Filler Mass Fraction Research Articles

Novel Resin-Based Antibacterial Root Surface Coating Material to Combat Dental Caries.

Root caries caused by cariogenic bacteria are a burden on a large number of individuals worldwide, especially the elderly. Applying a protective coating to exposed root surfaces has the potential to inhibit the development of caries, thus preserving natural teeth. This study aimed to develop a novel antibacterial coating to combat root caries and evaluate its effectiveness using the antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM). DMAHDM was synthesized and incorporated into a resin consisting of 55.8% urethane dimethacrylate (UDMA) and 44.2% TEG-DVBE (UV) at a 10% mass fraction of glass filler. Multiple concentrations of DMAHDM were tested for their impact on the resin's mechanical and physical properties. S. mutans biofilms grown on resin disks were analyzed for antibacterial efficacy. Cytotoxicity was assessed against human gingival fibroblasts (HGFs). The results showed an 8-log reduction in colony-forming units (CFUs) against S. mutans biofilm (mean ± sd; n = 6) (p < 0.05) when 5% DMAHDM was incorporated into the UV resin. There was a 90% reduction in metabolic activity and lactic acid production. A low level of cytotoxicity against HGF was observed without compromising the physical and mechanical properties of the resin. This coating material demonstrated promising physical properties, potent antibacterial effects, and low toxicity, suggesting its potential to protect exposed roots from caries in various dental procedures and among elderly individuals with gingival recession.

Enhanced thermal conductivity of electrically insulating polydimethylsiloxane composites with boron nitride nanosheet and aluminum oxide for thermal management on flexible electronics

AbstractWith the trend of integration and miniaturization of stretchable electronics, thermal management has been a crucial issue. Developing novel materials with high thermal conductivity (TC) and flexibility is urgent. Herein, we report a stretchable polydimethylsiloxane (PDMS)/boron nitride nanosheet (BNNS)@spherical aluminum oxide (Al2O3) composite with high TC and electrical insulation prepared by a two‐step strategy of sucrose‐template and hot‐pressing. An effective foam‐pressing route benefits the composites to form a three‐dimensional thermally conductive networks, improving the in‐plane TC value of the resultant composite to 4.03 W/(mK) at the filler mass fraction of 35.7 wt% and enhancing to 4.66 W/(mK) under 40% stretching ratio. Meanwhile, the composites can be restored to their former state and retain thermally conductive stability with repeated bending and twisting tests. Moreover, the composites were applied in LED with stretching, exhibiting good heat dissipation performance. These results demonstrate this PDMS composite can be potentially utilized as a high‐performance material to solve thermal management problems in flexible electronics.Highlights The heat conduction network is prepared by sucrose‐template and hot‐pressing. BNNS@P‐Al2O3 fillers are self‐assembled via the electrostatic interaction. The composites exhibit good thermal conduction and superior flexibility. The thermal conductivity of the composite increases after stretching. The composites can retain thermal conductive stability after deformation.

In-situ reduction of AgNPs on MXene surfaces for synthesis of efficient thermally conductive composites with powerful electromagnetic shielding capabilities

Thermally conductive materials are crucial for stable operation of integrated circuits, and there is high interest in improving the thermal conductivity of MXene. This study develops a facile method to enhance the chelating and reducing abilities of MXene towards metal ions by coating a thin layer of polydopamine onto the MXene surface, followed by decoration of silver nanoparticles on the nanosheet surface through in-situ reduction. Naturally abundant nanocellulose fibers were used as the matrix, and continuous thermal pathways were constructed between the fibers by vacuum filtration of the prepared nanofillers. The essential role of AgNPs in providing efficient thermal conductive networks was analyzed using the finite element analysis software. The prepared composite films exhibited an in-plane thermal conductivity up to 7.31 W/m K and demonstrated superior temperature control in heat dissipation tests. At a filler mass fraction of 30 wt%, the average electromagnetic shielding effectiveness of the film with a thickness of 0.17 mm was measured to be 25.8 dB in the X-band, which exceeds the target value for commercial applications. The outstanding performance of the composite paper has demonstrated the great potential of silver-decorated MXene for widespread application in fields such as electronic devices, aerospace, and aviation.

