TRANSPORT POLYMERIZATION FOR MATERIALS SYNTHESIS A Dissertation Presented by ZHIXIANG LU Submitted to the Graduate School of the University of Massachusetts Amherst in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY September 2006 Polymer Science and Engineering UMI Number: 3242104 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion.
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Box 1346 Ann Arbor, MI 48106-1346 © Copyright by Zhixiang Lu 2006 All Rights Reserved TRANSPORT POLYMERIZATION FOR MATERIALS SYNTHESIS A Dissertation Presented by ZHIXIANG LU Approved as to style and content by: Chit Thomgs J. WicCarthy, Chair “Kenneth R. Carter, Member —~ Dhandapani Venkataraman, Member Shaw Ling Hsu, Department Head Polymer Science and Engineering To my parents ACKNOWLEDGMENTS I would like to thank my advisor, Prof. McCarthy for his guidance, patience, encouragement and support throughout my studies.
I am grateful that he enabled me to come to this department and stay in his group. I also want to thank my committee members, Prof. Carter and Prof. Dhandapani Venkataraman for their valuable suggestions on my current research and future career.
Many thanks to Prof. Shaw Ling Hsu, Prof. Wei Chen and Prof. Tripp for their help while I was in Amherst and Orono.
The McCarthy group is my second family, I had a lot of fun when I was fishing with Kevin on ice, and I enjoyed talking about science with Jay, Sung-In and Margarita. I want to express my gratitude to Taehyung for handling my GPS; Kevin, Margarita and Xingiao for their unselfish help in the lab; Ebru for the help during my job-hunting; Jung- Ah, Lichao and Jianxin for their assistance in the preparation of my dissertation; and Yufeng for discussing the modification of my Pingpong rackets using PDMS. I also want to thank Xiaoying, Scott, Joonsung, Dalton, Bokyung, Ike, and Misha for their friendship. I will feel guilty if I don’t thank Jacob Hirsh; everything was easier when Jack was in the lab.
I would like to thank all the Faculty and Staff of PSE, especially Eileen and Vivien for making everything smooth and straightforward. I need to thank Louis Raboin for his help on TEM and SEM operation, and most importantly I couldn’t catch so many trout without his fishing tips. I also want to thank Ting Xu and Zhiqun Lin for their help. Finally I want to thank my parents and sisters back home, I could not have come this far without their love and support.
ABSTRACT TRANSPORT POLYMERIZATION FOR MATERIALS SYNTHESIS SEPTEMBER 2006 ZHIXIANG LU, B., FUDAN UNIVERSITY Ph., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Thomas J. McCarthy Ultrathin (10 nm ~ 1 pm) poly(ethyl 2-cyanoacrylate) (PECA) films were prepared on flat surfaces via vapor deposition without experiencing the liquid phase. System pressure, monomer temperature, as well as surface initiators were studied in the process of controlling the thickness and roughness of polymer films. The growth of poly(ethyl 2-cyanoacrylate) film from patterned initiating surfaces resulted in patterned polymer films.
Bulk and surface modifications have been studied in this dissertation to expand the application of poly(ethyl 2-cyanoacrylate) thin films. Polymer/metal composites were prepared using supercritical carbon dioxide. It was found that platinum formed homogeneous particles in poly(ethyl 2-cyanoacrylate) films, when poly(ethyl 2- cyanoacrylate)/poly(para-xylylene) (PPX) multilayer thin films were used as substrate for the platinum deposition, particles formed continuous layer in PECA layer while Transmission electron microscopy (TEM) did not show any platinum particles in PPX layer, which enabled the preparation of alternative conducting-isolating layers. vi Different functionalities can be introduced to the surface of poly(ethyl 2- cyanoacrylate) films after anhydrides, isocyanates and acyl chlorides reacted with PECA film which was reduced by LIAIH¿ and BH3.
X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurement indicated that the reaction yield was not high, but for special applications, this method may still be useful. Vapor deposition of ethyl 2-cyanoacrylate was also applied to the nano channels of anodized aluminum membrane (AAM). PECA layers with different thicknesses can be obtained on the inner wall of the nano channels by tuning vapor flow rate, temperature and vapor deposition time. PECA nanotubes were obtained after the removal of the anodized aluminum membrane.
