Increasing Chemistry Content Engagement by Implementing Polymer

Oct 5, 2018 - Mastery of core chemistry content is a degree requirement for several STEM majors. Gatekeeper courses, like general and physical chemist...
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Cite This: J. Chem. Educ. XXXX, XXX, XXX−XXX

Increasing Chemistry Content Engagement by Implementing Polymer Infusion into Gatekeeper Chemistry Courses Cherie M. Avent,*,† Ayesha S. Boyce,† Richard LaBennett,‡ and Darlene K. Taylor‡ †

Department of Educational Research Methodology, University of North Carolina at Greensboro, Greensboro, North Carolina 27412, United States ‡ Department of Chemistry, North Carolina Central University, Durham, North Carolina 27702, United States J. Chem. Educ. Downloaded from pubs.acs.org by KAOHSIUNG MEDICAL UNIV on 10/06/18. For personal use only.

S Supporting Information *

ABSTRACT: Mastery of core chemistry content is a degree requirement for several STEM majors. Gatekeeper courses, like general and physical chemistry, have a history of weeding out struggling students, and often underrepresented groups underperform. While gatekeeper courses ensure students are prepared for STEM degrees, it is essential they do not create undue obstacles or dampen interest in STEM. This article describes the implementation and evaluation of efforts to infuse polymer science into a two-semester sequence of general and physical chemistry courses. Survey and focus group data revealed positive feedback from students. Also, improved student mastery of polymer concepts and knowledge was demonstrated in preand postassessments. Ultimately, these initial efforts provided students with additional foundational skills and increased engagement with chemistry content. KEYWORDS: First-Year Undergraduate/General, Hands-On Learning/Manipulatives, Inquiry-Based/Discovery Learning, Polymer Chemistry, Polymerization

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from professors at NCCU, scores on students’ first chemistry exam often reveal their struggles with the content due to an insufficient amount of time studying or too much time spent on unproductive activities. Without aggressive interventions, students often fail to recover from receiving a low score on their first chemistry exam and end up receiving a grade of D or F, or withdrawing from the course altogether. Traditionally, the Department of Chemistry at NCCU has emphasized small molecule chemistry. However, there is educational literature emphasizing the importance of including polymer systems in chemistry curriculums6−11 and offering examples of how chemistry concepts can be tied with polymer science.10−13 The prevalence of polymers in everyday life14,15 with broad ranging areas of application can be integrated into chemistry curricula to remain relevant to students while maintaining the demands of the ACS regulated core content. Remaining relevant would not be such a hurdle if all chemistry lectures were viral hits. Unfortunately, the reality that confronts many chemistry instructors is challenging for two key reasons: (1) Students must receive a passing chemistry grade to continue their academic careers, yet they are often unengaged. (2) Students have accumulated inaccurate or incomplete knowledge over the years to bridge the abstract nature of chemistry models with their experienced macrolevel view of everyday life.16−18 Bridging the gap between the student’s experienced world and the abstract submicroscopic world of chemical models (such as atoms, electrons, intermolecular forces, etc.) is a challenge that is not adequately resolved using analogies, which can in themselves become a hindrance to

INTRODUCTION Colleges and universities play a pivotal role in increasing and diversifying the number of students obtaining Science Technology Engineering and Mathematics (STEM) degrees and entering the STEM workforce.1 It is necessary that all students in pursuit of a STEM degree have the minimum technical skillset and scientific grounding to succeed in their chosen fields. As such, students are often required to enroll in, and pass, entrance and exit gatekeeper courses like General and Physical Chemistry. Gatekeeper courses are used for and have a history of weeding out struggling students,2 thus thwarting students’ pursuits of a science career. Unfortunately, the literature suggests that these courses are often taught in isolated contexts without requisite skill or study support, limited instructor feedback, and few opportunities for formative assessments.3 Furthermore, underrepresented groups in STEM [women, minorities (African-American, Latino, and American Indian), and persons with disabilities4] tend to underperform in gatekeeper courses.5 While it is essential for gatekeeper courses to ensure that students are prepared and are able to enter and exit STEM degrees, it is also important that these classes are not creating undue obstacles for students, dampening their interests in STEM, and that all students, especially those underrepresented, have parity in access to resources, experiences, and accomplishments. At North Carolina Central University (NCCU), a Historically Black College and University (HBCU), chemistry is a core science. The American Chemical Society (ACS) has continuously accredited the department since 1974. Mastery of chemistry core content is a degree requirement for several STEM majors. Those who fail the two-semester General and Physical Chemistry sequence often change their majors. On the basis of anecdotal conversations and observations © XXXX American Chemical Society and Division of Chemical Education, Inc.

