###### Abstract
These organic materials usually have a high adsorption capacity, but they also take a long time to reach adsorption equilibrium and are less physically stable in aqueous solutions [4]. MOFs can also be defined as composite materials, but they are also physically unstable in aqueous solutions. In recent years, many researchers have shown great interest in alternative composite materials for uranium removal. For example, silica-based composites are gaining attention owing to the low cost and physical stability of silica spheres [30; 31]. In this work, silica spheres and resins are combined to prepare composite materials. In addition, environmental water systems contain many interfering ions. The chemical form of uranium in these systems needs to be considered in the adsorption process using the synthesized silica-based resins. The chemical form of uranium in environmental water systems is influenced by pH and various coexisting ions. When the pH of environmental water systems is 6.5-8.5, the uranyl ion readily combines with carbonate to form the UO\({}_{2}\)(CO\({}_{3}\))\({}_{2}\)\({}^{2-}\) and UO\({}_{2}\)(CO\({}_{3}\))\({}_{3}\)\({}^{4-}\) anions [11]. Environmental water systems contain a large number of calcium ions. Consequently, UO\({}_{2}\)(CO\({}_{3}\))\({}_{3}\)\({}^{4-}\) readily reacts with Ca\({}^{2+}\) to form CaUO\({}_{2}\)(CO\({}_{3}\))\({}_{3}\), which does not contribute to the adsorption of uranium [4; 30]. The concentrations of calcium and magnesium ions vary regionally. [PERSON] [32] found that in some regions, the calcium ion concentration reached 500 mg/L and was accompanied by sodium, potassium, sulfate, and carbonate ions. Therefore, the designed ion exchange materials still exhibited high uranium adsorption efficiency even in the presence of high concentrations of interfering ions. According to the soft and hard acid-base theory, the uranyl ion is considered a hard acid. Thus, the functional groups of the hard base ligands should contain as many nitrogen or oxygen atoms as possible. Therefore, research into uranium adsorption using polyamine resins has increased in recent years. For example, [PERSON]'s study [33] on uranium removal using PS-N-P resin--prepared by amine-modified P,P-dichlorophenylphosphine--demonstrated a saturated adsorption capacity of 97.60 mg/g and an adsorption efficiency of 99.72% for uranium at pH 5. [PERSON] [34] studied the preparation of polyamine-functionalized ion exchange resins for uranium removal and examined how the maximum adsorption capacity varied with the polyamine chain length. The maximum adsorption capacity was 269.50 mg/g, and all resins could extract over 86% of uranium from solutions at pH 1-6. [PERSON] [30] studied the preparation of a novel silica-based anion exchange resin (SAER) for removing uranium from drinking water and found that SAER had a relatively low pressure loss in a packed column and could adsorb uranium with an efficiency of over 80% in a working solution containing 40 mM Na\({}_{2}\)SO\({}_{4}\). In the studies by [PERSON] and [PERSON] [33; 34], the solution environment in which the resin adsorbed uranium was relatively simple; however, many interfering ions existed in the environmental water system, which was a challenge for the adsorption of uranium. [PERSON] [30] examined the adsorption efficiency of the resin in real water samples and did not study the relationship between the chain length of the polyamine resin and the adsorption performance. Therefore, in the present study, three types of silica-based polyamine resins with different chain lengths were successfully synthesized. A series of characterizations and evaluations of the adsorption properties of these resins were also completed. The relationship between the polyamine chain length and uranium adsorption efficiency was investigated. Additionally, the adsorption efficiency of the polyamine resin SiPMA-TETA in environmental water systems was studied. This research provides valuable insights for the synthesis of high-performance silica-based composite resins.