Wood/inorganic hybrids fall under the category of new functional nanocomposite materials because of being a combination between organic and inorganic materials with their respective advantages and excellent performance. Synergistic effects resulting from the physical or chemical interactions between the inorganic and wood components have produced such properties as improved thermal stability, UV-resistance, hydrophobic, mechanical and dimensional stability . Currently, deposition of a thin solid inorganic nanomaterial coating imbedded onto the wood surface has great potential to improve the inherent wood defects (like moisture deformation, easily burnt, etc.) and simultaneously to grant novel performances (like super-hydrophobic, self-cleaning, UV–resistance, or others) . The present focus among the thin solid inorganic nanomaterial coatings is mainly metal semiconductor materials, like TiO2 [3,4], SiO2 , ZnO , CeO2 , and so on [8,9,10,11,12,13]. Several research works paid less attention to magnetic nanostructure materials deposited onto the wood surface.
With the rapid development of wireless communications indoors and outdoors, the electromagnetic interference (EMI) pollution has become much more serious. The electromagnetic waves may cause interception and malfunction of the performance of electrical equipment in medical, military and aircraft systems or even lead to radiative damage of the human body [7,14]. Therefore, it is necessary to exploit new types of microwave-absorption materials with excellent properties, such as a wide frequency range, strong absorption, low density, high resistivity, etc.
Magnetic nanomaterials/wood hybrids would be potential candidates for microwave absorption, especially when wood serves as interior decorations due to its renewability, attractive surface, sound insulation, temperature- and humidity-controlling performances. It may be a reasonable choice for wave absorption if the wood surface is embedded with a thin solid magnetic film with a trivial change of appearance. Previous studies have been conducted showing that the wood surface can be considered as an effective substrate containing plentiful hydroxyl groups for the nucleation and growth of inorganic nanomaterials. Publicly reported pathways for the deposition of magnetic materials are the sol-gel method [15,16,17], electroless deposition , the hydrothermal process [19,20] and physical padding. Among these methods, the hydrothermal method was a feasible and efficient pathway for growing magnetic nanomaterials with high product purity and homogeneity, crystal symmetry, narrow particle size distributions, a lower sintering temperature, a wide range of chemical compositions and single-step processes, as well as for the growth of crystals with polymorphic modifications [21,22,23,24,25,26,27]. Herein, we employed a facile low temperature hydrothermal process for the growth of nanooctahedra MnFe2O4 on the wood surface. The as-prepared MnFe2O4/wood (MW) composite showed a superior soft magnetism, fire resistance and electromagnetic absorption. The saturation magnetization of the MW was 28.24 emu/g with extremely small hysteresis loops, and low coercivity indicated that this composite was an excellent soft-magnetic material. The MW also exhibited a good fire resistance property due to it not being burnt in the first 20 s, while only 6 s were needed for the untreated wood. Additionally, this composite is a good electromagnetic absorption material due to its minimum reflection loss of −9.3 dB at 16.48 GHz. Thus, the MW has great potential in the fields of special decoration and indoor electromagnetic wave absorbers.
2. Experimental Details
All chemicals were supplied by Boyle chemical Co. Ltd., Shanghai, China. and used without further purification. The wood slices were cut with sizes of 20 mm (length) × 10 mm (width) × 5 mm (height), and then, the slices were ultrasonically rinsed in deionized water for 30 min and dried at 80 °C in a vacuum.
2.2. One-Pot Hydrothermal Synthesis of MW
In a typical synthesis, FeCl3·6H2O and MnSO4·H2O in a stoichiometric ratio of 2:1 were dissolved in 80 mL of deionized water under magnetic stirring at room temperature. The obtained homogeneous mixture was transferred into a 100 mL Teflon-lined stainless autoclave. Wood specimens were subsequently placed into the above reaction solution, and the pH value was adjusted via adding a certain amount of ammonia solution. The Teflon-lined stainless-steel autoclave was sealed and heated to 120 °C for 8 h. Subsequently, the autoclave was left to cool down to room temperature. Finally, the prepared magnetic wood samples were removed from the solution, ultrasonically rinsed with deionized water for 30 min and dried at 45 °C for over 24 h in a vacuum.