Received: April 19, 2018 Revised: September 23, 2018

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DOI: 10.1021/acs.jchemed.8b00288 J. Chem. Educ. XXXX, XXX, XXX−XXX

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The project consists of three major components: Polymer Ed, Polymer Train, and Polymer Research. Polymer Ed exposes students to polymer science content in laboratory modules through an adapted flipped classroom. The polymer-infused core chemistry content is delivered online in 10 min lecture videos enabling students to review material at their own pace. The lectures are supplemented with short readings and PowerPoint presentations. Students view the online content before class and complete online questions and problems. During class, students participate in group-based interactive learning activities that reinforce content from the online lecture. Table 1 depicts a comparison of traditional and polymerinfused classroom topics and laboratory activities. See Supporting Information for a syllabus example of General Chemistry II. Students enrolled in the polymer-infused general chemistry courses are also exposed to activities that support their success in the course. The activities are collectively called Polymer Train and focus on time management, math skills, study skills, scientific writing, and critical thinking skills needed for successful completion of general and physical chemistry. Lastly, students engage in Polymer Research through their minipolymer-project-based laboratories or as Research Fellows in faculty laboratories to further their understanding of chemistry and provide students with opportunities to work on research projects, present their work at conferences, coauthor manuscripts, and publish their findings in peer-reviewed journals.

understanding chemistry. What better way to enhance the appreciation of the relationship between structure and property from the molecular scale to the macroscopic scale than through the examples provided in discussions of polymers. The ACS Committee on Professional Training states in its guidelines for certified undergraduates that “the synthesis, analysis, and physical properties of small molecules give an incomplete picture of the higher order interactions that occur in macromolecular... systems, [therefore]... instruction must cover the preparation, characterization, and physical properties of such systems... [including] synthetic polymers.”19 Furthermore, there is a growing body of literature that explicates the benefits of including a research-based component to laboratory activities for undergraduate students for deeper learning and transformational STEM experiences.20−24 This recommendation from the ACS comes at a pivotal time for the Department of Chemistry at NCCU for two key reasons. First, the department is refocusing efforts to enhance teaching and research in materials science. One aspect of this endeavor is the development of an undergraduate curriculum in polymer chemistry. Polymer chemistry research is already becoming a productive mechanism for engagement within the department as evidenced the by successful solicitation for external funding and recent peer-reviewed publications. Second, the department has launched numerous approaches to support student success and increase retention and recruitment of majors. Together, this provided motivation for the current project, funded by the National Science Foundation’s HBCUUndergraduate Program Targeted Infusion Project (HBCU-UP TIP), to redesign introductory chemistry education at NCCU through the infusion of polymer science. The aim of NCCU’s HBCU-UP TIP project is to significantly change the delivery of core content to encourage better study habits, improve classroom performance, and intrinsically inspire undergraduates to engage in polymer research early in their academic careers with the intent to recruit more majors and improve retention and success of undergraduate students in chemistry. This article describes the implementation and evaluation of the first phase of a multipronged approach to infuse polymer science into the two-semester sequence of General and Physical Chemistry courses. We begin with an explanation of the multipronged approach and implementation. Then we discuss our methods for evaluating the project and conclude with results of efforts made thus far.

