement effect on the properties of PLA/biomass filler composites is investigated.The research results show that the PLA/biomass filler composites exhibit good stiffness,flexural strength,and impact toughness.Among the three kinds of biomass fillers,reed reinforced PLA composites show optimal mechanical properties.When filled with 40%–50%reed,the flexural moduli of the composites are over 7000 MPa.Flexural strength retains at the same level of pure PLA.The notch impact strength reaches to 4.50±0.73 kJ/m^(2),which is 2.06 times higher than that of pure PLA.Furthermore,the introduction of biomass fillers increases the crystallization ability of PLA and does not increase the water absorption of the composites.This research demonstrated that PLA composites prepared with biomass fillers from the herbaceous plants(namely herb plastic composites,HPCs)is a material with good comprehensive mechanical properties while retaining the intrinsic particularity of biological sources.
基金This work was supported by the National Key R&D Program‘Transportation Infrastructure’project(No.2022YFB2603400).
文摘The compaction quality of subgrade filler strongly affects subgrade settlement.The main objective of this research is to analyze the macro-and micro-mechanical compaction characteristics of subgrade filler based on the real shape of coarse particles.First,an improved Viola-Jones algorithm is employed to establish a digitalized 2D particle database for coarse particle shape evaluation and discrete modeling purposes of subgrade filler.Shape indexes of 2D subgrade filler are then computed and statistically analyzed.Finally,numerical simulations are performed to quantitatively investigate the effects of the aspect ratio(AR)and interparticle friction coefficient(μ)on the macro-and micro-mechanical compaction characteristics of subgrade filler based on the discrete element method(DEM).The results show that with the increasing AR,the coarse particles are narrower,leading to the increasing movement of fine particles during compaction,which indicates that it is difficult for slender coarse particles to inhibit the migration of fine particles.Moreover,the average displacement of particles is strongly influenced by the AR,indicating that their occlusion under power relies on particle shapes.The dis-placement and velocity of fine particles are much greater than those of the coarse particles,which shows that compaction is primarily a migration of fine particles.Under the cyclic load,the interparticle friction coefficientμhas little effect on the internal structure of the sample;under the quasi-static loads,however,the increase inμwill lead to a significant increase in the porosity of the sample.This study could not only provide a novel approach to investigate the compaction mechanism but also establish a new theoretical basis for the evaluation of intelligent subgrade compaction.
基金Supported by the National Natural Science Foundation of China(51606107,51576102)the Collaborative Innovation Project of Green Tire and Rubber(0200501436)
文摘Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H2O2) and distilled water(H2O). The functional groups on the surface of CNTs, changes in nanotube structure and morphology were characterized by Fourier transform infrared spectroscopy(FT-IR), Raman Spectroscopy, and transmission electron microscopy(TEM). It shows that hydroxyl(OH·) is successfully introduced. The surface defects of modified CNTs were obviously higher than those of original CNTs, and the degree of agglomeration was greatly reduced. Thermal conductivity of the composites was tested by protection heat flow meter method. Compared with unmodified CNTs/CB filling system, the thermal conductivity of hybrid composites is improved by an average of 5.8% with 1.5 phr(phr is parts per hundred rubber) of hydroxyl CNTs and 40 phr of CB filled. A three-dimensional heat conduction network composed of hydroxyl CNTs and CB, as observed by TEM, contributes to the good properties. Thermal conductivity of the hybrid composites increases as temperature rises. The mechanical properties of hybrid composites are also good with hydroxyl CNTs filled nanocomposites;the tensile strength, 100% and 300% tensile stress are improved by 10.1%, 22.4% and 26.2% respectively.
文摘The pyrolytic process of polycarbosilane (PCS) with active fillers (Ti, TiH 2, TiB 2, Cr, CrSi 2) is investigated. The ceramic yields with active fillers reach over 100% in N 2 atmosphere, and no shrinkage occurs when 12vol% Ti, or 4vol% Cr, or 3vol% CrSi 2 is added into PCS. XRD patterns indicate that metal carbides and nitrides form by reacting with gaseous evolution and N 2.
