# Metal-Organic Frameworks as Promising Textile Flame Retardants: Importance and Application Methods
## 4 Metal-Organic Framework
### Application of Metalorganic Materials in Textiles  
With the advent of nanotechnology, various methods for functionalizing textiles have been explored, and metal-organic frameworks (MOFs) have great potential for development as they allow substrates to acquire new properties for use in various fields. Classified as chemical finishes, MOFs can be adhered to the polymeric mass of fibers or fixed to the final textile substrate. [PERSON] et al. [92] summarize recent MOF/fiber fabrication methods and applications. In addition to directly dipping the substrate into or dispersing it in MOF particles, the techniques for attaching the structures to the final textile substrate focus on continuous processes such as dip-pad-dry, direct synthesis (in situ growth), and layer-by-layer (LBL) assembly. In addition to these continuous processes, plasma, sol-gel, and spray technologies are gaining importance in the application MOFs to substrates. Chemical modifications can also be made to the textiles prior to contact with the organometallic structures, which can promote the formation of reactive groups such as carboxylates and hydroxyl groups, allowing the nucleation of MOFs in the fibers [92]. Figure 2 shows the main continuous processes used for MOF-textile adhesion.  
The dip-pad-dry process is a common and suitable method for treating cellulosic fabrics, in which a solution is used to fill the finishing liquid [93]. The dip consists of immersing the fabric in the finishing liquid, the pad refers to the act of passing the fabric through cylinders with stable pressure and speed to help the tex  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Functionality** & **MOF** & **References** \\ \hline Antibacterial & HKUST-1/CF & [84] \\ CuBTC & [85;86] \\ Fuel purification & CuBTC & [87] \\ Antimicrobial & Cu(BDC) & [77] \\ Integrated radiative cooling and photocatalytic & ZIF-8 & [88] \\ antibacterial properties. & UV protection & UIO-66 & [45] \\ Chemical protection & UIO-66 & [89;90] \\ Adsorption of water contaminants & ZIF-8 & [91] \\ \hline \hline \end{tabular}
\end{table}
Table 2: _Cont._  
Figure 2: Processes for applying MOF to textiles: (**a**) dip–pad–dry; (**b**) direct synthesis (depletion); (**c**) layer-by-layer; (**d**) printing.  
finishing liquid evenly. Drying is the process of drying the moisture contained in the fabric and retaining the amount of finishing liquid required by the process.  
It is also possible to synthesize the MOF on the textile substrate so that during the process of forming the structures, the fabric is immersed in the reagents, thus achieving direct synthesis on the fabric through exhaustion. It is also possible to apply MOFs layer-by-layer, which is a technique of alternating solutions to make multilayer coatings, with nanoscale thickness control of the films generated on the surface of the material [94]. Table 3 shows examples of methodologies used to functionalize textiles using MOFs. The LBL technique is a process that was developed in the 1990s and is produced by alternating deposition of the tissue in charged solutions, as well as electrostatic interactions, hydrogen bonds, covalent bonds, and donor-acceptor interactions that support this assembly [95; 96].  
It is also possible to attach the MOF to the substrate without using water/solvents as a transport medium. This is the case with embossing, which can contribute to the adhesion of organometallic materials with the help of resins incorporated into the embossing paste that crosslink with the textile. This ensures complete fixation by creating a kind of film under the surface. The table shows the methodology used in the work, including the MOF applied, the composition of the material, and the functionality achieved.