# An Updated Review: _Opuntia focus indica_ (OFI) Chemistry and Its Diverse Applications
## 3 Applications
### Application of Opuntia in Building Materials  
The application of OFI in construction materials has gained significant attention because of its ability to be a sustainable and eco-friendly alternative. OFI is easily cultivated in many areas, making it an instantly available resource for construction material applications. Findings have shown that _Opuntia_-dried pads, spines, and fibrous materials are used in roofs, furniture, natural adhesives in traditional construction, joining adobe bricks, making household objects, and in many other building raw materials, including wall panels, bio-composites, and insulations. The cladodes and stems are utilized to make insulating material with a high thermal ability and fire resistance. Further, plant fibers and bio-degradable materials are combined to make bio-composites with good mechanical properties. The admixture of resin with bio-silica grains (0.5% Vol.) was poured on a fixed, coated wax rubber mold; then, a layer of short OFI fiber (30% by volume) was carefully added to obtain composite material at 25 \({}^{\circ}\)C for 24 h and, subsequently, at 120 \({}^{\circ}\)C for 48 h. The results showed an enhancement in toughness strength, improved wear resistance, high tensile strength, and a significant increase in energy capacity storage (4.34 GPa and 34,371 life counts fatigue with a 0.71 loss factor) [107]. In another work, the OFI fiber of cladode (10% wt.) treated with alkali was applied in a (HDPE) high-density polyethylene matrix and demonstrated a rise in rigidity and the modulus of elasticity, while the addition of the maleic anhydride grafted 3, block Cs\({}_{8}\)H\(-\)(C\({}_{2}\)H\({}_{4}\)-C\({}_{4}\)H\({}_{8}\))-C\({}_{8}\)H\({}_{8}\) copolymer also enhanced the plasticity, ductility, and heat properties. The green composite OFI/HDPE is applied as an alternative material in construction products [108]. For mortar preparation, OFI mucilage (1:1 cladode/H\({}_{2}\)O ratio), Mexican standard cement (1:3 ratio with silica sand), and liquid (H\({}_{2}\)O + mucilage) (650 mL) are used with different concentrations of the total volume of OFI mucilage (1.5 to 95%). The results show that OFI mucilage decreases mortar (cement-based) porosity, enhances durability, and increases compressive strength and electrical resistivity. Additionally, it improves mechanical strength and increases its lifespan [109; 110]. The OFI mucilage, cooked OFI mucilage and exudate OFI mucilage (4%, 8%, 15%, 30% w/m concentration), and OFI dehydrated powder (1%, 2%, 4% cement by sand mass replacement) are used to calculate the durability of concrete for 30, 90, 180, and 400 days. The OFI dehydrated powder improved chloride transport and decreased the RCP (rapid chloride permeability) index by 10%. The exudate OFI nucilage improved the 30% RCP index and 20% durability index, while for mixture controlling, cooked OFI nucilage showed excellent results. OFI derivatives work like biopolymers (clogging sponges) in the matrix pores of cement, stopping the transport of H\({}_{2}\)O and chloride in concrete [111]. The cactus extract solution contains polysaccharides with a gluey character which were used in mortar to improve the sustainability, water absorption resistance, and plasticity and significantly reduce water absorption in the concrete. The cactus 100% solution was shown to be more effect in mortar and concrete as compared to the cactus 50% solution. The study demonstrates that natural biopolymers sugarcane bagasse [112], straw, wood, stalks with lime, bamboo, and animal dung [113]--were utilized in construction materials as reinforcing agents to enhance the strength and durability of structures like adobe buildings, mud bricks, and wall plasters in ancient times [114].  
In Table 8, we have compiled a comprehensive summary of the diverse applications of various parts of _Opuntia ficus indica_, including cladodes, fruits, flowers, seeds, skins, and mucilage.