Chapter 26 Writing a Scientific Paper Chemicals

Types of Scientific Papers

There are commonly three types of scientific reports that researchers may encounter in work. They are Review, Original Paper including full paper, communication (equivalent to Letters in some journals) to editor, and Patent. In writing, they are different, but more or less, they have similar constituents, i. e. Title, List of authors’ names, Facilities, Abstract, Keywords, Introduction, Methods, Results and Discussion, Conclusion, References, and Acknowledgments if required. Here, we give some proposals on how to write a manuscript of full original research paper, which may be the first and most frequently applied form for a student. After all, it is the age of Internet. Sufficiently taking the advantages of Internet is always recommended. What we can do in this unit are, at first, to save the readers time, and at second, which is the most important, to give some proposals according to our experience in revising the students’ manuscripts and dissertations of academic degrees.

Compiling a Manuscript in Faith

Students, especially doctoral candidates are normally required to work with a project having a definitive target. They work hard and do a lot of experiments, but it is often that two years have passed, whereas the target is still far away. At the moment, some may begin to worry about the dissertation in due time. Therefore, according to our experience, we have a proposal: cherish the faith, “No Useless Data.” First, review all the experiments you have done and convert all the raw data into tables and/or figures. Second, consider what the tables/figures say and then extract a topic from these data, for example, “Synthesis of. . . ,”“Effects of . . . on “Improvement of. . . ,”“Characterization of . . . by. . . ,” etc. Third, have a search with keywords including this topic on Internet, for example, Sci Finder, ISI Web of Knowledge, Scopus, etc.Skim through all the references to check the originality of the topic. If it is original, you have a paper; otherwise, repeat the above steps. By this means, you may possibly refresh your mind. Remember that the final title of dissertation is frequently determined by the papers published, rather the original project.

On the other hand, manuscript, as it is called, is different from the regular form of paper as you have read in the scientific journals. It is written for the editor and referees who judge your research report whether publishable or not in a specific journal. This is the point. For you, you have to highlight the novelty of your results significantly enough to grasp the sights of editor and referees, representative of the readers’ interests. For the publisher, the manuscript format is designed for the convenience of editor and referees’ judgments. This is the basic principle we have to adhere to. Therefore, sometimes, for the conciseness, you have to sacrifice some noble data in the formal paper, instead attaching it as a supplementary document.

Attention to the Details and Style

Use present tense throughout the manuscript to report background information that is already established. For example, “Although these examples represent significant advances toward entirely aqueous systems, the catalysts (and often the monomers) are insoluble in water, and the polymerization reactions take place in the organic phase. ” Future tense is used for work that will be done. For example, “We will (are currently) investigate (-ing) the factors governing peak broadening in these systems. ” Past tense is always used to describe results of experiment. For example,“After 15 min at 45℃, the reaction was > 95% complete and the relative integration of the alkylidene protons of the two propagating species (coalesced as a broad singlet at 19. 2 ppm) did not decrease either during the reaction or after all monomer had been consumed. ”

Nowadays, most manuscripts are written and post-treated on personal computers and Internet. Therefore, it is convenient to take advantage of Internet resources, for example, to download a template from the website of the publisher or a specific journal (Information for Authors) where the manuscript is going to be submitted. The template contains all the information of writing infrastructure such as the word styles and size, the line spacing, and marginal spaces.

TITLE

The title should accurately, clearly, and concisely reflect the emphasis and content of the paper. The title must be brief and grammatically correct.

AUTHOR NAMES

Include all those who have made substantial contributions to the work, even if the paper was actually written by only one person. Use first names, initials, and surnames (e. g. , John R. Smith, Thomas Wang, Linda Zhang).

AUTHOR ADDRESS

The affiliation should be the institution where the work was conducted.

ABSTRACT

The abstract should briefly state the problem or purpose of the research, indicate the theoretical or experimental plan used, summarize the principal findings, and point out major conclusions. The optimal length is one paragraph.

