Study and Characterization of Fe 3 O 4 -PEG Nanoparticles Using The Co-Precipitation Method For The Production of Permanent Magnets

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Introduction
Fe 3 O 4 nanoparticles have a great advantage in salinity technology, so this new material development is urgently needed concerning the exploration of raw materials, synthesis methods used, required calcification methods, and signal amplification [1] - [4].In terms of basic ingredients, of course, the materials used are synthetic and alternative ones that are environmentally friendly and low in toxins.While in the main problems regarding the method, it is probable that the method used in the restoration, the method synthesis, which results in a monodisperse scalable nanoparticle product in the method used and also allows a single domain from the behavior of the particles in the method used, also requires a method that is environmentally friendly and does not use the balance of alcohols in the synthesis process.
Fe 3 O 4 is a black powder material with strong magnetic properties.In addition, magnetite also exhibits super-parallel magnetic behavior for grain sizes below 10 nm.Polyethylene glycol 6000 is polyethylene glycol H(O-CH 2 -CH 2 ) n OH, and the value of n is between 158 and 204 [5].It has the following characteristics: smooth white powder and ivory-yellow white pieces, practically unbounded in origin.Solubility is easily soluble in flow, in ethanol (95%) chloroform, and in ether.The average molecular weight is not less than 7000 and not more than 9000.Its efficacy is as an additive [6] This research was carried out to disperse Fe 3 O 4 nanoparticles with the variation of the composition of PEG-6000 using the co-precipitation method.The test used XRD, SEM, VSM, and FTIR.

Research Procedures
In this research, the process of synthesizing natural iron palsy with polyethylene glycol (PEG) was carried out using the Co-Precipitation method.The research includes raw material preparation, precipitate drying, calcination, and calcification processes.

Preparation of Nanoparticle of Fe 3 O 4 /PEG
In this research, the synthesis process of Fe 3 O 4 /PEG nanoparticles was carried out using the coprecipitation method.According to the ratio, the material used to manufacture Fe 3 O 4 nanoparticle powder is a natural iron pallant in PEG.First, mix natural iron and PEG into 50 ml of DI water, then stir using a magnetic stirrer for 1 hour at a speed of 300 rpm at a temperature of 50°C to produce a homogeneous solution.The homogeneous solution was then forged into a solution of NH 4 OH in DI water with a concentration of 6.5 M. Then the mixed solution was stirred for 1 hour at a speed of 500 rpm and a temperature of 50°C.Then the result of the mixture will produce a precipitate powder.Next, the precipitate was separated from the impurities using a permanent magnet and washed with DI water; the wet powder precipitate was washed with 10 ml of ethanol and heated on a magnetic stirrer at 50°C; after the colloid was formed, it was dried in an oven for 1 hour at 50°C.After the effluent dried, the powder was ground using a mortar to produce

Characterisation of Fe 3 O 4 / PEG Nanoparticle
FTIR tested the structure of chemical compounds or chemical groups of Fe 3 O 4 /PEG nanoparticles.To evaluate the effect of composition on structure in identifying the crystalline phase of Fe 3 O 4 /PEG nanoparticles using X-Ray Diffraction (XRD).The effect of magnetic properties on the molar ratio of nanoparticles Fe 3 O 4 /PEG was tested using a vibrating sample magnetometer (VSM).The morphological properties of the material were measured using SEM.

X-Ray Diffraction (XRD) Analysis
Figure 1 shows the XRD patterns of the samples.Each material shows hkl peaks (110), ( 200), ( 311), ( 222), ( 400), (422), and (511).One of the characteristics of phase Fe 3 O 4 is that it has the highest intensity at 34.59 with the hkl peak point (311).The PEG phase did not appear in the XRD test, so no reaction occurred and functioned as a template.The width or height of intensity in the XRD test results also determines the size of a crystal.The higher the narrowing of a peak, the greater the crystallite size, and vice versa.If the peak narrows shorter and lower, then it can be said that the crystallite size is small [7].