The Analysis Of Micromechanic On Creating Of Gypsum Board Strengthened By Bintaro Fruit Fiber (Cerbera Manghas) With 3d Orientation

This research succeeded in modifying the manufacture of gypsum board with the addition of natural fiber, namely bintaro fruit with the 3D orientation arrangement method. The raw materials for this research are gypsum flour and Bintaro fruit fiber as a matrix and filler. Bintaro fruit fiber previously carried out an alkalization process where the fiber was soaked in a solution of NaOH and distilled water for 24 hours. The manufacture of composites using the ratio of the matrix mass fraction and the filler mass fraction is as follows 100: 0, 99: 1, 98: 2 and 97: 3. The characterizations carried out include density test, moisture content test, flexural strength test and micromechanical analysis. Gypsum board composite based on micromechanical calculations resulted in the highest density value in the control sample, in the best density value was at the filler fraction of 3%, the best moisture content value in the control sample, the flexural strength test value the best of the control sample, but the filler fraction is 3% of the sample with the best fracture resistance. 3D orientation in theory and practice has fulfilled the principle that it is able to increase the physical and mechanical value of gypsum board.

Characteristics of Termite Anti Particle Board From Bintaro Fruit Fiber With Bintaro Fruit Seed Extract Coating Using Spray Coating Method

Termites are pests that damage wooden furniture. Termite attacks on wooden furniture are getting higher and wider so that the value of losses due to termite attacks on furniture is increasing from year to year. This research has succeeded in making particle boards from bintaro fruit fibers as fillers and urea formaldehyde resin (UF) as a matrix with a composition of filler mass fractions: the matrix of the particle board to be made is 30:70. The particle board that has been made is then coated using bintaro seed extract and UF resin using the spray coating method. The extract mass fractions of bintaro seeds and UF resins in this study were sample 1 (90:10), sample 2 (80:20), sample 3 (70:30), sample 4 (60:40) and sample 5 (50:50). The physical characterization of particleboard includes density, water absorption and moisture content. The mechanical characterization of particle boards is the bending strength and characterization of particle boards to resistance to termite attacks. The results of this study show that particle boards that have optimum values are sample particle boards 1 with a density value of 0.864 gr / cm³, water absorption of 4.28% which has met SNI 03-2105-2006 and the results of testing the resistance to termites 3.45% have met SNI 01-7207-2006. Because in the manufacture of particle boards are influenced by the structure and physical shape of the raw materials used.

Molecular dynamics simulation of thermal conductivity of diamond/epoxy resin composites

Improving the thermal conductivity (TC) of epoxy resin thermal interface material is of great significance in tackling the heat dissipation problem of high heat flux in microelectronic chips such as 5G. Using non-equilibrium molecular dynamics (MD) method, the effects of two different filling styles of nano-diamond fillers on the TC of EP based composites are investigated. The results show that the TC of the composite increases with the diamond size when single-particle filling is used, and that a larger diamond size leads to a more significant reduction of the free volume fraction and thus an improvement of the TC. In the multi-particle packing, the composite TC first increases and then decreases with increasing particle number. Increasing the number of particles reduces the free volume fraction, but also results in a larger specific surface area and interfacial thermal resistance, which has a more significant weakening effect on the TC. Moreover, within the same mass fraction of nano-diamond filler, increasing the filler size has a more significant TC improvement on the composite than increasing the number of particles. This study is instructive for the design and preparation of high thermal conductivity nanodiamond/epoxy resin composites.