MANUSCRIPT TEXT For full guidelines, please see the Guide, Notes, Notice, or Instructions for Authors that appear in each publication’s first issue of the year and on the World Wide Web at http://pubs. acs. org. This may include an introduction, experimental details (sections titled Experimental Methods, Experimental Section, or Materials and Methods), theoretical basis (sections titled Theoretical Basis or Theoretical Calculations), results, discussion, and conclusions.

The template is interactive and deliberately designed for manuscript typing. With this template, the author is just required to insert his own content according to the instruction, and then delete the instructive words. For brevity, we recommend the readers to read this template. Hereafter, we will give some recommendations, which are not included in the template but helpful according to our experience.

Captioning in the Manuscript Text

Captioning is a frequently used method for separating the body of text into sections, especially for a long paper concerning with many experiments or theoretical aspects. Headings show how each section of information is laid out and organized. Capital letters, underlining, point size, and position on the page help differentiate rank or level, for instance, “1. Effects of Lewis acids”, “1. 1. Concentrations of Lewis acids”, “1. 2. Temperature of reactions” and so on.

Abstract

The Abstract summarizes your study, but often emphasizes results and conclusions. It usually starts from a very brief question asked (the goal of the study), the experimental design, and then the main observations, and finally main conclusions. It should be pointed out that the “question asked” does not mean you must type a sentence ending with a question mark. For example, “To realize the high conductivity of gel, we. . . ” or “The monodispersed hydrogel microspheres with novel p H-transition were prepared. ” These are all “questions”, connoting a question of “Is it possible?”; of course, the latter is main conclusion too. Here, we must stress that conclusions are objectively drawn from the results, neither the Chinese-styled connotation nor the potential applications of observations. For example, “These results indicated that the mini monomer droplets were the main loci of particle formation. ” Analogous to the sentences in the manuscript drafts of students we often revise, such sentences are not conclusions, as “Success of living ring-open metathesis polymerization in aqueous phase created a new era in the study of polymerization.” or “It was environmental friendly, thus a potential and prospective method in the applications of biomedical synthesis. ”

Moreover, an abstract should be very succinct-it should be a single paragraph and in most journals the number of words is limited (for example, in less than 300 words). However, it should stand on its own without referring to any other part of report such as a figure or table, neither to works of others. Therefore, the number of cited references such as “[1]” and figure/table number like “Fig. 2” do not appear in the Abstract. Abstract is written in past tense for summarizing the work you have done. At last, the full names of substances and equipments should be given, followed by their abbreviations in parenthesis if needed, unless they are everyone-knows, for example, HC1, Na OH, K" (even though, giving their full names is better).

ABSTRACT: The characteristics of reactions in the monomer phase, aqueous phase, and the interface of monomer/aaueous phase of soap-free emulsion polymerization of 4-vinvlpyridine (4VP) and styrene (St) system were evaluated by using the different types of initiators, addition of organic solvents, and changes of agitation rate. The oil-soluble initiators, 2'-azobis(2,4-dimethylvaleronitrile) (ADVN),benzoyl peroxide (BPO), and 2,2'-azobis(isobutyronitrile) (AIBN), the organic water-soluble initiator, 2,2'-azobis (2-amidinopropane) dihydrochloride (V50), and the inorganic water-soluble initiator, potassium persulfate (KPS), were used. 'H NMR and scanning electronic microscopy (SEM) were employed for the characterizations. As a result, the mechanism of interfacial particle formation was supported. Namely, the minimonomer droplets were generated by the disturbance in the interface of monomer/aqueous phase due to the agitation. The minimonomer droplets were stabilized by the adsorption of surface-active oligomer generated by the reactions in both the aqueous phase and the interface. The monomer transfer from the bulk monomer phase to the growing particles was via the coalescence of minimonomer droplets with particles. The role of reaction in the aqueous phase was proposed to just provide the surface-active oligomer for the stabilization of particles. The rapid reaction in the aqueous phase due to the high concentration of hydrophilic monomer produced longer hydrophilic chains and led to the coagulation of particles by a bridging-coagulation effect. On the basis of this mechanism, the coagulum-free stable latices with high monomer conversion were prepared bv using KPS and AIBN and, theoretically, can be prepared bv using any type of initiators at a high level of solid content and feed ratio of hydrophilic monomer.