The surface morphologies of the samples were characterized by scanning electron microscopy (SEM, Quanta 200, FEI, Eindhoven, The Netherlands). Crystalline structures of the samples were identified by the X-ray diffraction technique (XRD, D/MAX 2200, Rigaku, Tokyo, Japan) operating with Cu Kα radiation (λ = 1.5418 Å) at a scan rate (2θ) of 4° min−1, an accelerating voltage of 40 kV and the applied current of 30 mA ranging from 10–80°. Changes of chemical groups were recorded via a Fourier transform infrared spectroscopy (FT-IR, Magna-IR 560, Nicolet, Madison, WI, USA). XPS analysis was characterized by an X-ray photoelectron spectrometer (XPS, ESCALAB 250 XI, Thermofisher Co., Bridgewater, NJ, USA). The magnetic properties of the composites were measured by a vibrating sample magnetometer (VSM, Model 7404, LakeShore Cryotronics Inc., Westerville, OH, USA) at 300 K. The thermal performances of the MW were examined using a thermal gravimetric analysis (TGA, SDT Q600, TA Instruments, New Castle, DE, USA) heating rate of 4 °C/min and under an N2 flow rate of 50 mL/min. The relative permeability and permittivity were obtained on an Agilent N5244A PNA-X network analyzer (VNA, Agilent Technologies Inc., Richardson, TX, USA) in the frequency range of 2–18 GHz for the calculation of reflection loss (RL) by the coaxial reflection/transmission method based on the NRW (Nicolson-Ross-Weir) method. The sample containing composite materials and paraffin wax with the mass ratio of 2:3 was pressed into toroidal-shaped samples (Φout = 7.00 mm, Φin = 3.04 mm, thickness = 2 mm) for microwave measurement. The simulated reflection loss (RL) was calculated from the measured parameters according to the transmission line theory.
3. Results and Discussion
Figure 1a shows the XRD patterns of the untreated wood and the MnFe2O4/wood composite. The strong diffraction peaks at 16.1° and 22.6° were equivalent to the crystalline region of the cellulose of the wood (Figure 1a). In addition, the diffraction peaks at 17.9°, 30.3°, 35.6°, 43.3°, 53.5°, 57.1° and 62.8° could be attributed to the diffractions of the (111), (220), (311), (400), (422), (511) and (440), which confirmed the presence of the MnFe2O4 (JCPDS 73-1964) with a phase-pure spinel structure on the wood surface. This result revealed that the MnFe2O4 was successfully grown on the wood surface.
Figure 1b showed the FTIR spectra (400–4000 cm−1) of the untreated wood (UW) and the MW. The main absorption bands of the MW were located at 3416 cm−1, 1168 cm−1 and 1050 cm−1, corresponding to the stretching vibrations of O–H, C=O and C–O, respectively, which were attributed to the chemical contents of the wood substrate (hemicellulose, cellulose and lignin). The peak of UW at 3431 cm−1 was ascribed to stretching vibrations of the hydroxyl groups of the wood. Then, this peak shifted to the lower wavenumbers of 3416 cm−1 after coating MnFe2O4 on the wood surface, indicating the formation of the hydrogen bonding interaction between the nanooctahedra MnFe2O4 and the wood . The peaks at 2922 cm−1 and 2950 cm−1 were caused by the stretching vibrations of –CH3 and –CH2, but these peaks in the MW spectra significantly decreased; and the peak at 1740 cm−1 (the carbon and oxygen double bonds) only existed in the UW spectra . These phenomena were attributed to the hydrolysis of fatty acids by hydrothermal reaction under the alkaline conditions. Simultaneously, the absorption peaks at 587 cm−1 were intrinsic vibrations of the manganese ferrite .
The surface morphologies of the UW and MW by scanning electron microscopy are exhibited in Figure 2. Some fibrils and the inner surface of the lumen could be clearly observed on the microstructure of a longitudinal section of the UW surface. After the hydrothermal process, the wood surface was compactly covered by MnFe2O4 in Figure 2b. The inset of (b) shows the size distribution of nanooctahedra MnFe2O4 with an average particle size of 0.68 nm and a size distribution width of 0.5–1 μm. Figure 2c shows the MnFe2O4 with an octahedral shape aggregated over the wood surface by a compact manner, and many small nanoparticles also were equipped on this nanooctahedra MnFe2O4 surface. In order to further investigate the fine features of the nanooctahedra MnFe2O4, the MW was studied by a zoomed-in SEM after ultrasonic treatment with 1800 W for 30 min (Figure 2d). The zoomed-in SEM showed the nanooctahedra MnFe2O4 still tightly covered the wood surface, but a small fraction of the MnFe2O4 and the bare wood surface appeared to rupture. These results indicated that the nanooctahedra MnFe2O4 were closely integrated with the wood surface by a strong interaction. In addition, the surface of nanooctahedra MnFe2O4 became very clean, which might reveal that small nanoparticles were adsorbed on the surface of nanooctahedra MnFe2O4 by a physical process.