PPX/PECA coaxial nanotubes with PPX-outer shell and PECA-inner shell were prepared by using vapor deposition of ethyl 2-cyanoacrylate (ECA) on the AAM-supported PPX nanotubes. Platinum deposition has been applied in the coaxial PPX-PECA nano tubes, platinum particles can be seen by SEM and TEM in the PECA layer or on the PECA inner surface. Gold nano particles were also formed inside of the PECA nanotubes using electroless gold deposition. vii TABLE OF CONTENTS Page ACKNOWLEDGMENTS.1 Solution polymerization of cyanoacryÌafe.2 Vapor deposition of poly(ethyl 2-cyanoacrylate) .3 Stability of poly-ơ-cyanoacryÌAf€.4 Application of poly(alkyl cyanoacryÌaf€)s.
- -- HH HH gu te 10 2. dc 0 SH TH HH ke 10 2.3 Cleaning of silicon Wafers.4 Modification of silicon WAaÍ€TS. óc HH HH ket 12 2.1 One-step modification.2 Two-step modificafiOf.3 Small molecule amines .4 Vapor deposition of PECA on silicon Wafers.5 Patterned initiator SUTÍaC€S.4 Results and Discussion .1 Modification of silicon WAÍ€TS. cu ng ng re 17 2.1 Surface-bound initiators on silicon waf€rs.2 Effect of temperature on the vapor deposition of PECA.3 Poly(ethyl 2-cyanoacrylate) thin films from different initiating Ji se.4 Effect of system pressure on vapor deposition of PECA.5 Vapor deposition of PECA on tris- TMSCI modified silicon M5 1 .6 ECA polymerization on patterned surfaces.
46 METAL DEPOSITION IN THIN POLYMER FILMS. HT TH TT TH HH HH gu ng 48 3.---- TH TT HH TT HT TH 52 3.3 Synthesis of PECA ÍiÏms.- HH TH ng key 53 3.4 Synthesis of poly(para-xylylene) thin filmas.5 Surface modification of PPX film.6 Multilayer polymer thin films.7 Pt deposition in polymer thin fñlms.8 Ag and Ni deposition in PECA thin films .3 Results and ÏDIsCuSSIOI. HH HH ng TH 57 3.1 Pt deposition in poly(ethyl 2-cyanoacrylate) thin films.2 The effect of temperature on platinum particle size .3 The effect of precursor concentration on platinum particle s1ze.4 Reduction with and without carbon dioxide.5 PPX surface mOdifiCafIOT\. Án HH ng gi, 63 3.6 Platinum deposition in PPX-PECA multilayer thin films.7 Silver and nickel deposition in poly(ethyl 2-cyanoacrylate) thin 01 1.
TH HH TH TT HH HH 68 3.- Án HH HH HH ng TH g9 000 69 SURFACE MODIFICATION OF POLY(ETHYL 2-CYANOACRYLATE) FILM.- HH HH HH HH TH HH gu kh 74 4.1 Surface modification of polymer fIÌms.2 Surface modification of poly(ethyl 2-cyanoacrylate) film.- TH TH ng TH HH kg 77 4. HH HH ớt 77 4.1 Reduction of PECA film by LIAIH¿.2 Vapor phase reaction of HFBC with LiAlH,-reduced PECA file ccceseteseeseecesesereesesesseesesessasseseesesseseons 78 4.3 Further modification of LIAIHa-reduced PECA films.4 PECA reduction with BH3 in diethyl ether at room {CTID€TAẦUTC oe 80 4.5 Modification of BH3-reduced PECA .3 Results and ÏDISCUSSIOTI.- SH ng TH HH HH nà nhiệt 81 4.1 PECA reduced by LIAIH¿ in diethyl ether.2 Vapor reaction of HFBC with LiAlH4-reduced PECA films.3 Solution reaction of HFBC with LiAlH,-reduced PECA films.4 Reduction of PECA film by BH; in diethyl ether. ch HH HH TT 0090 C1 102 4. "HH TH HT TT HT HT HH0 001510 103 PREPARATION OF SMALL POLYMER OBJECTS USING ANODIZED ALUMINUM MEMBRANES.
HH HH nh HH ng nưy 106 5.- << c1 HH TH HT g9 Kg 106 n9 2.2 Anodized aluminum membranes (AAM).- ác HH HT go HT 70t 109 5.-- Q0 LH TH TT n e 109 5. Án HH gu kh 109 5.3 Modification of anodized aluminum membranes (AAM).4 Vapor deposition of poly(ethyl 2-cyanoacrylate) on AAMs.5 Vapor deposition of poly(p-xylylene) on AAMs.6 Surface modification of the poly(p-xylylene) layer on AAMs.7 Preparation of poly(ethyl 2-cyanoacrylate)/ poly(p-xylylene) coaxial nanotubes using AAMS as templafes.8 Metal deposition in PPX/PECA nanotubes.3 Results and DDIsCUSSIOTI. Ăn TH ng ng tt 114 5.1 Vapor deposition of PECA on AAMs.1 Nitrogen flow rate oo.2 The effect of the temperature on the vapor deposition © Of PECA on AAM.3 The effect of vapor deposition time on the deposition Of PECA on AAM. - --- -- HH ng HT ng 131 5.3 PPX/PECA coaxial nanotubes.4 Platinum deposition in PPX/PECA coaxial nanotubes.
