Periodic Reporting for period 3 - ADOR (Assembly-disassembly-organisation-reassembly of microporous materials)
Période du rapport: 2021-10-01 au 2023-03-31
Microporous materials are an important class of solid; the two main members of this family are zeolites and metal-organic frameworks (MOFs). Zeolites are industrial solids whose applications range from catalysis, through ion exchange and adsorption technologies to medicine. MOFs are some of the most exciting new materials to have been developed over the last two decades, and they are just beginning to be applied commercially.
Over recent years the applicant’s group has developed new synthetic strategies to prepare microporous materials, including the Assembly-Disassembly-Organisation-Reassembly (ADOR) process. The ADOR process has shown to be an extremely important new synthetic methodology that differs fundamentally from traditional solvothermal methods. This process is important because it promises to enable the synthesis of materials that were previously thought to be impossible to make.
In this project the major objective is to overturn the conventional thinking in materials science by developing methodologies that can target both zeolites and MOF materials that are difficult to prepare using traditional methods – the so-called ‘unfeasible’ materials. The importance of such a new methodology is that it will open up routes to materials that have different properties (both chemical and topological) to those we currently have. Since zeolites and MOFs have so many actual and potential uses, the preparation of materials with different properties has a high chance of leading to new technologies in the medium/long term. To complete the major objectives of the programme we will look to complete four closely linked activities covering the development of design strategies for zeolites and MOFs (activities 1 & 2), mechanistic studies to understand the process at the molecular level using in situ characterisation techniques (activity 3) and an exploration of potential applied science for the prepared materials (activity 4).
Over recent years the applicant’s group has developed new synthetic strategies to prepare microporous materials, including the Assembly-Disassembly-Organisation-Reassembly (ADOR) process. The ADOR process has shown to be an extremely important new synthetic methodology that differs fundamentally from traditional solvothermal methods. This process is important because it promises to enable the synthesis of materials that were previously thought to be impossible to make.
In this project the major objective is to overturn the conventional thinking in materials science by developing methodologies that can target both zeolites and MOF materials that are difficult to prepare using traditional methods – the so-called ‘unfeasible’ materials. The importance of such a new methodology is that it will open up routes to materials that have different properties (both chemical and topological) to those we currently have. Since zeolites and MOFs have so many actual and potential uses, the preparation of materials with different properties has a high chance of leading to new technologies in the medium/long term. To complete the major objectives of the programme we will look to complete four closely linked activities covering the development of design strategies for zeolites and MOFs (activities 1 & 2), mechanistic studies to understand the process at the molecular level using in situ characterisation techniques (activity 3) and an exploration of potential applied science for the prepared materials (activity 4).
The work so far has concentrated on developing new methods by which the ADOR process can be applied, new materials that can be prepared and a study of the mechanisms. There has been significant progress in all three areas, split into four main activities.
In activity 1 we have prepared several new zeolites with interesting structures and also developed new methodology by which materials can be prepared using the approach. We have developed and published two new methodologies: the vapour phase transport (VPT) approach and mechanochemical synthesis. The VPT is essentially a gentler way to being the ADOR process. In our original ADOR method the disassembly method used either pure water or a acidic solution. This worked well if the intermediate layers were stable to hydrolysis but not so well when there was any instability in the layers. Using vapour instead of liquid as the hydrolysis medium has allowed us to develop method that does not destroy all the layers during the process and so can be used to prepare new materials. Mechanochemical synthesis is a method by which the energy required for hydrolysis is produced by a mechanical grinding using a ball mill. We have used this method to show that the ADOR process can be utilised in this way too. Interestingly, the final product can be different from those using the traditional ADOR process. Recently, we have also developed the reverse ADOR process, which allows us to build up structural units between the layers in a way that has not been done before. This work is accepted for publication in Materials Advances
In activity 2 we are extending the ADOR work to a new type of porous material - metal-organic frameworks (MOFs). The ADOR process has not been applied to MOFs in the same way as it has for zeolites. We are therefore developing the procedures to allow us to do this. We have been successful in preparing a material called SIMOF-3 which is a pillared layer type material, and we can show how the pillars between the layer can be disassembled and replaced by other linkers (i.e. reassembled)
In activity 3 we are looking at the mechanism of the process itself in great detail, We have used X-ray diffraction, NMR and pair distribution function analysis to develop a greater insight into four steps in the process. This has produced some valuable information, which we have published, on the process itself but has also thrown up some interesting new aspects for both zeolite and MOF chemistry. In MOFs we have shown some unusual breathing behaviour of materials and in zeolite swe have shown that the highly stable silica-based mateirals are in fact labile to water even at low temperatures. this was a significant suprise to the field and has significant consequences for how these important materials behave.
Activity 4 is just beginning and the results will be reported on in the future
In activity 1 we have prepared several new zeolites with interesting structures and also developed new methodology by which materials can be prepared using the approach. We have developed and published two new methodologies: the vapour phase transport (VPT) approach and mechanochemical synthesis. The VPT is essentially a gentler way to being the ADOR process. In our original ADOR method the disassembly method used either pure water or a acidic solution. This worked well if the intermediate layers were stable to hydrolysis but not so well when there was any instability in the layers. Using vapour instead of liquid as the hydrolysis medium has allowed us to develop method that does not destroy all the layers during the process and so can be used to prepare new materials. Mechanochemical synthesis is a method by which the energy required for hydrolysis is produced by a mechanical grinding using a ball mill. We have used this method to show that the ADOR process can be utilised in this way too. Interestingly, the final product can be different from those using the traditional ADOR process. Recently, we have also developed the reverse ADOR process, which allows us to build up structural units between the layers in a way that has not been done before. This work is accepted for publication in Materials Advances
In activity 2 we are extending the ADOR work to a new type of porous material - metal-organic frameworks (MOFs). The ADOR process has not been applied to MOFs in the same way as it has for zeolites. We are therefore developing the procedures to allow us to do this. We have been successful in preparing a material called SIMOF-3 which is a pillared layer type material, and we can show how the pillars between the layer can be disassembled and replaced by other linkers (i.e. reassembled)
In activity 3 we are looking at the mechanism of the process itself in great detail, We have used X-ray diffraction, NMR and pair distribution function analysis to develop a greater insight into four steps in the process. This has produced some valuable information, which we have published, on the process itself but has also thrown up some interesting new aspects for both zeolite and MOF chemistry. In MOFs we have shown some unusual breathing behaviour of materials and in zeolite swe have shown that the highly stable silica-based mateirals are in fact labile to water even at low temperatures. this was a significant suprise to the field and has significant consequences for how these important materials behave.
Activity 4 is just beginning and the results will be reported on in the future
In activities 1,2 and 3 there have been some significant advances beyond the state of the art as described above. We expect these developments to be continued. In particular activity 2 is showing great promise for some new applications in the area of MOF chemistry. The development of industry-friendly materials is the next major goal (activity 4) and we will endeavour to develop this are of the project significantly over the next year or so. Indeed, there has already been one, albeit unfinished aspect of this activity that we hope could be patented and then further exploited.