X-ray photoelectron spectroscopy (XPS) is a powerful technique for studying the elemental composition and chemical oxidation state of the surfaces. Figure 3a shows the survey-scan XPS spectra of UW and MW; elemental O and C coexisted in both samples, where the C element was attributed to the wood substrate from cellulose, lignin and hemicellulose. In addition, besides O and C elements, the survey-scan spectrum of the MW revealed iron and manganese peaks, which should come from MnFe2O4 nanoparticles on the wood surface. Figure 3b,c shows the Fe2p and the Mn2p spectra, respectively. For Fe, the two main peaks Fe2p1/2 and Fe2p3/2 at 724.73 eV and 711.13 eV, respectively, indicate the presence of Fe3+ cations by comparison with the Fe2p3/2 peaks of Fe2O3 and Fe metal [30,31,32,33]. Two sharp peaks for the Mn2p1/2 and Mn2p3/2 at 653.23 eV and 641.43 eV, respectively, indicate the presence of Mn2+ cations by comparison with the MnO .
Figure 3d and Table 1 illustrated the O1s spectra and binding energy of the UW and MW samples, respectively. The broad peak of O1s at the UW spectrum could be fitted by two peaks at binding energies of 533.18 eV and 531.83 eV, respectively. The largest peak at 533.18 eV was attributed to the carbon-oxygen bond on the wood, such as cellulose, lignin and hemicellulose. The other peak at 531.83 eV was assigned to the other oxygen from OH, H2O and carbon-oxygen double bonds from the wood substrate. By contrasts, the main peak on the O1s spectrum of MW appeared at binding energies of 530.23 eV, which was compatible with oxygen in metal oxides, such as Fe–O and Mn–O [35,36]. Furthermore, it is easily observed that the peak at 531.82 eV had been shifted to 531.55 eV and relatively higher than before the reaction. That strongly indicated that the MnFe2O4 nanoparticles had been successfully located on the wood surface by the hydrogen bond after hydrothermal treatment under this work.
Fe3+ + 3OH–⇋Fe(OH)3(s); Mn2+ + 2OH–⇋ Mn(OH)2(s)
Fe(OH)3(s) + (n-3)OH–⇋ Fe(OH)n3-n; Mn(OH)2(s) + (n-2)OH–⇋ Mn(OH)n2-n
Mn(OH)n2-n + Fe(OH)n3-n → MnFe2O4 + H2O
On the basis of the results mentioned above, a schematic illustration of the creation of nanooctahedra MnFe2O4 on the wood surface through a low temperature hydrothermal process is proposed in Figure 4. The precursors (FeCl3·6H2O and MnSO4·H2O) were dissolved into the deionized water and provided Mn2+ and Fe3+ ions at first. After adding ammonia solution, the Mn2+ and Fe3+ ions with the hydroxyl ions in the solution transformed into Mn hydroxides and Fe hydroxides, respectively. The Fe and Mn hydroxides dissolved in the mixed solution because of the presence of high concentrations of the ammonia and converted to the Mn(OH)n2-n and Fe(OH)n3-n with massive hydroxyl groups. Then, the Mn(OH)n2-n and Fe(OH)n3-n, as the growth unit, formed the MnFe2O4 nanocrystal nucleus by the dehydration reaction. Additionally, the plentiful hydroxyl groups of the wood surface absorbed the MnFe2O4 nanocrystal for its the OH-rich surface that could be due to the high surface activity and large surface-to-volume atomic ratio on the MnFe2O4 nanoparticle’s surface. Finally, with the hydrothermal advanced, the MnFe2O4 nanocrystal developed a more stable MnFe2O4 layer on the wood surface and formed the MnFe2O4/wood composite.
Figure 5 shows the magnetization-field curves of MW at 298 K. The saturation magnetization of MW was 28.24 emu/g, and it exhibited small hysteresis loops and low coercivity (<±5 Oe), as shown in the inset (a). Therefore, the MW showed a soft magnetism behavior [37,38,39]. The lower right corner illustration shows the camera images of the magnet attracting samples. In the inset (b), the UW lacks the response by a magnet, and the MW could be easily removed from the desktop by a magnet. These results revealed that the MW is an excellent soft magnetic material with sensitive magnetic response .
The thermal stability of MW and UW was determined by TG and DTG under nitrogen atmosphere as shown in Figure 6
The word “synthesis” is defined as a combination of elements to form a connected whole. Thus, a synthesis essay definition is an essay that combines different ideas into a whole to prove a point (otherwise called the thesis). Often, it comes with a text that you should analyze.