Keywords

Keywords are selected for the potential searchers who are interested in your topic. Hence, the proper selection of keywords is helpful to improve the cited number of your paper. Keywords usually consist of no more than five words or phrases. As an empirical rule, they are names of specific substance/method, topic, and field of research, for example, 4-vinylpyridine, styrene, mechanism of particle formation, soap-free emulsion polymerization.

Introduction

Globally, the introduction should be brief, but do indicate clearly the objectives or purposes of the research, either experimental or theoretical analysis, performed, as well as current appropriate background. Please remember that the target of introduction is to let the reader know enough to appreciate the relevance of the work and why it is appropriate to ask the question that you will address with your study.Always state the hypothesis and/or objectives in your introduction. For illustrative purpose. The first sentence in each of the two paragraphs underlined provides the backgrounds of this research, but the macroscopic or very early background information is given in the first paragraph and the concrete information tightly connected with the topic of this paper in the second. The sentences beginning with“Although these examples represent significant advances . . . ” and “Although these complexes serve as robust polymerization catalysts . . . ” show the problems or shortcomings of the existing methods, while the subsequent sentences remark the necessities to solve the problems and countermeasures that the author considered. The last two sentences declare what the author has done and will do. Such a writing strategy is very commonly adopted in scientific papers. Of course, this paper is a short Communication. The description is very succinct. For a full paper, they may be expanded appropriately by giving more details. In this regard, outstanding abilities of comprehension relying on widely read references is treasure, and also for the discussion. Anyway, free writing is always recommended, but the scientific logics are always the life of a scientific paper.

The development of functional group tolerant, late transition metal polymerization

catalysts has recently enabled living ring opening metathesis polymerization (ROMP). la-cfree-radical polvmerization. ldand polymerization of isocyanidesle in wet organic media. Although these examples represent significant advances toward entirely aqueous systems, the catalysts (and often the monomers ) are insoluble in water ,and the polymerization reactions take place in the organic phase. The development of water-soluble catalysts that will polymerize monomers in a living fashion2 in entirely aqueous solution has remained a principal synthetic goal, particularly in light of emerging biomedical applications for water-soluble polymers which demand precise control over polymer length and polydispersity. 3 We report the first example of a living polymerization taking place in entirely aqueous solution, in the absence of surfactants or organic solvents, using ROMP initiated by water-soluble ruthenium alkylidene complexes.

The aqueous ROMP of strained, cyclic olefins initiated by group VIII salts and coordination complexes is well-documented,4 Although these complexes serve as robust polymerization catalysts in water, the polymerizations are not living and inefficient initiation steps produce erratic results ( typically less than 1% of metal centers are converted to catalytically active species) Recently, we reported water-soluble ruthenium complexes 1 and 2, containing preformed alkylidene fragments that initiate rapidly and quantitatively. 5 This dramatic increase in initiation efficiency prompted us to investigate the potential for these alkylidenes to initiate living polymerizations in entirely aqueous solution.

Methods

All methods and materials performed in the study must be documented. Completely copying the methods from other works, under any circumstances, should be avoided. Summarizing in your own words is always recommended. Of course, sometimes, the phrases such as “described elsewhere [ref]” are nice choice. Even though, please note that the small details and the common knowledge in the research field are not welcome if they are not particularly important in the experiments. For example, “I dropwise added l0 m L Na OH (IN) solution with a glass pipet into a 100-m L beaker containing 20-m L Ca Cl2(10wt%) solution. The white precipitate was produced. I filtered out the white precipitate by using a filter paper and a glass filter funnel. ” If the “dropwise addition” is not particularly important, these sentences can be shortened to “The precipitate was prepared by adding 10 m L Na OH (IN) into 20 ml Ca Cl2(10wt%) solution. ” The filtration separating the solid from solution is the common knowledge in chemistry and can be omitted. In addition, in this latter sentence passive voice was used to describe the experimental procedure, a standard for reporting the method in most scientific publications.

