Study on Screen Printable Color Paste Formulation for Color Silicon Solar Modules

Photovoltaic (PV) modules are incorporated into buildings as constitutional elements in building integrated PVs (BIPVs). BIPVs are evident in daily life as various forms on the roofs or skins of buildings. However, their mediocre color (typically black), has led to poor public acceptance. The development of color BIPVs is required to bestow aesthetic value to buildings. Coloring has been primarily achieved using expensive vacuum deposition processes. However, screen printing is becoming widely recognized as a highly competitive manufacturing technique for the fabrication of color BIPVs. Superior characteristics of screen printing include low cost, simplicity, and scalability. In this study, the formulation of color pastes using light interference pigments for screen printing is explored, because the success of screen-printed color BIPVs primarily depends on printability of these pastes. The screen printability of color pastes based on a commercially available two-part liquid paste and an in-house developed carrier vehicle was evaluated. The relativePV conversion efficiency of a color silicon solar module was 90% compared to a reference silicon solar module

Reinforcement of polypropylene with alkali-treated sugarcane bagasse fibers: Mechanism and consequences

Polypropylene composites were prepared from neat and alkali-treated sugarcane bagasse fibers. The results showed that alkali treatment leads to an increase in composite stiffness and strength. A maximum is achieved in these properties at around 5 wt% NaOH content of the treating solution. The increase in properties was assigned to the improvement in inherent fiber characteristics. Acoustic emission testing and electron microscopy showed that the two main local deformation processes related to the fibers are their fracture and debonding; the latter is accompanied by the shear yielding of the matrix. Increased inherent strength of the fibers results in an increase in the fracture initiation stress and fracture energy of the composites. Interfacial adhesion has a slight effect on stiffness, but more significant on strength and impact resistance. Changing adhesion modifies the relative importance of local deformation processes, the number of debonding events decreases, while fiber fracture increases with increasing adhesion. Increased interfacial adhesion improves stress transfer and the load bearing capacity of the fibers as well, but suppresses matrix yielding. Alkali treatment increases inherent fiber strength, which can be directly correlated with composite strength