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ACTIVITIES For this article, the focus is on lab activities in Polymer Ed from general chemistry courses and Polymer Research, conducted in Physical Chemistry II. Laboratories

Four polymer-based laboratory modules were infused into the traditional laboratory techniques (Exp1: Naked Egg and Exp2: Exploring Polymers), density exploration (Exp3: Density of Polymers), and chemical reactions (Exp5: Addition and Condensation Reactions of Polymers) for General Chemistry I. In all cases, polymer laboratory topics in our General Chemistry courses were chosen for implementation by answering two questions: (1) What do the students already know? (2) What will happen if...? For example, density was introduced after activities that exposed students to household plastics and their respective recycling codes. Students were challenged to separate a mixture of four polymers in the form of small pellets (see Figure 1A). Mixtures were separated by taking advantage of differences in the properties of the substances that make up the mixture and the density of the solutions. In another intervention of polymer concepts, students prepared rigid polyurethane foam (see Figure 1B) and learned about the polymerization of monomer molecules as a preactivity to Reactions of Polymers (i.e., Exp5). Box 1 describes the implementation process for the density of polymer modules. An additional three polymer laboratories were infused into the traditional graphing (Exp1), soap (Exp3), and writing (Exp5) laboratories for General Chemistry II. Using the same two guiding implementation questions, students not only prepared soap but also were challenged to discuss large molecules, common household polymers, biological polymers, and the difference between these materials and soap. Pedagogical analysis of all the polymer-infused laboratories is provided in the Supporting Information.

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MULTIPRONGED APPROACH The goals of NCCU’s HBCU-UP TIP multipronged approach are to (1) improve student study habits, (2) enhance class performance, (3) encourage undergraduates to participate in polymer research, (4) recruit more students to STEM majors, and (5) increase retention and success of students in chemistry. The curriculum and educational activities are intended to foster an environment in which students achieve the above objectives through their courses, laboratory activities, and research experiences guided by faculty. Our vision is to teach the traditional course content highlighting polymer materials and properties (with minimum time devoted to polymer science) in order to engage students and thereby improve their overall performance and understanding in the course. B

DOI: 10.1021/acs.jchemed.8b00288 J. Chem. Educ. XXXX, XXX, XXX−XXX

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8

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Week

Traditional Classroom Content and Laboratory

[Matter and Energy]: Classes, atomic view, properties, and states of matter; Scientific method; Measurements, unit conversions, dimensional analysis No Lab [Atoms, Ions, and Molecules]: Nuclear model of atomic structure; Isotopes; Average atomic mass; The periodic table, naming compounds and writing formulas Lab1: Safety, laboratory rules, and techniques [Mass]: The mole; Writing balanced chemical equations Lab2: Density, accuracy, precision and graphing [Elemental Analysis]: Empirical and molecular formulas compared; Combustion analysis; Limiting reactants and percent yield [Quantum Model]: Light waves; Atomic spectra; Particles of light and quantum theory; Hydrogen spectrum; Electron waves; Quantum numbers; Pauli exclusion principle Lab3: Solid mixtures: Separating and isolating components [Quantum Model]: Sizes and shapes of atomic orbitals; Atom and ion electron configurations and sizes; Ionization energies; Electron affinities Lab4: Copper: Percent and formula weight in compound [Chemical Bonds]: Types of chemical bonds; Lewis structures; Resonance; Formal charge; Octet rule and exceptions; Bond lengths and strengths; Resonance; Electron configurations Lab5: Types of chemical reactions [Molecular Geometry]: The valence shell electron pair repulsion (VSEPR) model; Shape determines function: Molecular shape; Valence shell electron pair repulsion; Polar bonds and molecules; Description of multiple bonding; Dipole moment; Principles of molecular orbital theory Lab6: Acids and bases: Reactions and standardization [Stoichiometry]: Molar interpretation of a chemical equation; Amounts of substances in a chemical reaction; Limiting reactant; Theoretical and percentage yields Balanced chemical equations; Balancing simple oxidation−reduction equation; Molecular and ionic equations Fall Break (No Lab) [Reactions]: Precipitation reactions and rules; Decomposition; Combination; Combustion; Acid; Acid−base reactions; Oxidation−reduction Lab7: Titrating the acetic acid content in vinegar [Composition]: Molar concentration; Dilutions; Diluting solution; Gravimetric analysis; Volumetric analysis reactions Lab8: Studying Boyle’s law [Thermochemistry]: Basic concepts and definitions; Energy transfer; Enthalpy and enthalpy changes; Heating curves and heat capacity; Calorimetry/gas properties]: Measuring heat capacity and enthalpies of reaction; Hess’s law; Standard enthalpies of formation and reaction Lab9: Diffusion of gases and Graham’s law [Gases]: Gas pressure and its measurement; Empirical gas laws; Atmospheric pressure; The Gas Laws Lab10:9 Bottles: An adventure in chemical identification [Properties of Gases]: Gases in chemical reactions; Gas density; Daltons’ law and mixtures of gases; The kinetic molecular theory of gases; Real gases [Real Gases]: Kinetic; Molecular Speeds; Diffusion and Effusion