Identification of the Utilization of Jember Coffee Skin Biocomposite (Coffea Canephora) as a Sound Absorber Using the Tube Method

The development of technology and information is in line with the era of society 5.0 which occurs in various fields, especially in terms of infrastructure which of course will lead to high mobility. One of the negative impacts that arise is noise. For that we need a material that can be used as an acoustic material that functions to absorb sound. Coffee waste is one of the agricultural wastes that can be used as an acoustic material. The purpose of this study was to determine the effect of the sound damping coefficient on sound intensity and the mixture of filler and matrix mass fractions that can be used to muffle sound. The tube method with the Sound Level meter feature from Smartphone will be used to determine the value of the sound attenuation coefficient. In this study, the sound intensity used was 60-100 dB, with a mass ratio of filler and matrix used was 80%:20%, 70%:30%, 60%:40%, 50%:50% and the thickness used is 10mm. The results of the study show that an increase in intensity for each sample will show a decreasing coefficient for each sample. This is due to the higher the intensity of the sound, the higher the sound energy will also be greater so that it is more difficult for the sample to absorb

Passive Filler-Loaded Silicon Oxycarbide Coating on Nickle Alloy with High Thermal Shocking Behavior and Oxidation Resistance.

Polymer-derived ceramic (PDC) coatings of considerable thickness can offer promising protection for metallic and superalloy substrates against oxidation and corrosion, yet the preparation remains challenging. Here, a SiOC/Al2O3/YSZ coating was prepared on a nickel alloy with a spraying method using Al2O3 and yttria-stabilized zirconia (YSZ) as passive fillers. The thickness can reach up to 97 μm with the optimal mass fraction and particle sizes of the passive fillers. A small or isolated SiOC phase is formed in the coating, which can effectively alleviate the shrinkage and cracking during the pyrolysis. The SiOC/Al2O3/YSZ coating exhibits low thermal conductivity and high bonding strength with the substrate. Moreover, the coating shows good thermal shock resistance between 800 °C-room temperature cycles and oxidation resistance at 1000 °C for 36 h. This work provides an effective guide for the design of thick PDC coatings to further promote their application in the thermal protective field.

Flexible and Robust Ti3C2Tx/(ANF@FeNi) Composite Films with Outstanding Electromagnetic Interference Shielding and Electrothermal Conversion Performances

Flexible and robust multifunctional electromagnetic interference (EMI) shielding materials are playing an increasingly important role in areas of aerospace, electronic communication, artificial intelligence, and wearable electronic devices. Herein, the magnetic and conductive Ti3C2T x /(ANF@FeNi) EMI shielding composite films are fabricated via in situ growth and vacuum‐assisted filtration methods. The introduction of magnetic FeNi nanoparticles can effectively enhance the electromagnetic recombination losses, leading to improved EMI shielding effectiveness (EMI SE) of the composite films. The obtained Ti3C2T x /(ANF@FeNi) composite films show excellent EMI shielding and electrothermal conversion performances. When the mass fraction of Ti3C2T x and FeNi fillers is 60 wt% and their mass ratio is 4:1, the EMI SE of the composite films (50 μm) reaches 60.7 dB in the X‐band (8.2–12.4 GHz). When a low voltage of 3 V is applied, the surface heating temperature of the composite films quickly reaches 111.2 °C. Moreover, the composite films possess satisfied long‐term heating stability under the constant applied voltage. In addition, the composite films exhibit excellent thermal conductivity and mechanical properties. The thermal conductivity (λ) and thermal diffusivity (α) reach 4.72 W m−1 K−1 and 4.36 mm2 s−1, respectively, and the tensile strength and tensile modulus reach 113.4 MPa and 3.1 GPa, respectively.