- HH HH TH HH HH HH TH kg 142 h2. 143 APPENDICES A CALCULATION OF PECA THICKNESS ON AAM. he 147 B ELECTROLESS GOLD DEPOSITION IN PECA NANOTUBES.- - c1 HH nh HT HH Ho HT c0 T0 157 xi LIST OF TABLES Table Page 2. Thickness of aminosilane layers on silicon wafer.
Silicon wafers modified by different aminosilanes and amines. Water contact angles and root-mean-square roughness (Rq) of the silicon wafers modified by tris(trimethylsiloxy)chlorosilane for different periods Of tI€. - ch HH ng HH HT HT Hiện 33 2. Water contact angles and Rq of silicon wafers treated with tris-TMSCI for different periods of time followed by 24 hour-APDMES vapor Phase r€aCtIOT.- HH HH HH HT TT TH ch ke 33 3.
Surface modification of PPX film. Water contact angles of PECA films reduced by LIAIH¿. The thickness change of the PECA films after LiAlH, reduction. Water contact angles of the LiA]H4-reduced PECA modification with s0: 0.
XPS data of LiAlH4-reduced PECA after modification with HFBC. XPS data and root-mean-square roughness of LiAlH4-reduced PECA surface modified with HFEBC. -0 HH» ng HH ng ng th 91 4. Root-mean-square roughness (Rq) of the 1 hour LiAlH4-reduced PECA modified with acyl chlOT1d€S.- cv SH ng re 91 4.
XPS data and water contact angles of the PECA film modified with acyl chlorides, an anhydride and 1socyanaf€S. Thickness and contact angles of BH; reduced PECA films before and after HF BC modifiCAtiOT. XPS data of BH3-reduced PECA film modified with HFBC. Modification of the 2-hour BH; reduced PECA.
XPS data of 2 hour BH3-reduced PECA film after modification. 101 xii LIST OF FIGURES Figure Page 2. Initiation mechanism of the polymerization of ethyl 2-cyanoacrylate by primary, secondary, and tertiary aIm1rI€S. Proposed mechanism of ethyl 2-cyanoacrylate polymerization from an activated surface initiator SI{©.
cu HH ng HH ng in " 8 2. Apparatus for vapor deposition of poly(ethyl 2-cyanoacrylate). Vapor deposition of PECA on patterned initiating surface. Structures of aminosilanes: 1.
Silanization of silicon wafers with different aminosilanes. Thickness (A) and root-mean-square roughness (B) of PECA films grown at 35 °C from (¢) APDMES (m) (N, N-diethyl-3- aminopropyl)trimethoxysilane (A) N- methylaminopropyltrimethoxysilane (®) 2- (trimethoxysilylethyl)pyridine - treated silicon wafers. Thickness (A) and root-mean-square roughness (B) of PECA films grown at 35 °C from (¢) ethylene diamine (m) diethylamine (A) triethylamine and (®) pyridine - treated silicon Wafers. Thickness (A) and root-mean-square roughness (B) of PECA films obtained from APDMES-modified silicon wafers under different system pressures with monomer at 35 °C for 20 minutes.
Vapor deposition of PECA on APDMES/ tris(trimethylsiloxy)s1lyl- chlorosilane (tris-TMSC]) modified silicon wafÍer. Nitrogen concentration on the surfaces of silicon wafers treated with tris-TMSCI for different periods of time followed by 24 hour- APDMES vapor phase reaction (XPS 15° take off angle). Thickness of PECA films after 2-hour deposition at 35 °C, 400 mm Hg on silicon wafers treated with tris-TMSC] for different periods of time followed by 24 hour-APDMES vapor phase reaction. Advancing (®) and receding (m) contact angles of PECA films formed on silicon wafers treated with tris-TMSC]I for different periods of time followed by 24 hour-APDMES vapor phase reaction.
AFM images of the PECA films deposited at 35 °C, 400 mm Hg for 2 hours on silicon wafers treated by tris-TMSC] for: 1.