To give another example, one would write “The living ring-open metathesis polymerization was conducted at 45℃. ” instead of “We conducted the living ring-open metathesis polymerization at 45℃. ”

Although it might be easy to narrate the experimental procedures in chronological order, the general and effective fashion is to state the method details under headings devoted to specific procedures or groups of procedures.

Experimental Section

All reagents should >- be given including water

- For conciseness

Materials. Monomers 4-vinylpyridine (4VP) and styrene (St) and solvent ethyl acetate (EA) and toluene were purchased from Kishida Chemical Industries Co. Ltd. Water-soluble initiators, 2,2’-azobis(2-amidinopropane) dihydrochloride (V50) and potassium peroxide (KPS), oil-soluble initiators benzoyl peroxide (BPO), 2,2’-azobis (isobutyronitrile) (AIBN), and 2,2’-azobis (2,4- dimethylvaleronitrile) (ADVN) were offered by Wako Chemical Industry Co. Ltd. Ethyl acetate (EA) and toluene were distilled under the atmospheric pressure. Other reagents were distilled under reduced pressure except for the initiators, which were used without further purification.

The distilled and deionized (DPI) water with the conductivity of 18 MQ cm’1 by employing a Milli-Q water purification system (Millipore) was used.

Methods of Experiments. A standard recipe for polymerization is shown in Table 1. The p H 2 was the consequence of using the initiator, V50, as reported in the previous papers. 8’10 It was calculated from the amount of HC1 attached on V50. Therefore, for better comparison, the p H of water was adjusted to 2 when using the oil-soluble initiators.

Both the batch and semibath emulsion polymerization were employed and performed in a 300 m L four-neck, round-bottom reactor equipped with an anchor-type agitator (adjusted at the height of 10 mm from the bottom of the vessel), a condenser, a nitrogen inlet, and a rubber stopper for sampling. Nitrogen was bubbled through the mixture of reagents for 1 h before elevating the temperature, and the nitrogen blanket was maintained throughout the polymerization. For the batch polymerization, while KPS was used as initiator, the KPS solution free of oxygen by bubbling nitrogen for 1 h was added when the temperature of reaction mixture attained 70 ℃. However, while using oil-soluble initiators, the initiators first was dissolved in the monomer and then added the monomer into the water free of oxygen (70℃). For the semibatch polymerization, the monomer containing initiator was equally divided into three parts (10 g/part). Each part was added dropwise into the reactor (70℃) within 2 h. The three parts were continuously added without any time intervals.

a Variable (0-10) for measuring the partition of comonomer. The amount of water changed simultaneously. b Based on the amount of monomer.

The monomer conversion was measured by gravimetry. The latex (ca. 2 m L) was precipitated with 0. 5 N KOH solution containing 0. 01 wt % hydroquinone (HQ) and then dried by vacuum after repeating twice the cycle of centrifugation-hot water washing.

- For conciseness

Characterization. The partition of monomer and solvent was determined by ‘H NMR (ALPHA-500, JEOL) operated at 500 MHz, 30℃, for which the details were shown in the. Appendix of the previous paper. 8 The p H of water was adjusted by adding KOH or HC1 and measured with a p H/ion meter (HORIBA F-23, Horiba Ltd. Co. , Tokyo, Japan). The solid content of latex was determined by gravimetry.

The size and shape of dried microspheres were observed by scanning electron microscopy (SEM) (JEOL JSM-5310). The SEM sample was prepared as follows: one drop of dilute latex (1x10 g/m L) was cast on a stage covered with an aluminum film; after being dried at room temperature, it was coated with a thin gold film.