Enhanced Aramid/Al2O3 interfacial properties by PDDA modification for the preparation of composite insulating paper

To further improve the electrical insulation properties of meta-aramid paper, polydimethyldiallyl ammonium chloride (PDDA) was used for the modification of nano-Al2O3 in this work. The modified products were characterized by means of transmission electron microscopy, Fourier transform infrared spectrometer and liquid Zeta potential. The original and PDDA-modified nano-Al2O3 was doped into the aramid fiber composite, and the effects of PDDA and filler mass fraction on several properties such as electrical conductivity, breakdown strength and surface charge dissipation rate of insulating paper were studied. Finally, the interfacial properties of the composites were investigated using molecular dynamics. The results showed that PDDA was successfully coated on the surface of nano-Al2O3, and its surface potential was changed from negative to positive, which could improve the interface characteristics between filler and matrix and enhance the dielectric strength of aramid paper. Besides, saturation effect of PDDA modification was observed, and when the amount of PDDA was 10% and the content of modified nano-Al2O3 was 3%, the breakdown strength of aramid paper was increased by 20%, and the volume conductivity was decreased by 68%. The simulation result revealed that PDDA could improve the insulation performance of aramid paper by reducing the interfacial binding energy between aramid and filler.

Dielectric properties of polyarylene ether nitrile composites based on modified boron nitride

Polyarylene ether nitrile (PEN) is a new type of super engineering polymer with excellent high-temperature resistance, radiation resistance, good electrical insulation, and mechanical properties. In this work, boron nitride (BN) and copper phthalocyanine (CuPc) hybrids were integrated as fillers, which were further dispersed into PEN matrix by solution casting method to obtain a series of PEN composite films. The successful preparation of hybrid fillers was proved by means of X-ray photoelectron spectroscopy and scanning electron microscopy. The test results of the dielectric properties of the composite films show that the CuPc-BN/PEN films exhibit good dielectric properties. When the mass fraction of filler reaches 10 wt%, the dielectric constant of the PEN composite film increases by 17%. This study shows that the composites composed of modified BN and PEN has excellent dielectric properties and has great application potential in heat-resistance thin-film capacitors.

Optimising the electroluminescence performance of ZnS: Cu/epoxy composites via exploring the relationship between electroluminescence intensity and filler intrinsic attributes

Electroluminescent composites have considerable potential for applications in photoelectric display, electric field measurement and other fields due to their advantages of simple preparation and uniform luminescence. However, high voltage required by the operation of electroluminescent composites hinders their applications in the electric domain, and research on the relationship between electroluminescence principle of composites and filler intrinsic attributes is insufficient. In this paper, the effects of electric field strength, filler mass fraction and voltage frequency on the electroluminescence intensity of ZnS: Cu/epoxy composites are studied, which are majorly used as the luminescent layer of electroluminescent devices. To enhance the electroluminescence intensity of composites, high-temperature sintered BaTiO3 and zinc oxide whiskers (ZnOw) particles are introduced in the base matrix. The finite element method is applied to verify that the matrix of high dielectric constant is in favour of improving the electroluminescence intensity of composites. The band structure of the ZnS: Cu particle is calculated based on the density functional theory + U method to analyse the intrinsic relationship between electroluminescence and particle electronic structure. This paper provides a basis for the research of high electroluminescence intensity devices and will be conducive to better understanding on the relationship between electroluminescence principle and filler intrinsic attributes.

Solvent-free green synthesis of nonflammable and self-healing polymer film electrolytes for lithium metal batteries

Fire-resistant and self-healing flexible electrolytes are a promising alternative to address thermal runaway in lithium batteries. However, self-healing electrolytes for lithium batteries are not widely used due to their low ionic conductivity, limited self-healing ability, and potential combustion risk. Ionic liquid-based polymer electrolytes are a simple and effective approach to obtaining polymer solid electrolytes with high ionic conductivity, fast self-healing and flame retardant properties. In this work, methyl methacrylate (MMA) and 1-Allyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide (AMIMTFSI) are used as the membrane-forming backbone and also possess ion transport channels. 1-ethyl-3 methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (EMIMTFSI) is added to the membrane to further enhance the ionic conductivity. Due to the existence of ionic liquid units and free ionic liquids in the prepared electrolytes, the fast interaction of ionic bonds confers a faster self-healing ability to the films, and the flame retardancy of the ionic liquids is fully maintained after polymerization. The prepared electrolytes show good flame retardance properties, excellent mechanical properties (tensile rate is ∼ 400%), high thermal decomposition temperature (>260 °C), and can effectively enhance the reliability of lithium metal batteries. When ionic liquids filler mass fraction is 40%, the polymer electrolytes have an ionic conductivity of 1.9 × 10-4 S cm−1, a decomposition voltage of 4.6 V (vs. Li/Li+), and can achieve an initial discharge capacity of 134.9 mAh g−1 with a capacity retention of 96.4% after 90 cycles at 0.1C for LiFePO4/Li half-cell at 25 °C.