Table Of Contents
A key factor of writing a synthesis essay is an analysis of a given text or a prompt. In order to successfully analyze it, you must comprehend the text’s purpose, rhetoric, and the argument that the author’s claim, in other words, you are answering the question: “So what?”. Then, you must build your own claim, and write an essay around that.
Most Common Topics
A synthesis essay prompt must be negotiable. Like in the EssayPro's example above, Andrew Jackson’s negative views on Native American people were widely supported, today, however, they would be appalling. Depending on your assignment, you may have to choose a primary text. Choose a text that might have opposing viewpoints.
Good topics would be ones that are debatable, for example:
- Daylight savings
- Minimum wage
- Immigration policy
- Global warming
- Gun control
- Social media
How Do I Write A Thesis?
Once you pick a topic of your paper, read your sources and establish your position. Make sure you thoroughly analyze the sources and get a good understanding of them, structure your claim or argument and write your thesis.
Example: Andrew Jackson’s fear of the Native American “savages” reflects the prejudices and ideas of the colonist people in the Union and the Congress.*
How Do I Write An Outline?
Creating an outline will help maintain the structure of your paper. If your essay is split into three parts, split your outline into three chunks. Paste supporting evidence, sub-arguments, and specific points in the appropriate sections. Make sure that every point somehow proves the claim in your thesis. Extra information or tangents will only hinder your essay. However, if information goes against your central claim, then you should acknowledge it as it will make your essay stronger. Make sure you have read all of your sources. When writing about the sources, do not summarize them; synthesis denotes analysis, not plot-summary.
- Main point 1
- Main point 2
- Main point 3
- Main point 1
- Evidence (quote from a source)
- Analysis of Evidence
- Main point 2
- Evidence (quote from a source)
- Analysis of Evidence
- Main point 3
- Evidence (quote from a source)
- Analysis of Evidence
- Restate main points and answer unanswered questions
Read more about how to write a great INTRODUCTION
How Do I Format My Essay?
The format depends on what style is required by your teacher or professor. The most common formats are: MLA, APA, and Chicago style. APA is used by fields of Education, Psychology, and Science. MLA is used for citing Humanities, and Chicago style is used for Business, History, and Fine Arts. Purdue Owl is a format guide that focuses mainly on MLA and APA, and Easybib is a citation multitool for any of your external sources.
Some key points are:
- Times New Roman 12 pt font double spaced
- 1” margins
- Top right includes last name and page number on every page
- Titles are centered
- The header should include your name, your professor’s name, course number and the date (dd/mm/yy)
- The last page includes a Works Cited
Some key points are:
- Times New Roman 12 pt font double spaced 1” margins
- Include a page header on the top of every page
- Insert page number on the right
- An essay should be divided into four parts: Title Page, Abstract, Main Body, and References.
How do I write an AP English Synthesis Essay?
AP English Language and Composition is an extremely rigorous course that requires you to write essays that demonstrate deep understanding of the subject matter. In fact, if on the AP exam, your essay has perfect grammar and structure, you might still be awarded just 1 out of 9 points for not “defending, challenging, or qualifying your claim.” Sounds difficult, but it is doable. Before entering any AP class, it is best to read over the course overview and become familiar with the exam.
While writing, focus on the three branches of the AP English and Composition course: argument, synthesis, and rhetorical analysis.
Argument is the easiest component; create your claim and find specific supporting evidence. Convince your reader that you are right.
Synthesis requires you to read into multiple perspectives and identify an agreement and a disagreement between sources. This step is crucial to finding your own claim.
Rhetorical analysis deals with the author and his intentions. What was their purpose for writing this? Who is their intended audience? How does the author appeal to the audience and how does he structure his claim?
There are two acronyms that are helpful with the three AP Lang writing branches.
Tip #1: SOAPS
Example text: Andrew Jackson’s speech to the Congress about sending Native Americans to the West.
Speaker: Identify the speaker of the piece, then analyze for bias and apply any prior knowledge that you have on the speaker.
Example: President Andrew Jackson had a bias against Native Americans. A piece written by Andrew Jackson about Native Americans will probably be written with a bias against him.
Occasion: Determine the time and the place of the written text, then identify the reason the text was written. Even if you aren’t sure of the reason, assume one and make your claim around it.
Example: Andrew Jackson was in office from 1829 to 1837. At this time, the Congress sent Native Americans to the West in order to clear the land for the colonists. Jackson was the one who made the proposal.