Polymer-Infused Classroom Content and Laboratory [Matter and Energy]: Classes, atomic view, properties, and states of matter; Scientific method; Measurements, unit conversions, dimensional analysis, Polymers in plant (polysaccharides) and animal (protein) life; Polymer names Lab1: Safety, lab orientation and naked egg [Atoms, Ions, and Molecules]: Nuclear model of atomic structure; Isotopes; Average atomic mass; The periodic table, naming compounds and writing formulas; Importance of carbon element in polymer design Lab2: Exploring commodity polymers and applications [Mass]: The mole; Writing balanced chemical equations Lab3: Density of various polymers [Elemental Analysis]: Empirical and molecular formulas compared; Combustion analysis; Limiting reactants and percent yield; Polymer MW; Empirical formula of polymers [Quantum Model]: Light waves; Atomic spectra; Particles of light and quantum theory; Hydrogen spectrum; Electron waves; Quantum numbers; Pauli exclusion principle Lab4: Solid mixtures: Separating and isolating components [Quantum Model]: Sizes and shapes of atomic orbitals; Atom and ion electron configurations and sizes; Ionization energies; Electron affinities Lab5: Copper: Percent and formula weight in compound [Chemical Bonds]: Types of chemical bonds; Lewis structures; Resonance; Formal charge; Octet rule and exceptions; Bond lengths and strengths; Resonance; Electron configurations; Polymer bonds, lengths, and strengths Lab5: Addition and condensation reactions of polymers [Molecular Geometry]: The valence shell electron pair repulsion (VSEPR) model; Molecular shape; Valence shell electron pair repulsion; Polar bonds and molecules; Description of multiple bonding; Dipole moment; Principles of molecular orbital theory; Polymer size and structure Lab6: Acids and bases: Reactions and standardization [Stoichiometry]: Molar interpretation of a chemical equation; Amounts of substances in a chemical reaction; Limiting reactant; Theoretical and percentage yields Balanced chemical equations; Balancing simple oxidation−reduction equation; Molecular and ionic equations; Polymer combustion reactions Fall Break (No Lab) [Reactions]: Precipitation reactions and rules; Decomposition; Combination; Combustion; Acid; Acid−base reactions; Oxidation−reduction Lab7: Titrating the acetic acid content in vinegar [Composition]: Molar concentration; Dilutions; Diluting solution; Gravimetric analysis; Volumetric analysis reactions; Polymer solution properties (i.e., solubility, form viscous solutions, etc.) Lab8: Studying Boyle’s law [Thermochemistry]: Basic concepts and definitions; Energy transfer; Enthalpy and enthalpy changes; Heating curves and heat capacity; Calorimetry/gas properties]: Measuring heat capacity and enthalpies of reaction; Hess’s law; Standard enthalpies of formation and reaction Lab9: Diffusion of gases and Graham’s law [Gases]: Gas pressure and its measurement; Empirical gas laws; Atmospheric pressure; The Gas Laws Lab10:9 Bottles: An adventure in chemical identification [Properties of Gases]: Gases in chemical reactions; Gas density; Daltons’ law and mixtures of gases; The kinetic molecular theory of gases; Real gases [Real Gases]: Kinetic molecular theory of an ideal gas; Molecular speeds; Diffusion and Effusion; Laws degassing polymer reactions

Table 1. Comparison of General Chemistry I Traditional and Polymer-Infused Content

