Electrophoretic mobilities of dissolved polyelectrolyte charging agent and suspended non-colloidal titanium during electrophoretic deposition

Coarse (<= 20 microns) titanium particles were deposited on low-carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly(diallyldimethylammonium chloride) (PDADMAC) as polymeric charging agent. Preliminary data on the electrophoretic mobilities and electrical conductivities on the suspensions of these soft particles as well as the solutions themselves as a function of PDADMAC level were used as the basis for the investigation of the EPD parameters in terms of the deposition yield as a function of five experimental parameters: (a) PDADMAC addition level, (b) solids loading, (c) deposition time, (d) applied voltage, and (e) electrode separation. These data were supported by particle sizing by laser diffraction and deposit surface morphology by scanning electron microscopy (SEM). The preceding data demonstrated that Ti particles of 1-20 microns size, electrosterically modified by the PDADMAC charging agent, acted effectively as colloidal particles during EPD. Owing to the non-colloidal nature of the particles and the stabilization of the Ti particles by electrosteric forces, the relevance of the zeta potential is questionable, so the more fundamental parameter of electrophoretic mobility was used. A key finding from the present work is the importance of assessing the electrophoretic mobilities of both the suspensions and solutions since the latter, which normally is overlooked, plays a critical role in the ability to interpret the results meaningfully. Further, algebraic uncoupling of these data plus determination of the deposit yield as a function of charging agent addition allow discrimination between the three main mechanistic stages of the electrokinetics of the process, which are: (1) surface saturation; (2) compression of the diffuse layer, growth of polymer-rich layer, and/or competition between the mobility of Ti and PDADMAC; and (3) little or no decrease in electrophoretic mobility of Ti, establishment of polymer-rich layer, and/or dominance of the mobility of the PDADMAC over that of Ti

Substrate-free thick-film lead zirconate titanate (pzt) performance measurement using Berlincourt method

Lead Zirconate Titanate or PZT is a high performance piezoelectric material which is able to generate charges when a proportional amount of stress is applied on the material. It has the potential to be used to fabricate micro-power generator for powering low power electronic devices, on top of already existence sensors and actuators. One of the indicators for comparing the performance of the smart materials is the piezoelectric charge coefficient, d33. In this paper, the actual d33 of PZT fabricated in the form of substrate-free thick-films were measured using Berlincourt Method whereby a standard dynamic force is applied to the materials and the resultant value of charges is recorded and compared over a period of time after the thick-films were polarized. The d33 values are compared between substrate-based and substrate-free specimens show a difference of about 45 % as a result of clamping effect contributed by d31. The experiment results also show that the thick-film PZT processed at 950 °C and polarized at 220 V with a thickness of about 120 μm has a piezoelectric charge coefficient of 82 pC/N

Effect Of Cationic Charging Agent On The Bonding Strength Of Coarse Titanium Particles Deposited By Electrophoretic Deposition

Electrophoretic deposition (EPD) is a potential coating technique for surface hardening of steel when combined with a subsequent rapid sintering process. This process requires synergy between suspension particles and charging agent, particularly when the particles involved are noncolloidal in nature. The present work will investigate the effect of three commercially-available cationic charging agents; aluminium (III) chloride (AlCl3), polyethyleneimine (PEI) and poly(diallyldimethylammonium chloride) (PDADMAC) on the EPD of coarse Ti particles onto steel. The obtained Ti coatings were characterized by their surface microstructure, deposit yield, electrophoretic mobility and electrical conductivity. The key finding of the present study is the bonding strength of charging agent-adsorbed coarse Ti particles deposits predominantly controlled their deposit yield. Electrophoretic mobility of the Ti particles only played a lesser role in the deposit yield because of strong hindrance of gravity on the moving coarse particles. Charging agent, which gave the strongest to the weakest bonding strength is as follow: AlCl3, PDADMAC (Mw = 100,000 -200,000 amu), PDADMAC (Mw = 400,000 -500,000 amu), PEI

Effect of Charging Agents on Electrophoretic Deposition of Coarse Titanium Particles