文摘Polymer electrolyte membranes based on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDFHFP) with and without different types of micro inorganic fillers were prepared by phase-inversion process. Morphologies, porosities and electrochemical properties 'of the as-prepared membranes were investigated by means of scanning electronic microscopy (SEM), PC (propylene carbonate) uptake and alternating current (AC) impedance technique. Compared with other membranes, the membrane with micro SiO2 filler shows a dense morphology so that its PC uptake is the highest, namely, 339 %. The membrane filled with micro TiO2 exhibits good electrochemical performances: the ion conductivity is as high as 1.1 × 10^-3 S/cm at 18 ℃, which can meet the demand of lithium ion batteries. Moreover, its initial charge-discharge efficiency exceeds 89 %. The composite membranes with micro SiO2, TiO2 and Al2O3 are more suitable for the utilization in lithium ion batteries due to better cycle.ability, whereas the battery assembled with the blank membrane containing no inorganic fillers encounters a short circuit after the 5th cycle.
基金Funded by the National Natural Science Foundation of China(Nos.51408287 and 51668038)the Rolls Supported by Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R29)+2 种基金the Distinguished Young Scholars Fund of Gansu Province(1606RJDA318)the Natural Science Foundation of Gansu Province(1506RJZA064)the Excellent Program of Lanzhou Jiaotong University(201606)
文摘The objective of this paper was to develop a comprehensive evaluation method and index to evaluate the performance of sealants and fillers for cracks in asphalt concrete pavements using the method of principal component analysis. The performance experiments including cone penetration, softening point, flow, resilience and tension at low temperature respectively were conducted by reference of ASTM D5329 for eight sealants and fillers often used in China. There by a principal component model was developed and weight of every index was calculated. The experimental results show that there are significantly different performances for sealants and fillers often used in China. Principal component analysis is an objective method that evaluates and selects the performance of sealants and fillers for cracks in asphalt concrete pavements.
文摘The presents preparation and characterization of different types of lignocellulosic fillers(pine wood sawdust/walnut shell flour/black rice husk powder) reinforced polypropylene composites were presented. The effect of MAPP as coupling agent(4 wt%) on the physical and mechanical properties was also investigated. Polypropylene composites were prepared at different rates of filler/matrix(wt%) by using extrusion(for melt blending) and hot compression molding process. Maximum values of tensile and flexural strength were obtained as 26.1 and 43.4 MPa, respectively, whereas the elongation at break value was 4.11% at 10% pine wood sawdust reinforced PP. Tensile and flexural modulus of composites reached the maximum values as 3855 and 3633 MPa with the composite of 30% walnut shell flour reinforced PP. Characterization of composites was carried out by using tensile test, flexural test, FT-IR, and SEM.
文摘The flexural strengths and oxidative resistant properties of the ceramics derived from polycarbosilane and active fillers (Ti, TiH 2, TiB 2, Cr, and CrSi 2) were measured and characterized. The introduction of active fillers enhances slightly the flexural strengths, and further densification is required to obtain higher strengths. The oxidative resistant behaviors of the specimens with active fillers are, by means of weight gain in air, poorer compared with those without active fillers.
基金The work was financially supported by the National Basic Research Program of China(No.2005CB623800).
文摘The surface of calcium carbonate(CaCO_3)particles was modified with stearic acid(SA)and the chemical structures of the product were characterized by FT-IR analysis.The interaction between polydimethylsiloxane(PDMS)and CaCO_3 fillers with different surface character was investigated by means of dynamic rheological and bound rubber tests for uncured compounds and mechanical properties measurements for the corresponding vulcanites.The results of dynamic tests indicate that with the increase of SA mass fraction...
文摘Different types of carbon-silica fillers were prepared via pyrolysis-cum-water vapor of waste green tires tread and impregnation method. Dual phase fillers have been characterized by energy dispersive X-ray (EDX) spectroscopy in a scanning transmission electron microscope (STEM) or STEM-EDX. Phase distribution in hybrid fillers for rubber was investigated. The results achieved show that the conditions of obtaining influence the distribution and the location of the phases in the carbon-silica hybrid fillers as well as their most essential characteristics including specific area, oil absorption number, iodine adsorption number, ash content and others.