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Box 2. Mini-Polymer-Research Project Learning Goals Students will explore light absorption, transmission, and scattering in order to understand the chemical microstructure, thermal and physical properties of polymers enabled by • Calculating the energy, velocity, wavelength, and wavenumbers of photons • Deriving operators and determine eigenvalues and eigenfunctions of operators • Manipulating wave functions involving 1−4 quantum numbers: normalize; calculate average, expectation, and most probable values; represent in Dirac notation • Solving the quantum mechanical particle-in-a-box, harmonic oscillator, and rigid rotor problems • Defining the wave functions for the hydrogen atom in various energetic states and use these wave functions to explain various properties • Relating NMR, FT-IR, and UV−vis information to atomic and molecular properties. • Deriving approximate wave functions for various multielectron systems and explain chemical bonds in simple homonuclear diatomic molecules • Utilizing perturbation theory to perform simple energy approximation calculations • Performing hands-on experiments in the lab that reinforce concepts learned in class

Figure 1. (A). Visual representation of density experiment with small pellets. (B) Students in general chemistry participating in foam polymer laboratory experiment.

Box 1. Pedagogy of Density Polymer Lab Expected Prior Knowledge • Familiarity with buoyancy of plastics in various liquids. • Understanding of the mass and volume of matter. Scientific Question • Can the relative density of an unknown plastic fragment be used to identify it in a mixture? Objective • Identify the 6 kinds of recycled plastic resins by measuring their density Student Outcomes • Define density and understand that it is a characteristic property of a substance • Identify plastics that float or sink in a solution of known density • Create tables to present results

The projects were designed to evaluate polymer materials relevant in state-of-the-art technologies such as drug delivery and water purification. The research questions, keywords, background information from at least two literature references, and the necessary polymers were provided to the students. Students were then expected to design 4 weeks of experiments that addressed the respective research questions using principles discussed in the physical chemistry lectures. Pedagogical analysis of projects selected by students is provided in the Supporting Information with one project showcased in Box 3. On the basis of their selected topics, students created a proposal outline, performed literature reviews, and proposed possible experiments for solving their research problem. Throughout, students submitted electronic writing assignments detailing their progress for instructor feedback to improve their projects.

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EVALUATION METHODS To evaluate the merit and effectiveness of components implemented from the multipronged approach, external evaluators utilized a values-engaged, educative (VEE) evaluation approach. The VEE approach, developed with NSF-EHR support, defines high-quality STEM educational programming as that which effectively incorporates cutting-edge scientific content, strong instructional pedagogy, and sensitivity to diversity and equity issues.26−28 The VEE evaluation approach encourages explicit attention to issues of diversity and equity, and responsiveness to the culture and context of the program. Additionally, this approach seeks to educate stakeholders about their program while also engaging the perspectives, concerns, and values of all legitimate stakeholders, including those traditionally silenced and underrepresented in the evaluation context. Outcomes associated with the infusion of polymer science through a multipronged approach were assessed using a mixed method research design. All research and evaluation activities were conducted with Institutional Review Board approval.

Mini-Polymer-Research Projects

Physical Chemistry II is an introductory level course to the quantum-chemical description of atoms, molecules, and solids and the fundamentals of molecular spectroscopies (UV−vis, IR, MW, Raman, NMR, EPR). Successful student outcomes are often hindered in this course due to the abstract nature of concepts, insufficient resources, and the lack of student motivation in the physical chemistry course.25 In Physical Chemistry II, students completed mini-polymer-research projects over the course of 4 weeks, concluding with a final presentation and report. The objective was to apply concepts and techniques of quantum theory to systems for students to better understand fundamentals through hands-on-exploratory activities with polymers. Box 2 outlines the learning goals of the research projects as they pertain to the concepts explored in Physical Chemistry II. D

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focus groups was selectively transcribed and themed for analysis. Students in the physical chemistry course also rated their perceived technical and soft skills related to polymer chemistry prior to and after the mini-polymer-research projects. Ratings ranged from 1 (very weak knowledge) to 5 (very strong knowledge) on a Likert-type scale. The detailed list of rated skills can be found in the Supporting Information.

