University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 8-2005 Synthesis and Applications of Monolithic HPLC Columns Chengdu Liang University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Chemistry Commons Recommended Citation Liang, Chengdu, "Synthesis and Applications of Monolithic HPLC Columns. " PhD diss., University of Tennessee, 2005. https://trace.tennessee.edu/utk_graddiss/2233 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Chengdu Liang entitled "Synthesis and Applications of Monolithic HPLC Columns." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Chemistry. Georges A Guiochon, Major Professor We have read this dissertation and recommend its acceptance: Sheng Dai, Craig E Barnes, Michael J Sepaniak, Bin Hu Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) To the Graduate Council: I am submitting herewith a dissertation written by Chengdu Liang entitled, “Synthesis and applications of monolithic HPLC columns.” I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Chemistry. Georges A Guiochon _______________ Major Professor We have read this dissertation and recommend its acceptance: Sheng Dai __________________ Craig E Barnes __________________ Michael J Sepaniak __________________ Bin Hu __________________ Accepted for the Council: Anne Mayhew Vice Chancellor and Dean of Graduate Studies (Original signatures are on file with official student records.) Synthesis and applications of monolithic HPLC columns A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Chengdu Liang Augest, 2005 Acknowledgements Many people offered their generous help to the completion of this dissertation, far too many to name, but a few of you deserve singling out. First and foremost, many thanks to Dr Georges Guiochon for guiding me into the research field of chromatography. His advices inspired me to carry out this challenging project. I would like to express my gratitude to my dissertation advisor Dr Sheng Dai for his friendship and mentorship. I would like to thank him for his elaborative instructions in every detail of my research work. I also want to thank Dr Sheng Dai for the opportunity to work and learn in a supportive environment, where I was given the full freedom to develop my research skills. Thanks also to my committee members, Dr Craig Barnes, Dr Michael Sepaniak, and Dr Bin Hu, who spent their precious time on reading and commenting my dissertation. Many thanks go to the members, past and present, of the Dai group and the Guiochon group. It’s been wonderful working with these two groups of great people, who are majoring in two deferent subjects. Special thanks to Dr Shannon Mahurin and Mrs. Michelle Pawel for their language help in Chapter 5, and 7. Last but not least, a special thanks to my family for their continuous encouragements and spiritual supports during my study in the U.S. Their love is beyond words. ii Abstract Silica and carbon monolithic columns were synthesized and modified for liquid chromatography applications. Column configurations and cladding techniques were investigated in detail. Three novel approaches have been developed for the synthesis of bimodal porous rods. Out of these three methods, gel-casting was adopted for the synthesis of silica monoliths with ordered mesopores and uniform macropores; the use of colloidal templates and dual phase separation has been successfully implemented for the synthesis of carbon monoliths with well-controlled meso- and macro- porosities. The formation of mesopores in carbon materials has been further studied in the microphase separation of block copolymers. Electrochemical modification of carbon monoliths was discovered to be an efficient method for converting covalently bonded functionalities to carbon monoliths. N,N’-diethylaminobenzene has been attached to carbon surface for the separation of proteins and protein digests. The performances of carbon-based monolithic columns were studied intensely through frontal analysis and Van Deemter plot. Temperature and pressure effects were also investigated in carbon-based columns. The density of bonding on the modified carbon monoliths was characterized by thermogravimetric analysis. iii CHAPTER 1: INTRODUCTION .......................................................................................................................1 1.1 The background of chromatography................................................................................................1 1.2 Components of an HPLC system......................................................................................................3 1.3 The history of particulate columns...................................................................................................5 1.4 The nature of monolithic columns....................................................................................................7 1.5 Development of monolithic columns ................................................................................................9 1.6 The classification of monolithic HPLC columns............................................................................11 1.7 Goals of this work..........................................................................................................................15 CHAPTER 2: CONFIGURATIONS OF MONOLITHIC COLUMNS .......................................................................18 2.1 New challenges associated with monolithic columns.....................................................................18 2.2 Polymer-lined stainless steel-tubing encasing ...............................................................................20 2.2.1 Materials for column fabrication ............................................................................................................ 21 2.2.2 General procedure for column encasing................................................................................................. 21 2.2.3 Discussion of the preparation procedure ................................................................................................ 22 2.3 Glass-shrinking encapsulation.......................................................................................................24 2.3.1 Setup and shrinking procedure for glass tubing...................................................................................... 25 2.3.2 Key points for glass shrinking................................................................................................................ 26 2.4 Polymerization encapsulation (polymer coating) ..........................................................................27 2.4.1 Materials for polymer coating ................................................................................................................ 27 2.4.2 General procedure for fabrication of polymer-coated monolithic columns ............................................ 28 2.4.3 Discussion of the polymer-coated column configuration ....................................................................... 29 2.5 Multicapillary-array configuration for microbore monolithic columns ........................................29 CHAPTER 3: PREPARATION OF MONOLITHIC SILICA COLUMNS VIA GEL-CASTING ......................................32 3.1 Silica monolithic columns with ordered mesopores and tunable macrochannels..........................32 3.2 The fabrication of silica monolithic columns.................................................................................35 3.2.1 Materials and instruments ...................................................................................................................... 35 3.2.2 The synthesis of mesoporous silica particles.......................................................................................... 36 3.2.3 Gel-casting of silica particles into a monolithic rod ............................................................................... 36 iv 3.2.4 Fabrication and surface modification of silica columns ......................................................................... 37 3.2.5 HPLC application................................................................................................................................... 38 3.3 Results and discussion ...................................................................................................................38 3.4 Conclusion .....................................................................................................................................43 CHAPTER 4: CARBON MONOLITHIC COLUMNS MADE BY COLLOIDAL TEMPLATES......................................44