The effects of aluminium (III) chloride (AlCl3), polyethyleneimine (PEI), and poly(diallyldimethylammonium chloride) (PDADMAC)] as charging agents on the electrophoretic deposition (EPD) of coarse (≤20 μm) titanium (Ti) particles onto low-carbon steel cathodic substrates were assessed through microstructural evaluation, deposit yield, electrophoretic mobility measurements, and electrolytic corrosion. Apart from the capacity to achieve high bonding strength and yield, PDADMAC resulted in lower electrolytic corrosion of the anode and introduced less anionic contamination than AlCl3 or PEI. The quality of the EPD deposit in terms of its bonding strength and deposit yield depended on the length scale of the charging agents used in addition to the intrinsic nature of the charging agent (ionic functional groups and sites). Minimisation of the PDADMAC addition level and PDADMAC of lower molecular weight are advantageous for surface hardening purposes owing to lower the carbon content introduced into the deposit yield

Electrophoretic Mobilities Of Dissolved Polyelectrolyte Charging Agent And Suspended Non-Colloidal Titanium During Electrophoretic Deposition

Coarse (<= 20 microns) titanium particles were deposited on low-carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly (diallyldimethylammonium chloride) (PDADMAC) as polymeric charging agent. Preliminary data on the electrophoretic mobilities and electrical conductivities on the suspensions of these soft particles as well as the solutions themselves as a function of PDADMAC level were used as the basis for the investigation of the EPD parameters in terms of the deposition yield as a function of five experimental parameters: (a) PDADMAC addition level, (b) solids loading, (c) deposition time, (d) applied voltage, and (e) electrode separation. These data were supported by particle sizing by laser diffraction and deposit surface morphology by scanning electron microscopy (SEM). The preceding data demonstrated that Ti particles of 1-20 microns size, electrosterically modified by the PDADMAC charging agent, acted effectively as colloidal particles during EPD. Owing to the non-colloidal nature of the particles and the stabilization of the Ti particles by electrosteric forces, the relevance of the zeta potential is questionable, so the more fundamental parameter of electrophoretic mobility was used. A key finding from the present work is the importance of assessing the electrophoretic mobilities of both the suspensions and solutions since the latter, which normally is overlooked, plays a critical role in the ability to interpret the results meaningfully. Further, algebraic uncoupling of these data plus determination of the deposit yield as a function of charging agent addition allow discrimination between the three main mechanistic stages of the electrokinetics of the process, which are: (1) surface saturation; (2) compression of the diffuse layer, growth of polymer-rich layer, and/or competition between the mobility of Ti and PDADMAC; and (3) little or no decrease in electrophoretic mobility of Ti, establishment of polymer-rich layer, and/or dominance of the mobility of the PDADMAC over that of Ti

Superconducting properties of bulk Bi(Pb)-Sr-Ca-Cu-O with nanopowder CoFe2O4 addition

The efforts to improve the superconducting properties of high temperature superconductor in the aspect of supercurrent transport ability have been made by introducing artificial pinning sites. Several techniques include heavy ion bombardment, proton irradiation, neutron irradiation and atomic substitutions had been used and found its own difficulties when applied in large-scale production. One of solution to overcome these problems is the addition of nanometer size particles as pinning centres to the superconductor which had been found effective to improve the pinning strength of superconductor In this paper, the superconducting properties of bulk Bi(Pb)-Sr-Ca-Cu-O with nano-powder CoFe2O4 addition will be investigated by Tc and Jc measurements. Data obtained from XRD and SEM will also be presented

DSC assessment on curing degree of micron-scaled adhesive layer in lamination-pressed flexible printed circuit panels