Box 3. Example Pedagogical Rationale of a Student MiniPolymer-Research Project Project Title: Guest−Host Interactions Enabled by Hyperbranched Polyglycerol Hydrogels Rationale: Hyperbranched polyglycerols (HPG) are unique materials extensively investigated for their desirable properties: abundance of terminal functional groups, dendritic-like properties, and biocompatibility. The abundance of terminal hydroxyl group can be modified to create chemically crosslinked pores. Objective: Evaluate provided cross-linked HPG samples for their ability to capture various guest dye molecules and release the molecules over time. Student Outcomes • Solve the quantum mechanical particle-in-a-box model to obtain theoretical values for dye absorptivity • Calculate the energy, velocity, wavelength, and wavenumbers of photons associated with the absorptivity of each dye • Develop a six-point calibration curve for each dye using UV−vis • Measure the amount of dye released over time using a predetermined UV−vis generated calibration curve Physical Chemistry Connection • Calculate the energy, velocity, wavelength, and wavenumbers of photons • Solve the quantum mechanical particle-in-a-box

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EVALUATION FINDINGS

Polymer Ed

Following the density and plastics polymer-infused laboratory modules, surveys were conducted using a five-point Likert-type scale from “Strongly Disagree” to “Strongly Agree”, “Not at all Effective” to “Very Effective”, and “Not at all Useful” to “Very Useful”. Tables 2−5 show the Likert-type rating means for Table 2. General Chemistry I Polymer-Infused Lab Survey Statement Results Mean Scoresa by Module (N = 17) Survey Statements for Response

Density Plastics

Topics covered stimulated my interest Lab improved my knowledge and understanding of topics Resources given were valuable to me Lab was well organized Lab fulfilled my expectations Enjoyment of lab module format

3.59 4.24 4.00 4.06 3.88 4.00

4.00 4.18 3.94 4.12 3.94 4.00

a

Likert-type rating as follows: strongly disagree = 1; disagree = 2; neutral = 3; agree = 4; strongly agree = 5.

The data collection methods included two pre- and postknowledge assessments, external evaluator observation of laboratories, general chemistry satisfaction surveys, student focus groups, and perceived change in research skills self-rating by physical chemistry students. Students in General Chemistry I and II laboratory courses completed pre- and postknowledge assessments at the beginning and end of each polymer-infused laboratory module. Typically, the assessments consisted of 10 multiple choice and/or short answer questions. Laboratory instructors created all assessments. Evaluators used t-tests to determine statistical significance in a mastery of concepts from pre- to postassessments. SPSS removed any missing cases. A sample pre- to postassessment can be found in the Supporting Information. General chemistry students also completed surveys after each polymer experiment. Questions probed students’ learning of concepts, the practicality of content, and interest in subject matter. Survey results were analyzed using descriptive statistics. Responses were confidential to maximize the truthfulness of opinions. The full survey can be found in the Supporting Information. Two 30 min semistructured focus groups were conducted with students in the physical chemistry course to understand their experiences while conducting mini-polymer-research. Attention was given to their goals for the project, skills developed, and future aspirations in STEM fields. The focus groups were held at the beginning and end of the semester with four students. The first was via video conference and the second face-to-face. A protocol was developed for both focus groups and followed to guarantee appropriate topics were covered. To get the most out of student responses, students were informed that personal identifiers associated with their comments would be removed prior to reporting the findings. Dialogue from the

Table 3. General Chemistry I Polymer-Infused Lab Survey Statement Utility Results Mean Scoresa by Module (N = 17) Survey Statement for Response

Density

Plastics

Extent concepts presented were useful to you

3.59

4.35

a

Likert-type rating as follows: not at all useful = 1; somewhat useful = 2; neutral = 3; useful = 4; very useful = 5.

