Metal oxides possess a high chemical and mechanical stability making them ideal support materials in several applications like catalysis and separations. Unfortunately, metal oxides don't have controllable selective interactions as only hydroxyl groups are present on the surface. Organic surface modification can solve this, creating versatility and affinity. The most applied surface modification method is organosilylation, developed for silica materials. However, silica has a limited chemical stability and a necessary evolution to robust and stable supports is needed for several in processes applications such as separation and purification. Titania and zirconia are good and robust alternatives for silica but, organosilylation results in unstable bonding of the functional groups. New and alternative methods like the organophosphonic acid modification and the recently co-developed (by UA and VITO) patented Grignard modification are highly promising, resulting in unique surface properties and separation performance. These high potential organically surface modified materials can open new opportunities in affinity driven separation processes, tailor made and highly selective induced by their surface properties. Nevertheless, thorough fundamental insights in the influence of synthesis/modifications conditions and reagent types on these physico-chemical surface properties and the resulting interactions between surface and surrounding molecules is lacking, certainly for functional groups other than aliphatic hydrocarbons. This is exactly the aim of this work: first the impact of synthesis conditions, type of modification method and functional groups on the physico-chemical surface properties are being unraveled allowing controlled surface properties. Secondly, differences in the surface properties that have an impact on the interactions of the surface with probe molecules will be identified. This DOCPRO4 will thus create the crucial fundamental knowledge to correlate synthetic control to physico-chemical properties and molecular interactions of organophosphonic acid and Grignard modified metal oxides.