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PVP K30 (Tech-grade)
Kingcham
When the spherical silver powder used in the positive electrode silver paste of photovoltaic cells is prepared by liquid phase reduction method, PVP can form complex ions with silver ions, which affects the concentration of free silver ions and the reduction potential of ions, and thus affects the nucleation and growth rate. The improvement of particle morphology is due to the fact that PVP adsorption on the surface of metal particles reduces the surface energy of metal nucleus, so that the metal atoms generated after the reaction grow uniformly on the surface of the crystal nucleus, and it is easy to obtain spherical particles with uniform particle size. In addition, PVP adsorption on the surface of silver particles causes a steric hindrance repulsive potential energy between particles, which increases the barrier between particles sharply, thus preventing agglomeration between particles and making them highly dispersed. The higher the PVP concentration, the better the quality of silver powder. According to the Preparation of spherical Silver powder for Photovoltaic cell positive Silver Paste published by Shandong Academy of Sciences, when PVP concentration is low, the particle size of silver powder is very uneven, the morphology is not very regular, and agglomeration occurs, while when PVP concentration is high, the silver powder has uniform particle size, high dispersion and spherical morphology. Using 5% PVP solution as dispersing agent, spherical silver powder with good dispersion and uniform particle size (average about 1.5 um) can be prepared to produce 1g silver powder, which consumes about 0.8g PVP. According to the literature, if 50g PVP is dissolved in 950mL deionized water to make a 5%wt PVP solution, and then 100g silver nitrate is dissolved in it, about 63.5g silver powder can be produced theoretically. The theoretical quality ratio of silver powder output to PVP amount calculated accordingly is silver powder: PVP= 1:0.79. According to the new Open Source company announcement, PVP in silver powder percentage can reach 20%-50% depending on the individual craft.
When the spherical silver powder used in the positive electrode silver paste of photovoltaic cells is prepared by liquid phase reduction method, PVP can form complex ions with silver ions, which affects the concentration of free silver ions and the reduction potential of ions, and thus affects the nucleation and growth rate. The improvement of particle morphology is due to the fact that PVP adsorption on the surface of metal particles reduces the surface energy of metal nucleus, so that the metal atoms generated after the reaction grow uniformly on the surface of the crystal nucleus, and it is easy to obtain spherical particles with uniform particle size. In addition, PVP adsorption on the surface of silver particles causes a steric hindrance repulsive potential energy between particles, which increases the barrier between particles sharply, thus preventing agglomeration between particles and making them highly dispersed. The higher the PVP concentration, the better the quality of silver powder. According to the Preparation of spherical Silver powder for Photovoltaic cell positive Silver Paste published by Shandong Academy of Sciences, when PVP concentration is low, the particle size of silver powder is very uneven, the morphology is not very regular, and agglomeration occurs, while when PVP concentration is high, the silver powder has uniform particle size, high dispersion and spherical morphology. Using 5% PVP solution as dispersing agent, spherical silver powder with good dispersion and uniform particle size (average about 1.5 um) can be prepared to produce 1g silver powder, which consumes about 0.8g PVP. According to the literature, if 50g PVP is dissolved in 950mL deionized water to make a 5%wt PVP solution, and then 100g silver nitrate is dissolved in it, about 63.5g silver powder can be produced theoretically. The theoretical quality ratio of silver powder output to PVP amount calculated accordingly is silver powder: PVP= 1:0.79. According to the new Open Source company announcement, PVP in silver powder percentage can reach 20%-50% depending on the individual craft.