Table 4. General Chemistry II Polymer-Infused Lab Survey Statement Results Mean Scoresa by Module (N = 19) Survey Statements for Response Topics covered stimulated my interest Lab improved my knowledge and understanding of topics Resources given were valuable to me Lab was well organized Lab fulfilled my expectations Enjoyment of lab module format

Diapers, Gel, and Slime

Surface Tension

Solubility

4.00

3.63

3.68

3.21

3.42

3.68

3.74 3.42 4.05 3.84

3.89 3.37 3.84 3.58

3.84 3.42 3.95 4.05

a

Likert-type rating as follows: strongly disagree = 1; disagree = 2; neutral = 3; agree = 4; strongly agree = 5.

each question. Overall, the polymer-infused lab modules were well received by students. In General Chemistry I, both the density and plastics laboratory experiments were highly rated on improving knowledge and understanding of topics. Students E

DOI: 10.1021/acs.jchemed.8b00288 J. Chem. Educ. XXXX, XXX, XXX−XXX

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Table 5. General Chemistry II Polymer-Infused Lab Survey Statement Utility Results

Table 8. Survey Results of Participant Self-Rating of Skills

Mean Scoresa by Module (N = 19) Survey Statement for Response

Diapers, Gel, and Slime

Surface Tension

Solubility

Extent concepts presented were useful to you

3.68

3.89

4.39

Skills

Pretest Mean, N=5

Post-Test Mean, N=4

Difference

4.00 4.00 4.20 4.20

4.50 4.25 3.50 4.50

0.50 0.25 −0.70 0.30

3.40

4.25

0.85

3.40

4.00

0.60

3.00 2.60

4.00 3.75

1.00 1.15

3.00

3.75

0.75

3.00

3.75

0.75

3.80

4.00

0.20

Calculate the energy of photons Calculate the velocity of photons Calculate the wavelength of photons Calculate the wavenumbers of photons Solve the quantum mechanical particle-in-box problems Solve the harmonic oscillator problems Solve the rigid rotor problems Relate NMR to atomic and molecular properties Relate FT-IR information to atomic and molecular properties Relate UV−vis information to atomic and molecular properties Perform hands-on experiences in lab that reinforce concepts learned in class

a

Likert-type rating as follows: not at all useful = 1; somewhat useful = 2; neutral = 3; useful = 4; very useful = 5.

also noted agreement on “Enjoyment of lab module format” for each topic. In Table 3, participants indicated high usefulness for “Extent concepts presented were useful to you” (4.35) with the plastics experiment. In General Chemistry II, the diapers, gel, and slime polymer lab module was highly rated on “Topic covered stimulated my interest” (4.00) and “Lab fulfilled my expectations” (4.05). In Table 5, students also indicated the solubility polymer lab module as most useful to them (4.39). Students also completed pre- and postknowledge assessments for the density and reaction of polymer-infused lab modules to measure their understanding of scientific content. According to Table 6, statistically significant improvement was found in student mastery of knowledge for each concept. The reaction of polymers experiment had the greatest improvement of 1.91 points. Table 7 provides t-Test results for General Chemistry II. There was statistically significant improvement in student mastery of surface tension from 4.12 to 6.46, an improvement of 2.34 points (t12 = −3.586, p < 0.05). The same trend was evident for the solubility and diapers, gel, and slime

were unable to remove the dropped student from the prerating sample. During the second focus group, students indicated the minipolymer-research project was their first opportunity to complete independent research not often found in traditional science courses. One student described the experience as “I worked more independently during this experiment than ever before... that was a good experience.” When describing how the research project affected them as a researcher, one student commented, “it has affected me in a good way, wanting to know more... want to do more hands-on experiments so I can get a better understanding.” Students indicated their experiences as a researcher improved because of the tasks performed in the course. Ultimately, working independently and conducting research were the most important skills developed for their future STEM career aspirations.

Polymer Research

Overall, students indicated having a better understanding of research and technical skills required to apply concepts and techniques of quantum theory to systems. Table 8 shows the average participant self-rating of skills. Specifically, regarding technical skills, the majority of students’ self-ratings increased between pre- and postsurvey. “Relate NMR to atomic and molecular properties” had the greatest increase (1.15) between ratings. “Calculate the wavelength of photons” declined from pre- to postassessment. Evaluators suspect the reason for a decrease in self-rating skills was a student’s withdrawal from the course. Surveys were completed anonymously, so evaluators