Conductive properties of flexible polymer composites with different carbon-based fillers

This paper is devoted to the comparative study of conductive properties of three types of flexible polymer composites consisting of styrene-butadiene rubber (SBR) as a matrix and graphite, graphene or single-walled carbon nanotubes as fillers. The dependences of the resistivity on the mass fraction of different fillers are measured and analyzed within the framework of the statistical percolation theory. The percolation parameters (the values of the percolation threshold and the critical exponent) are calculated for all studied composites. Their variation depending on the filler type is discussed, taking into account a geometric shape of filler particles and the nature of the conduction process in composites in the percolation range. The sensitivity of the resistivity of synthesized composites to axial deformation at different mass fraction of fillers is also investigated. Using graphite or graphene fillers is observed to result in a higher sensitivity compared to the carbon nanotubes filler. The highest value of the gauge factor is observed when using 23 mass.% graphene filler that indicates graphene/SBR composites to be most promising for creating strain sensors.

Study on water absorption and mechanical properties of CNF–Ti reinforced epoxy resin composites

ABSTRACT The effects of carbon nanofibres (CNFs), titanium nanoparticles (Ti) and CNF–Ti fillers on the water absorption and mechanical properties of the composites were studied. The results showed that with the increase in filler mass fraction, the water absorption and mechanical properties of epoxy resin composites showed a trend of first increasing and then decreasing. When 6% CNF–Ti filler was added, the water absorption and diffusion coefficients of the composites were reduced to 2.32% and 1.04 ± 0.05 × 10−6 m2/s, and their tensile and impact strengths were improved by 200% and 124.55%, respectively, compared with the pure resin. However, when the filler was added in excess, agglomerates were generated inside the composite, which can affect the performance of the composite to a great extent. The above experimental results were verified by morphology observations via scanning electron microscopy.

Influence of content and degree of substitution of carboxymethylated cellulose nanofibrils on the gelation properties of cull cow meat myofibrillar proteins

Cull cow meat myofibrillar protein (CCMP) filled with carboxymethylated cellulose nanofibrils (cCNF) was initially characterized to study the effect of cCNF on the gelation properties of CCMP. Before heating, with the increased degree of substitution (DS) of cCNF, the ζ-potential and hydrophobicity of CCMP-cCNF solution increased at the same filler mass fractions (ϕm). During heating, the process of gelation was shortened after adding cCNF, especially samples filled with cCNF of high DS. After heating, the cCNF with lower DS led to the lower liquid loss of gels, and the effect was amplified with increased ϕm of cCNF. Similarly, the network structure of CCMP-cCNF with low DS was more compact and the ability to anti-deform was stronger according to scanning electron microscopy and texture analysis. Also, an Interpenetrating Polymer Network was formed. Overall, ϕm of cCNF had a positive effect on the gelation properties of CCMP by water channel blocking and physical entanglement, while cCNF with higher DS weakened this effect due to electrostatic repulsion. This study may provide a theoretical foundation about the development of restructured meat products.

Effect of Bismuth Ferrite Nanometer Filler Element Doping on the Surface Insulation Properties of Epoxy Resin Composites.

