Dakota Seeds and Antimicrobial Paint

1. Dakota Seeds and Antimicrobial Paint Matthew Tanner and Dan Engebretson The University of South Dakota Dakota Seeds What is it? Dakota Seeds is a program designed to assist both students and businesses in the internship process. By using the website, www.DakotaSeeds.com, employers are able to post internships for both undergraduate and graduate students to access. Then the traditional interview and hiring processes fill these internships. Assistance also comes in the form of grants. Dakota Seeds provides a grant that will cover up to one-half of the positions wages with a maximum of $2,000 for undergraduate or graduate student internships, and $8,000 annually for masters degree students, and $10,000 annually for PhD students who are working as a research and development assistant. How it Works Company completes application for participation in the program Application is reviewed and approved by the South Dakota Workforce Development Council Position is posted to the Dakota Seeds website Students apply for positions Companies interview and hire Company signs letter of agreement and completes W-9 form Company submits completion report and request reimbursement Reimbursement is sent to the company Company responds to follow-up survey How I Benefited Through the Dakota Seeds program half of my internship with Prairie Scientific Innovations was paid for. Recent work from that internship is featured to the right. From: Dakota Seeds: Matching Students to Employers. Pierre, SD: Governor’s Office of Economic Development, 2011 Antimicrobial Paint • Introduction • Because of the fast growing need to control surface microbial contamination in residential, commercial, institutional, industrial, and hygienic applications, antimicrobial paints are experiencing tremendous growth [1]. • While a number of antimicrobial paints are commercially available, none of them can provide biocidal functions against bacteria (including drug-resistant species), mold, fungi, and viruses simultaneously. The narrow inhibiting spectrum reduces the effectiveness and limits the applications of the current antimicrobial paints. To solve this problem, a polymeric N-halamine latex emulsion was developed for use in antimicrobial paints by Cao and Sun, who also demonstrated the antimicrobial efficiency of the emulsion [2]. • The purpose of this study has been to characterize the physical properties of the antimicrobial paint with the N-halamine latex emulsion. To accomplish this the antimicrobial properties of the current batch of the N-halamine latex emulsion will be confirmed, followed by ASTM methods that will test for scrub resistance, washability, adhesion, and effects on color. • Materials • The N-halamine latex emulsion was made by the polymerization of monomer N-chloro-2,2,6,6-tetramethyl-4-piperidinyl methacrylate (Cl-TMPM) using a semicontinuous emulsion polymerization technique by Cao as previously described by Cao and Sun [2]. • Four different paints were selected for this study:Color Place latex semigloss house white, Wal-Mart Store, Inc.; HEALTH-KOTE® low odor interior eggshell latex white, Diamond Vogel Paints; Ceramic Coat low odor stain resistant flat white, O’Leary Paint; Ceramic Coat with Microban low odor stain resistant flat white, O’Leary Paint • Staphylococcus aureus (S. aureus; ATCC 6538) was obtained from American Type Culture Collection (ATCC) • Methods • The antimicrobial tests were performed using the method describe by Cao and Sun [2] and a contact time of 3 hours. • ASTM D2486-06: Scrub Resistance of Wall Paints, Method B • ASTM D4828-94: Practical Washability of Organic Coatings • ASTM D5179-02: Measuring Adhesion of Organic Coatings to Plastic Substrates by Direct Tensile Testing • ASTM E313-05: Calculating Yellowness and Whiteness Indices from Instrumentally Measured Color Coordinates Results Figure 3. Washability, wear, and friction tester • Discussion • The initial study of the combination with Cl-TMPM polymer latex emulsion with paint was performed with the Color Place latex semigloss. Confirmation of the antimicrobial properties, as well as the scrub resistance, were performed with Color Place paint for this reason. To demonstrate the effectiveness of this N-halamine latex emulsion against Microban, the current leading antimicrobial paint product, the O’Leary Ceramic Coat was also chosen because a version with and without Microban was made. • The difference between the scrub resistance of the Ceramic Coat with Microban (88.4 % ± 7.2%) and Ceramic Coat with Cl-TMPM (89.9 % ± 5.0 %) was not statistically significant (p-value = 0.55). There was a difference in the reduction in growth between the Ceramic Coat with Microban (70.6 % ± 33.8%) and Ceramic Coat with Cl-TMPM (26.1 % ± 31.4%) (p-value=0.0003).The most important result from the tests conducted with the Cl-TMPM polymer latex emulsion made on 10/1/10 was the lack of the total kill achieved by Cao and Sun in a previous study [2]. Several ideas were postulated to explain this result with the most likely being that the molecular weight of the polymer was too large. A new batch of the Cl-TMPM polymer latex emulsion was made and antimicrobial contact tests were performed to analyze this new emulsion. • The antimicrobial contact tests performed with the new batch of emulsion were much more favorable. A total kill was achieved using the Color Place paint while a 99.4 % ± 41.5%reduction in growth was seen with the HEALTH-KOTE. • With these results the antimicrobial effectiveness of the N-halamine latex emulsion in Color Place has been confirmed. Future work in this study will be the other ASTM methods with the Color Place paint as a base and the antimicrobial and physical characteristics of the N-halamine latex emulsion with other paints. • References • Schabrun S., Chipchase L. J. Hosp. Infect. 2006, 63, 239-245 • Cao Z., Sun Y. Polymeric N-Halamine Latex Emulsions for Use in Antimicrobial Paints. ACS Appl. Mater. Interfaces. 2009, 1, 494-504 *Cl-TMPM polymer latex emulsion made on 10/1/10 **Cl-TMPM polymer latex emulation made on 10/6/11 Fig 1. Failure point of antimicrobial paint during scrub resistance test Figure 2. Failure point of reference paint during scrub resistance test