All of the experient were reproducible

Experimental Section is divided into three sub-sections, namely materials, experimental operations, and characterization operations. In the section of Materials, the full names and abbreviations of chemicals, the providers’ names and treating methods are given, whilst in Methods of Experiments, the recipes are presented and the concrete operations of the reactions are described in detail. In Characterization, the equipments (name, type, and provider) and the operation methods including the post-treatment of samples and raw data are described.

At last, the information that would be irrelevant to an independent investigator should not be included. For example, not everyone uses the same computer software, for instance, MS Word and Excel. The programs used to organize or plot data are not important if they are not particularly important to the results. However, it should be noticed that, if you used special software to plot diagrams/figures, you had better transform the figures into a universal data format, for example, JPG, TIF, etc:, otherwise, the figures might not be opened on the referees’ computers.

Results

Raw data include all observations or data obtained from experiments. Raw data should not be listed in a paper unless they are needed to show evidence for specific conclusions which cannot be obtained by looking at an analysis or summation of data. Therefore, it is essential to analyze the original data, and then present them in the form of figures (graphs), tables, and/or descriptions of observations. The converted data are therefore just figures, which are better than tables, and the latter are preferable to straight text. We suggest, before starting to write, please consider what the topic of paper is and then align the tables/figures logically. For example, the topic is “success of polymerization in aqueous phase”. Around this topic, the catalyst structure should be given at first. Subsequently, provide the principle of the reactions, the recipe formulated in this paper, before the conversion of monomers. Hereto, these just prove the occurrence of reaction. The next data must be the molecular weight verifying the production of polymer. This is the stem logic. Hereafter, the data of polydispersity of molecular weight, the structure of polymer and polymerization rate, etc. , are optional, which may be either added as the enhanced evidence or used in another topic such as “Effects of concentration of Brensted acids on the polydispersity of molecular weight. ” Briefly saying, put in the data that are absolutely needed.

In addition, to give the results enough clarity and continuity in the context, the relationship between the converted data and the specific outcome or overall study should be described. For example, rather than just putting a table/figure in the paper and going on to the discussion section, write something like “To probe the living nature of the aqueous polymerizations conducted in the presence of acid, an NMR-scale polymerization of monomer 3 was conducted employing DC1 (1. 0 equiv relative to alkylidene), and the relative amount of propagating species was quantified by integration of the alkylidene protons against the aromatic protons of the polymer end groups. ” The results are shown in Fig 1. “After 15 min at 45 “C, the reaction was > 95 % complete and the relative integration of the alkylidene protons of the two propagating species (coalesced as a broad singlet at 19. 2 ppm) did not decrease either during the reaction or after all monomer had been consumed. ” The same goes for tables.

The table or figure should be presented with a title, explaining what the table or figure is showing. The details about it can be found in the template. Here as a reminder to the readers, please insert the number of tables/figures in text body of manuscript where they are expected to be put in. For example, open a new line at the head of paragraph, write “***Figure 1, Table 2***”. It means that they should be put at the appropriate places in the followed paragraph(s).

Discussions

It is very popular that the discussion directly follows the interpretation of data. Discussion is the most important part in a scientific paper. In this part, the author has to make a decision, if the experimental results support/reject a hypothesis, or postulate his/her own hypothesis with confidence. The first sentence underlined in black (“Many authors have reported the use of oil-soluble. . . ”) starts reviewing previous works tightly correlated with this study. Notice the two sentences in this paragraph beginning with “However”. The first “However” macroscopically points out that fewer previous works cover the study in this paper. The “but” sentence gives a particular example. The second “However” shows the inadequate consideration in previous studies. All these sentences serve the purpose of author’s discussion about the new data and the reasons for the hypothesis. The last sentence in the second paragraph is a new explanation.

Many authors have reported the use of oil-soluble initiators in the emulsion polymerization. 2,28,29 recently in the miniemulsion polymerization systems in particular. 30 32 However, most of them focused on the emulsion polymerization systems in the presence of emulsifier and rarely on the soap-free emulsion polymerization system.