In the direct current electric field, the surface of epoxy resin (EP) insulating material is prone to charge accumulation, which leads to electric field distortion and damages the overall insulation of the equipment. Nano-doping is an effective method to improve the surface insulation strength and DC flashover voltage of epoxy resin composites. In this study, pure bismuth ferrite nanoparticles (BFO), as well as BFO nanofillers, which were doped by La element, Cr element as well as co-doped by La + Cr element, were prepared by the sol-gel method. Epoxy composites with various filler concentrations were prepared by blending nano-fillers with epoxy resin. The morphology and crystal structure of the filler were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests. The effects of different filler types and filler mass fraction on the surface flashover voltage, charge dissipation rate, and trap characteristics of epoxy resin composites were studied. The results showed that element doping with bismuth ferrite nanofillers could further increase the flash voltage of the composites. The flashover voltage of La + Cr elements co-doped composites with the filler mass fraction of 4 wt% was 45.2% higher than that of pure epoxy resin. Through data comparison, it is found that the surface charge dissipation rate is not the only determinant of the flashover voltage. Appropriately reducing the surface charge dissipation rate of epoxy resin composites can increase the flashover voltage. Finally, combining with the distribution characteristics of the traps on the surface of the materials to explain the mechanism, it is found that the doping of La element and Cr element can increase the energy level depth and density of the deep traps of the composite materials, which can effectively improve the flashover voltage along the surface of the epoxy resin.

Stable Interfaces in a Sodium Metal-Free, Solid-State Sodium-Ion Battery with Gradient Composite Electrolyte

Composite electrolytes (CE) combining a ceramic filler and a polymer matrix is an effective way to enhance battery safety. But the increased ceramic filler mass fraction decreases the flexibility, which increases the interfacial resistance. To alleviate interfacial resistance further, a gradient composite electrolyte (GCE) using a Sc, Ge-doped Na3Zr2Si2PO12 (NZSP) as the ceramic filler and poly(ethylene oxide) (PEO) as the polymer matrix is proposed. The outer layer contains a low concentration of ceramic filler to improve interfacial contact, and the central layer contains a high concentration of ceramic filler to inhibit dendrite penetration. This GCE possesses an enhanced conductivity (4.0 × 10-5 S cm-1 at 30 °C) and a reduced interfacial resistance. Furthermore, the safety was boosted using Sn4P3@CNT/C as the high-capacity anode active material and Na3V2(PO4)3 (NVP) as the cathode active material. This ultrasafe sodium metal-free, solid-state sodium-ion battery (SSSIB) displays an impressive cycling performance.

Influence of active nanofiller ZIF-8 metal-organic framework (MOF) by microemulsion method on anticorrosion of epoxy coatings

In this study, uniform sized ZIF-8 was synthesized by microemulsion method, and a series of ZIF-8 modified epoxy coatings with different mass fractions were successfully prepared. EIS analysis revealed the improved anti-corrosion performance of the modified epoxy coating with increasing mass fraction of ZIF-8 fillers, and this was confirmed by the results of the salt spray and adhesion tests. In addition, the tensile strength and friction properties of the epoxy coating have also been greatly improved. These phenomena were explained by the chemical cross-linking between ZIF-8 fillers and epoxy. The chemical cross-linking increased both the cross-linking density and the barrier performance of the epoxy coating, consequently improving its anti-corrosion and mechanical properties.

Improving the local thermal conductivity of flexible films by microchannels filled with graphene

Low thermal conductivity is an outstanding problem that hinders the application of polymer substrates in flexible devices. Incorporating high thermal conductivity fillers into polymer to enhance its thermal conductivity usually requires a large mass fraction of fillers at the expense of the flexibility and the insulation capabilities of polymer substrates. The non-uniform heat distribution in flexible devices allows for improving the local thermal conductivity of the core areas via microchannels, a strategy which is an effective method in thermal engineering and can be well designed to adapt to large deformation of flexible devices. Here, we report the fabrication of microchannels in polyimide (PI) composite film by oxygen plasma etching and subsequent filling the microchannels with graphene. Utilizing the time-domain thermoreflectance method and the finite element method, we confirmed that the local thermal conductivity of graphene-filled region is about 10 times larger than that of the unfilled region, which is comparable to that of the PI composite filled heavily with traditional high thermal conductive fillers. In addition, it was also found that stretching the film did not lower the thermal conductivity of the same region.