Continuous monitoring and optimisation of the lamination process are critical in negating flexible printed circuit (FPC) delamination risk during operation. The main QC inspection criterion of the lamination adhesive’s curing degree is adhesive thickness. However, this method is prone to measurement error due to poor microscopy image definition and the inspector’s measurement parallax error. The feasibility of using thermal characterisation to measure the difference in curing degrees of micron-scaled adhesive layer of laminated FPC was investigated. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used according to IPC standards. Polyimide-epoxy adhesive coverlays were laminated onto both sides of FPC at 120 kgf/cm2 pressure and 180 °C temperature for 120 s. Then, the coverlays were subjected to oven curing at 150 °C for 60 min. The DSC detected a small difference in the curing degree of adhesive layers in the two cured FPC laminated in different laminating-press openings (T1 and T2). T2 had a glass transition temperature (Tg) of 106.5 °C, which was higher than that for T1 (105 °C), thereby suggesting that the former had a higher curing degree than the latter. This result was consistent with the adhesive thickness measurement result of the DSC samples. The adhesive thickness of T2 was smaller (30.97 µm) than that of the T1 (31.76 µm). T2 had a higher curing degree than T1 because of the larger shrinkage percentage. In comparison with DSC, TGA was unable to detect the curing degree difference between the samples because of the undetected weight loss resulting from the adhesive curing

Electrophoretic deposition of hexagonal boron nitride particles from low conductivity suspension

Given that hexagonal boron nitride (hBN) particles are extremely stable in colloidal suspensions due to their low density, they are difficult to deposit via electrophoretic deposition (EPD). Poly (diallyldimethylammonium chloride) (PDDA) is widely used as a polyelectrolyte for ceramic particles because of its strong electrophoretic response. Nevertheless, studies on PDDA as a functionalising agent of hBN particles for EPD remain elusive. Here, hBN particles were functionalised with different amounts of PDDA to investigate effects on suspension stability and EPD yield. Deionised (DI)-water-based hBN particle suspensions with PDDA contents that varied from 0.3 wt% and 0.6 wt% (of hBN basis) were prepared using washed as-received hBN particles. Then, washed and nonwashed PDDA-functionalised hBN particle groups were prepared by subjecting only the former to water washing. Washing, which involved the repeated particle dispersion in DI water and vacuum filtration, successfully reduced the conductivity of the aqueous hBN suspension to 2 µS/cm, which was significantly lower than the conductivities of ∼180 and ∼25 µS/cm shown by the as-received particle suspension and PDDA-functionalised particles before washing. This result indicated that washing eliminated the interference of free ions on the suspension stability of hBN particles and EPD yield. In contrast to that of the nonwashed group, the suspension stability of the washed group decreased as the PDDA content was increased. Nevertheless, at 0.3 wt% and 0.6 wt% PDDA, the EPD yields of the washed group were 183% to 31% higher than those of the nonwashed group. This study provided new insight into the EPD of hBN particles using low-cost aqueous suspensions with sustainable ultralow ion conductivity

Design and Characterization of Piezoelectric P(VDF-TrFE) Thick Film on Flexible Substrate for Energy Harvesting

This paper discusses on the design and fabrication steps of piezopolymer using poly(vinylidene fluoride) trifluoroethylene, P(VDF-TrFE) thick film on the flexible substrate using screen-printed method. Polyethylene terephthalate, PET film was used as a substrate to hold P(VDFTrFE) thick film in between sandwiched layers of electrodepiezopolymer-electrode. The P(VDF-TrFE) thick film is then annealed at 100 °C and polarized at 100 V for the film and inspected under EDS, FESEM and XRD for the characterization process. The flexible piezoelectric P(VDFTrFE) thick film is able to generate maximum output peak power of 4.36 µW at an external load of 1kΩ with generated maximum peak-to-peak voltage about 3.0 V for energy harvesting applications when using impact force test from freefall drop plasticine of 0.2 N was applied to the thick film

An Experimental Investigation Of Piezoelectric P (VDF-TrFE) Thick Film On Flexible Substrate As Energy Harvester

This paper proposes an experimental investigation of energy harvester using poly(vinylidene fluoride-trifluoroethylene) or P(VDF-TrFE) thick-film on flexible substrate by using print screen and rod method. Polyester film being used as the substrate where a sandwiched layer of electrode-piezopolymer-electrode thick film is deposited on. The thick-film is then annealed at 100°C and polarized at 100 V for the film with a thickness of about 18µm, being inspected under EDX, FESEM and XRD. The fabricated energy harvester piezoelectric is able to generate a maximum output power of 4.36 µW at an externa l electrical load of 1 kΩ with a maximum peak-to-peak of about 3.0V when an impact free-fall force of 0.2N was applied on the thick-film