The water shortage problem is one of the most challenges in the world that caused to call 21st century the \"water century\". Conversely, 97% of Earth\'s water is saline, thus the desalination process is the main strategy to overcome the water shortage problem. Among different methods, reverse osmosis (RO) membrane technology is one of the most popular water purification technologies, because of its properties such as the high salt rejection and permeation rates as well as their excellent chemical, thermal and mechanical stability. However, fouling is a major problem in the RO process as well as in other membrane processes. Membrane fouling negatively affects membrane performance by decreasing water permeability. As a result, the costs of membrane processes are increased by higher energy consumption and the frequent need for cleaning and maintenance. Many studies have been carried out to prevent the fouling in RO processes and various methods have been suggested to control membrane fouling. Membrane fouling can be broadly categorized into inorganic fouling, organic fouling, and biofouling. Inorganic fouling is caused by the scale formation at the membrane surface and organic fouling by the deposition of organic foulants (such as surfactants and proteins) on the membrane surface. Biofouling is the undesired attachment of microorganism communities to a membrane surface. Bacteria adhered to the surface release extracellular polymeric substances (EPS) and consequently, a biofilm EPS matrix with embedded bacteria is formed. Membrane biofouling is a more serious problem than organic fouling, particularly in drinking water production and water treatment, because of the secondary pollutants generated as metabolic products of the bacteria that have attached and grown on the membrane surface. In addition, biofouling cannot be removed by chlorine treatment or backwashing, while inorganic fouling and organic fouling can be reversed. Generally, the antibiofouling properties are improved through two main strategies. These strategies are based on two important properties. The first strategy is attributed to antibacterial property. This strategy is also divided into biocide leaching (or release killing) and contact killing approaches. The second strategy is based on the antiadhesion property. In biocide leaching approach of the first strategy, the cytotoxic compounds are released from biocide chemicals embedded into the surface. Bacteria will be lysed in the feed solution while a membrane has release killing potential. Thus, the attachment of bacteria on the membrane surface is reduced. In the second approach (contact killing), the surface is modified by antibacterial materials such as antimicrobial peptides and chemicals with quaternary ammonium groups. Generally, the antibacterial properties of membranes are improved by the antibacterial agents including organic and inorganic compounds; however, organic antibacterial agents are limited in their applications because of low heat resistance and short lifetime. On the other hand, inorganic antibacterial agents have attracted considerable attention, because the materials show superior durability, low toxicity, good heat resistance and show high activity at low concentrations. Silver is a well-known inorganic antimicrobial agent with a particularly high antibacterial activity. Other inorganic materials used for these purposes include metal hydroxide such as Ca(OH)2, Mg(OH)2 and Cu(OH)2. In the second strategy (adhesion resistance), groups with the same electrostatic charge polarity as bacteria enhances the antiadhesion properties of the membrane surface through electrostatic repulsion between the bacteria and the membrane surface. Zwitterionic monomers, such as methacryloyloxyethyl phosphorylcholine (MPC), are chemicals with cationic and anionic groups on their backbone structures and are electrically neutral. These zwitterionic monomers are biocompatible and are known for their high hydrophilicity. Thus, grafting zwitterionic monomers onto a membrane surface is another method to improve adhesion resistance.