## 1 Introduction  
Pharmaceutical residues contaminated wastewater has been receiving attention from scientific and governmental organizations due to perceived threats to the environment and human health [1]. The leakage of pharmaceutical wastewater and its ingredients from the manufacturing process can enter the aquatic environment through wastewater treatments, therefore the varieties of pharmaceutical residues have already been found in surface water and ground water, which becomes a severe environmental problem owing to their toxicity, solubility, and pseudo persistence [2]. Clofibric acid (CFA), a xenobiotic metabolite of cholesterol-lowering pharmaceutical fibre drugs, is considered a representative pharmaceutical residue with a high level of environmental risk because it is often detected in the aquatic ecosystem [3; 4; 5]. Moreover, CFA imposes negative effects on metabolism, causes reproductive damage, and impacts the embryonic development and behavior of aquatic organisms, creating further risks to human health [6; 7; 8]. Therefore, various procedures have been used for the removal of CFA from industrial wastewater, such as photochemical degradation, biological processes, coagulation/flococulation/sedimentation, and filtration [9; 10; 11]. Nevertheless, these processes have limited use due to their need for expensive equipment as well as their high reagent or energy consumption. Adsorption is one of the potentially effective and economical techniques for removing pharmaceutical residues from wastewater because of its ease of operation, low capital and operating cost, and low energy consumption [9; 10; 11]. Mesoporous silica materials have received a lot of attention due to their excellent properties, including high surface area and large pore volume, good hydrothermal and mechanical stability, and high adsorption capacity [12; 13; 14; 15; 16]. Particularly, the mesoporous silica materials functionalized with amine groups (-NH\({}_{2}\)) are a class of solid sorbents for the removal of CFA from aqueous solutions [3; 17]. The previous study [3; 17] demonstrated that the amine-functionalized mesoporous silica exhibited good performance for the adsorption of CFA due to acid-base and/or ionic interaction and hydrogen bonding between the amino groups and carboxylic groups in CFA molecules. Nonetheless, the adsorption of organic molecules in aqueous solution is inefficient because water molecules are favorably adsorbed owing to the high density of residual silanol groups on the silica's surface. The surface modification of silica materials by the grafting of hydrophobic and adsorption active sites can enhance selective adsorption for organic or inorganic pollutants [3; 18]. However, the resulting mesostructured silicas suffer from a severe loss of surface area and pore volume by a non-uniform distribution of the organo-functional groups anchored within the mesoporous channels and on the mesopore mouth. The incorporation of hydrophobic polymer moieties into the mesostructure of silica is a facile approach to decrease the interaction of adsorbed water with the internal siliceous surface of mesopores, resulting in an enhanced affinity toward organic molecule adsorption in aqueous solution [13; 14; 15]. [PERSON] et al. [13; 16] prepared a series of mesoporous nanocomposites consisting of hydrophobic natural rubber (NR), a _cis_-1,4-polyisoprene, dispersed in the wormhole-like mesoporous silica (WMS). The nanocomposites obtained exhibited a well-ordered structure, large surface area and pore volume, and improved hydrophobicity. Although several studies have demonstrated that CFA can be removed effectively by mesoporous silica functionalized with organic amine groups, to the best of our knowledge, no report on the synthesis, characterization, and application of amine-functionalized NR/WMS nanocomposites for CFA removal from aqueous solutions exists.