The probable reason was that the polymerization in the monomer phase was inevitable, which consequently led to the formation of coagulum based on the conventional mechanisms of emulsion polymerization. For example, Kim et al. 33 reported that the amount of coagulum was 39% and 43% in the batch soap-free emulsion polymerization of styrene with a small amount of Na SS, while using AIBN and BPO, respectively. Torii et al. 34 investigated the effects of water-soluble, nonionic azo-initiators on the emulsion polymerization (VA-080, 082, 086, 088). They found that these initiators could not be used for the soap-free emulsion polymerization of styrene, but the latex could be prepared without coagulation by adding 30% acrylamide (AAm). The generation of coagulum in the batch soap-free emulsion polymerization of St/AAm (7/3 w/w) was not correlated to the solubility of initiator in water but to the stabilizing ability of fragments derived from the decomposition of initiators, the decomposition rate, and the efficiency of initiators. However, the partition of initiator in the different phases of the polymerization system was not discussed.

In our views. ADVN should be more hydrophobic than AIBN according to their chemical structures. Therefore, compared with AIBN, ADVN is more difficult to enter the polar interface. Moreover, the kd of ADVN is much higher (kd(70℃), ADVN in toluene, 1. 9×10-4s-1; AIBN in styrene, 4. 72×l0-5s-1; h (74. 8℃), BPO in styrene, 1. 83×l0-5s-1). 26These two factors determined that the bulk polymerization rate is much higher than that in the interface, as shown in Table 2, which led to much more amount of coagulum in the batch emulsion polymerization. This explanation seemed to be also applicable for the results obtained by Ohtsuka et al. For example, the kd ‘s of initiators are VA-080 > 082 > 086 > 088, but the polarity is VA-080 < 082 < 086< 088. The kdof AIBN is a little larger than that of BPO, but the solubility in water shows that AIBN is much more polar, and therefore the concentration of AIBN in the interface is higher than that of BPO. This is the reason that the solid content of latex obtained by using AIBN was higher than that by using BPO.

Basically speaking, comparisons with previous data and explanations of the new data are the main task in the discussion section. For showing the objective of your discussion, any conclusive sentences appearing in the text should be either noted by citing the reference or regarded as author’s own conclusion. If neither, please do not put them in. For example, in “The reasons for this broadening are unclear at this point, although in aqueous GPC artificial peak broadening may occur due to ionic interactions between charged polymers and charged species on the gel phase”, the conclusive sentence in bold black is a cited result from ref. 12. In addition, do not simply dismiss a study or part of a study as “inconclusive”. Suggest how the experiment could be modified based on the conclusions you have in order to properly test the hypothesis. At this moment, some adverbs indicating uncertainty are helpful to avoid the referees’ serious criticism, such as “might”, “could”, “possibly”, etc. , and some phrases “we think/consider”, “look like or seem”. For example,“Additionally, the equilibrium between the bisphosphine propagating species and the monophosphine propagating species could be responsible for the observed broadening, as the monophosphine species is a more active polymerization catalyst (see below). 13 We are currently investigating the factors governing peak broadening in these systems. ”

Refer to work done by specific individuals (including author himself/herself) in past tense. Refer to generally accepted facts and principles in present tense. For example, “Monomer 4 was rapidly and completely consumed, and the concentration of the propagating species remained constant both during and after the polymerization of the second block. Within the limits of NMR sensitivity, the direct observation and quantification of the propagating alkylidenes in the above experiments demonstrates the absence of chain termination in these reactions. ”

Conclusion

Concluding remarks are a summary of all conclusions produced in the discussion over the entire paper. Unlike the abstract, more details may be presented, but brevity and explicitness are always noble.

List of Literature

Usually, 20-50 references are proper, but if possible, lessen the review papers/books and increase the newest literatures. Please refer to the template.