文摘Preparation of hydroxyapatite(HA)through natural sources,such as fish scales or synthetic HA produced from the chemical reaction has been widely used as biomedical materials because HA is bioactive,non-toxic and osteoconductive with a crystallographic structure almost similar to that of the bone mineral.In addition,HAwith particle size<10 microns is classified as common inorganic filler used to improve the mechanical properties and biocompatibility of polymer composites.The purpose of this review is to collect information related to HA,and to provide readers with information about synthesis methods,advantages of hydroxyapatite as biomaterial,biomedical applications of polymer/HA composites.
文摘Plain weave woven glass fabric reinforced epoxy (G-E) composite filled with two different types of fillers namely graphite, silicon carbide (each 5 and 10 wt%) was fabricated by hand lay-up method and compressed using hot press. These composites were investigated for their static mechanical properties such as tensile, flexural properties and impact strength as well as mode-I fracture toughness as per ASTM standards. Experimental results on mechanical properties indicate that the strength and the modulus in tensile and flexural mode for G-E composite increase with increasing filler loading. The unfilled G-E composite has the tensile strength of 305 MPa and increased to 404.2 MPa for 10 wt% silicon carbide. However, in three-point bend mode, addition of graphite in G-E showed the highest flexural strength as well as modulus. Mode-I fracture toughness test results indicated that the graphite filler loading improved the toughness of G-E composite. Selected failed samples under tensile, bending and mode-I fracture were examined using scanning electron microscope to identify the fracture features.
文摘Amorphous filler Ti-Zr-Cu-Ni with better performance and higher melting point than the α → β phase transition temperature 882.5°C of TA2, is appropriate for joining TC and TB titanium alloys but not for TA titanium alloys, with which the ductility of the joined base metal TA2 gets down. In this paper, Sn is added into Ti-Zr-Cu-Ni filler to reduce its melting temperature then to satisfy the joining temperature requirement, and the effects of the content of Sn on the microstructure of the alloy and brazing performance are investigated. The results show that, the Ti-Zr-Cu-Ni-Sn brazing foils still possess amorphous structure;the melting point of fillers is reducing with the increase of the Sn content;the joint gap that formed during brazing TA2 and Q235 using Ti-Zr-Cu-Ni-Sn foils is fully filled with continuous compact surface and smooth uniform fillet;the shear strength of the joint is raising with the increase of Sn content in brazing fillers and the strength reaches to 112 MPa when Sn content is 3%;adding more Sn, more brittle intermetallic compounds TiFe and TiFe2 are gathering to form cluster and the shear strength of the joint is reducing;the shear fracture always occurs in the center of the seam.
文摘The aims of this study were to prepare natural hydroxyapatite from fish scales(FsHAp)for potential use as a filler in polymer.The FsHAp was prepared from Tilapia fish scales using thermal method.The FsHAp was milled for 48 h and dried by spray method.The morphology was characterized using field emission scanning electron microscope(FESEM)which showed irregular shape of FsHAp particles with particle size around 7μm.The analysis of FsHAp was carried out using Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD)to confirm chemical structure of FsHAp.
文摘High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The formations of pools or pearls in HA fillers could be observed real time during injection. The plane of injection could be determined accurately, and there were no specimen manipulation artifacts. It was observed that HA gel fillers with differing production technologies showed distinct spread and distribution patterns in the periocular tissues on HRU examination. The authors used HRU to assess deep injections of CHAP-Hyaluronic Acid (CHAP-HA) fillers for midface lift. 10 patients who underwent bilateral midface deep injections using CHAP-HA filler were examined with HRU before and immediately after treatment, and in 2 weeks and one month later. The CHAP-HA appeared as hypoechoic densities within the preperiosteal plane in HRU. CHAP-HA adopted variable morphology within the tissue depending on individual tissue densities and the compliance of the tissues in the plane of injection. CHAP-HA was unidentifiable with surrounding tissue after one month in 13 of the 20 injection sites. HRU allows in vivo study of CHAP-HA injection behavior and could be a tool for further studies of HA-tissue reactions.
