## 1 Introduction  
Many manufacturing industries, such as printing, leather, textile finishing, pharmaceutical companies and plastic, are customary users of dyestuffs. It has been clearly demonstrated that almost 10 to 15% of the dyes are released with the effluent, leading to water contamination [1]. Due to their complex aromatic molecular structure, dyes are chemically stable to biodegradation, heat, light and oxidizing agents, resulting in environmental persistence and bioaccumulation [2]. By a cascading effect, they contribute to environmental pollution in trace quantities and have an impact on ecosystems [3] and human health [4]. Meanwhile, different methods are already used to remove dyes from wastewaters, such as chemical coagulation [5], fungal decolorization [6], adsorption [7], membrane filtration [8] and degradation [9]. However, water treatment technologies require a longer treatment time and high operating costs. Much attention has been focused on the design and synthesis of new adsorbents to remove organic dyes from water. Adsorption seems to be the most discerning process due to several advantages, including a low cost, high efficiency, recyclable ability, production of non-toxic by-products, easy process and the recovering of the whole dye. To be a good adsorbent, the intended target must possess efficient adsorption abilities with respect to the dye but also a low water solubility and good processing performance. Literature reports the use of numerous adsorbents of organic or mineral origin with significant examples, such as silica nanoparticles [10, 11], activated carbon [12], zeolite [13], chitosan [14], nanocomposites [15] and cellulose [16]. The scientific community is increasingly concerned about the environment and the nature of the compounds used to prevent its contamination. Various derivativesof biomass were investigated and \(\beta\)-cyclodextrintrins (\(\beta\)-CD) seems to be promising, ecofriendly materials due to their low cost, chemical stability, high reactivity and safety. \(\beta\)-CD consists of seven glucopyranose units linked by \(\alpha\)-1,4-glucosidase bonds that can encapsulate guest molecules to form host-guest inclusion complexes [17]. Due to their ability to form inclusion complexes, CDs and their derivatives are widely used as drug carriers [18; 19; 20], in food formulations [21; 22] and in soil remediation [23]. However, \(\beta\)-CD can be used for the removal of organic dyes from water but its solubility in water limits its use in the native form. By organizing them in a network, water-insoluble polymers using a crosslinking agent, such as epichlorohydrin [24; 25; 26; 27], dicarboxylic acid [28] or isocyanate [29; 30], can be achieved to obtain an adsorbent. Depending of the experimental conditions during the polymerization reaction, water-soluble and water-insoluble polymers are generally obtained [31; 32]. Various applications of these polymers were reported, in particular for dye [33; 34; 35; 36], organic pollutants [37] and heavy metal ions removal [38]. Unfortunately, epichlorohydrin and isocyanates have a major drawback, in that they are known to be toxic and carcinogenic to humans and animals [39] and produce unsafe byproducts in the \(\beta\)-CD crosslinking process. Another point to consider is the chemical nature of the linker because \(\beta\)-CD does not have the same affinity for dyes. [PERSON] [40] suggested that \(\beta\)-CD polymers containing carboxylic acid groups efficiently remove methylene blue from water. Up to now, many papers have described the preparation of \(\beta\)-CD adsorbents with various linkers to remove dyes from water, but other non-toxic crosslinking agents should be tested. For example, polyethylene glycol (PEG) is widely used in drug delivery [41; 42], electronics [43], fluorescent detection [44] and tissue engineering [45] due to its harmlessness. Moreover, PEG can be easily functionalized with azides, thiols, carboxylic acids, hydroxyl and epoxides, making them attractive for organic synthesis. [PERSON] et al.