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LIMITATIONS AND FUTURE RESEARCH We acknowledge that the data given does not fully capture the implementation of all project components of the multipronged approach for students in the two-sequence General and Physical Chemistry gatekeeper courses. Future research should

Table 6. Comparison of t-Test Results and Descriptive Statistics Results for Polymer-Infused Pre- and Post-Test General Chemistry I Assessments Pretest

Post-Test

Assessments

Mean

SD

Mean

SD

95% CI for Mean Differencea

t

df

Density of Polymer (N = 20) Reaction of Polymers (N = 13)

5.53 4.62

1.89 1.66

6.30 6.53

1.33 1.39

−1.36, −0.19 −2.83, −1.02

−2.794 −4.629

19 12

a

p < 0.05; missing cases were removed.

Table 7. Comparison of t-Test Results and Descriptive Statistics Results for Polymer-Infused Pre- and Post-Test General Chemistry II Assessments Pretest, N = 22

Post-Test, N = 22

Assessments

Mean

SD

Mean

SD

95% CI for Mean Differencea

t

df

Diapers, Gel, and Slime Surface Tension Solubility

2.09 4.12 1.85

1.18 3.36 1.17

2.50 6.46 2.72

0.96 3.64 1.16

−1.95, −0.96 −3.63, −0.96 −1.38, −0.34

−6.137 −3.586 −3.457

21 21 21

a

p < 0.05. F

DOI: 10.1021/acs.jchemed.8b00288 J. Chem. Educ. XXXX, XXX, XXX−XXX

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Notes

consist of more observational and assessment data of students for each component of the approach: for instance, collecting comparison data on students enrolled in the polymer infusion sections with the eight-week Polymer Train versus the traditional structure of general and physical chemistry, along with tracking retention in STEM majors at NCCU and students seeking a graduate degree. As a result, researchers can examine the long-term influence(s) of polymer infusion in gatekeeper courses and students’ pursuing opportunities for further development of their scientific inquiry skills, particularly minority students who are disproportionately underrepresented in STEM fields.

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work is supported by the National Science Foundation’s Directorate for Education and Human Resources through the Historical Black Colleges and Universities Undergraduate Program Target Infusion Project, Award 1623056.

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CONCLUSION In this article, we have provided details of the approach, implementation, and evaluation of outcomes on student learning in General Chemistry and Physical Chemistry laboratories infused with polymer-based activities. Participating students have responded positively to the interventions based on assessments, surveys, and focus group data. Students indicated improved knowledge of concepts following polymer laboratories and gaining valuable research skills for their future. Furthermore, incorporation of polymer interventions to enhance real world application of science content, hands-on laboratory experiences, and independent research projects discussed in this project aided students in successfully engaging with chemistry content. The overall impact of these polymer-infused initiatives provided students with a deeper level of understanding of the theoretical and practical foundational footing needed for a transformative experience in their STEM coursework, along with students expressing increased interest in STEM, thereby possibly providing more diverse representation in the STEM workforce or graduate degree programs. The numbers of articles that focus on chemistry curriculum changes suggest that NCCU is not the only university confronting a need to revamp chemistry curriculum. While HBCUs play a major role in producing underrepresented minority STEM graduates29,30 and the project described was implemented at NCCU, we believe all of the activities are broadly applicable to any chemistry program seeking to engage students, particularly underrepresented STEM students.

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ASSOCIATED CONTENT

* Supporting Information S

The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.8b00288.

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REFERENCES

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General Chemistry II table of traditional and polymerinfused course syllabus calendar, pedagogical analysis of polymer-infused laboratories, Physical Chemistry minipolymer-project pedagogical analysis, student satisfaction survey for polymer laboratory experiments, rating list of students perceived skills, General Chemistry II course syllabus, and example pre- and postassessment (PDF, DOCX)

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*E-mail: [email protected]. ORCID

Cherie M. Avent: 0000-0001-9855-5239 G

DOI: 10.1021/acs.jchemed.8b00288 J. Chem. Educ. XXXX, XXX, XXX−XXX

Journal of Chemical Education

Article

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DOI: 10.1021/acs.jchemed.8b00288 J. Chem. Educ. XXXX, XXX, XXX−XXX