Audience: Who was the text directed to?
Example: Andrew Jackson’s speech was directed to a council.
Purpose: What is the text trying to say? Here, you analyze the tone of the text.
Example: Andrew Jackson appeals to pathos by calling Indians “savages”. His purpose is to portray Native Americans in a negative light, so the Congress passes the Indian Removal Act.
Subject: What is the main idea? What is the claim?
Example: Andrew Jackson wants the Congress to pass the Indian Removal Act because he believes Native Americans are uncultured and savage people.
Tip #2: Logos, Ethos, and Pathos
As you’ve probably learned before, Logos appeals to reason, Pathos appeals to emotion, and Ethos appeals to moral philosophy or credibility. However, for the AP Lang exam requires a wider understanding of the three.
If the text uses facts, statistics, quotations, and definitions, the speaker is appealing to Logos. Constituting various backup information is an extremely effective for people who want to persuade.
If the text uses vivid imagery and strong language it denotes Pathos, which is used to connect the audience to a piece emotionally; it is hardest to change the mind of a person who is linked to a subject via a strong emotion.
If the text attempts to demonstrate the speakers reliability or credibility, it is a direct appeal to Ethos. Using the example above, Andrew Jackson could have appealed to Ethos by stating the fact that he is the President of the United States, and thus, knows what is best for the union.
Often, Logos, Ethos, and Pathos lead to the use of logical fallacies.
Tip #3: DIDLS
This is a good shorthand for all textual analysis. While reading a text, try to pinpoint Diction, Imagery, Details, Language, and Sentence Structure in a piece. If anything stands out, add it to your analysis.
- High range essay (8-9 points)
- Effectively develops a position on the assigned topic.
- Demonstrates full understanding of the sources or text.
- Correctly synthesizes sources and develops a position. The writer drives the argument, not the sources.
- The writer’s argument is convincing.
- The writer makes no general assertions and cites specific evidence for each point. His/her evidence is developed and answers the “so what?” question.
- The essay is clear, well-organized, and coherent. It is a stand alone piece rather than an exam response.
- Contains very few grammatical and spelling errors or flaws, if any.
Note: 8-9 essays are an extreme rarity. A strong ‘7’ paper can jump to an 8-9 if the writing style is mature and perceptive.
Middle-Range Essay (57)
- Adequately develops a position on the assigned topic.
- Demonstrates sufficient understanding of the ideas developed in sources
- Sufficiently summarizes the sources and assumes some control of the argument. ‘5’ essays are less focused than ‘6’ and ‘7’.
- The writer's argument is sufficient but less developed.
- Writer successfully synthesizes the sources and cites them.
- Writer answers the “So what?” question but may use generalizations or assertions of universal truth. Writer cites own experience and specific evidence.
- Essay is clear and well organized. ‘5’ essays less so.
- Contains few minor errors of grammar or syntax.
Note: A ‘7’ is awarded to papers of college-level writing.
A ‘5’ on one of the AP English Language and Composition essays designates a 3 on the AP exam. It most likely relies on generalizations has limited control of the claim and argument. ‘5’ essays often lose focus and digress.
Low-Range Essays (1-4)
- Inadequately develops a position on the assigned topic.
- The author misunderstands and simplifies the ideas developed in the sources.
- Over-summarizes the sources, lets the sources drive the argument.
- Writer has weak control of organization and syntax. Essay contains numerous grammatical/spelling errors.
- Writer does not cite the sources correctly, skips a citation, or cites fewer than the required minimum of the sources.
- Notes: ‘4’ or ‘3’ essays do assert an argument but do not sufficiently develop it.
- A ‘2’ essay does not develop an argument.
- A 1-2 essay has severe writing errors and do not assert a claim.
Synthesis Essay Example
Essay Writing Advice From Our Professional Team
James Owen, online essay writer from EssayPro
The article reviews the basics of how to write a synthesis essay as well as how to dissect and analyze text when writing an AP English essay. One thing I would like to reemphasize is the importance of your thesis statement. When you write an essay for class or exam, make sure to state your argument clearly. If the reader of your essay doesn’t understand your point of view then what you’ve written is futile.
My advice is: when writing an essay in a short period (such as in an exam room) make sure to articulate your argument in every paragraph and connect every single one of your ideas to the thesis. My tip is to write your thesis down on a piece of paper and reread it at every point to ensure that the information applies and reinforces what you’ve stated in your thesis. This tip also goes for when you are writing a longer piece of writing, as it is very easy to lose focus and stray away from your main point.
Struggling With Writing an Essay?
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