文摘This study aims to determine the optimal quantity of fillers to add to hydraulic concrete and to assess the influence of these fillers on its rheological characteristics and mechanical properties. The characterization of the aggregates shows that they meet the specifications for the formulation of hydraulic concrete according to the Dreux-Gorisse method. Normalizing the formula to the cubic meter enables to define the standard concrete. The cement content is 350 kg/m<sup>3</sup>. The mineral materials added to the concrete to increase its characteristics and properties are limestone, basalt, and sandstone fillers with a weight percent of 4%, 5%, and 3% respectively. Changes in concrete properties with the addition of fillers were determined through geotechnical tests. The results obtained show a decrease in the workability measured by slump test which returned 7.8 cm for the standard concrete sample, 7.2 cm with 5% of basalt, 7.3 cm with 4% of limestone, and 6.1 cm with 3% of sandstone. Regarding the bleeding, the results show that it decreases leading to a substantial improvement in stabilization reaching 26% with 5% of basalt fillers, 29% with 4% of limestone fillers, and 31% with 3% of sandstone fillers. The compressive strengths noted R<sub>c28</sub> at 28 days increases compared to that of the standard concrete, which is 31.5 MPa. They increase to 34.3 MPa with 5% of basalt fillers being 8.9%, 36.2 MPa with 4% of limestone fillers being 14.9%, and 36.8 MPa with 3% of sandstone fillers being 16.8%. Finally, the addition of fillers increases the degree of compaction values to 83.62% with 5% of basalt fillers, 84.2% with 4% of limestone fillers, and 84.34% with 3% of sandstone fillers.
文摘Ti-Zr-Cu-Ni amorphous filler with good performance is suitable for joining TC and TB titanium alloy, but its melting temperature is higher than 882.5°C, the α→β phase transition temperature of TA2, which makes the ductility of TA2 fall and the microstructure of the joint coarse. In this paper, Ti-Zr-Cu-Ni amorphous filler was redesigned and optimized by using orthogonal experiment to obtain three easy-to-use Zr-Ti-Ni-Cu amorphous fillers with low melting points and good plasticity. The fast cooling equipment was used to fabricate the brazing filler foils to implement the braze welding of TA2 and Q235 with high frequency inductance. The results indicate that all the brazing foils are amorphous structure with lower melting temperature, for example, Zr52Ti22Ni18Cu8 filler’s is 538°C. The technical parameters in brazing welding are: welding temperature T = 800°C;heating electric current I =25 A;heating time t = 15 s and holding time t = 15 s, in the case of these conditions, the jointing head shear strength of TA2/Zr52Ti24Ni13Cu11/Q235 is 139 MPa. Fracture is mainly located in the brazing seam. The white brittle intermetallic TiFe, TiFe2 and enhancement TiC spread in the center zone of brazing seam.
文摘Background: Semi-permanent fillers are among the most favorable fillers on the market. Through their unique mode of action and its associated lasting aesthetic effect, they take an exceptional position. Objective: To compare the two semi-permanent fillers Poly-L-Lactic Acid (PLLA) and calcium hydroxylapatite (CaHA) in reference to the aesthetic result, patient satisfaction and side effects. Methods: Studies on side effects, patient satisfaction and aesthetic results after augmentation with semi-permanent fillers were analyzed. Results: Semi-permanent fillers seem excellently suited for the augmentation of very deep wrinkles particularly in the lower half of the face. In general, high patient satisfaction can be determined with both fillers. Here, the effect from the polylactic acid can be verified for up to two years while no effect could be verified already after one year in a majority of the patients augmented with CaHA. Short-term side effects such as bleedings or erythema in the region of the augmented area have been observed in both fillers during augmentation. The incidence of nodules and granulomas seems significantly higher in augmentations with PLLA compared to CaHA. Rare side effects such as an embolization of a blood vessel caused by the implant have been described for both fillers in case reports. Conclusion: Semi-permanent fillers are superbly suited for wrinkle augmentation. Which filler is the preferred one in what case depends strongly on the individual needs of the patient and the therapist’s experience.