Scanning Electron Microscope (SEM) Analysis
The SEM results are given in Figures 2, 3, and 4. Based on Figure 2, The agglomeration in sample 1 has been evenly distributed and not clustered, making it easier to identify the particles; generally, agglomeration occurs because of the high temperature, where the agglomeration is called the formation of particles.So the histogram on the particle size of the first sample is good.The particle distribution ranges from 123-138 with a frequency of 2.0, where the frequency is the number of frequencies in 1 nm.Based on Figure 3, the agglomeration in sample 2 has also been evenly distributed and not clustered, making it easier to identify the particles, in which case the agglomeration occurs due to the high temperature where the agglomeration is called particle formation.So that the histogram on the particle size of the first sample is good because the R-Square in X c, which is refined, has a value; R-Square = 0.99996; X c = 172.08928± 1.00923 because the acceptable range of R-Square values ranges from 0.85 -1.0 so that it fulfills the conditions of the histogram.The particle distribution ranges from 10-80, having a frequency of 2 in terms of frequency, namely the number of frequencies in 1 nm.Based on Figure 4, the agglomeration of sample 3 has also been evenly distributed even though some are clustered, but it can make it easier to identify the particles where the agglomeration occurs due to the high temperature; the agglomeration is called particle formation so that the histogram of the particle size of the first sample is acceptable.The particle distribution ranges from 60-96 with a frequency of 2.

Vibrating Sample Magnetometer (VSM) Analysis
Figure 5 depicts the hysteresis of nanoparticles Fe 3 O 4 -PEG.According to [8], the hysteresis curve has experienced the particle effect.Particles also tend to affect the magnitude of the curvature of hysteresis in accordance with [9], even for all particle sizes above 40 nm in the presence of permanent magnetic magnets.Based on Table 2, in compositions 8:2 and 10:0, there is an increase in the value of coercivity; this occurs due to agglomeration in the powder.In the saturated value, there is a gradual decrease in remanence and coercivity that fluctuates up and down due to agglomeration and gaps between particles in the three samples.
Then there is a decrease in the value of ups and downs in the coercivity affected by the size of a particle.The smaller the particle size, the easier it is for the material to crack and release its magnetic properties when the magnetic field is recognized from the outside and vice versa [10].

Fourier Transform Infra-Red (FTIR) Analysis
FTIR is one tool widely used to determine molecular vibrations that can be used to predict the structure of chemical compounds or chemical groups.Therefore, focusing on the position of the sample and then focusing on the detector is a combination of different wavelengths.Wavelength used was 500-4000 (/cm).6, there is a shift in peak vibration caused by changes in the energy of the Fe-O vibrations located in absorption between 500-1000 cm, allowing PEG absorption by Fe atoms to occur.It has been synthesized in the presence of ultrasonic waves.However, the FTIR spectra show that there is another absorption at 3400 cm −1 which is indicated to be from the -OH group of water, and absorption in the 1600 cm −1 area, which is considered to arise from an impurity H-C=O.

Conclusion
In summary, the structure of the Fe 3 O 4 -PEG nanoparticles produced using the Co-Precipitation method has a single phase, namely the magnetite phase (Fe 3 O 4 ), and forms a spinel cubic crystal structure with a lattice parameter of 8.513 Å.The results of the SEM test show that the sample is not homogeneous or homogeneous, as indicated by the presence of a gap and agglomeration of particles in each sample.Magnetic properties of nanoparticles Fe 3 O 4 -PEG with VSM testing showed that the parameters of the magnetic properties of saturation (M s ) averaged 23.9763735 emu/g, magnetic remanence (M r ) averaged 5.14865198 emu/g with an average coercivity of 125.139457033 emu/g.The functional group of nanoparticles Fe 3 O 4 -PEG from the FTIR test showed a shift in the vibration peak, which experienced a change in the vibrational energy of Fe-O at an absorption of 500-1000, then showed a -OH group at an absorption of 3400/cm.

Figure 6 .
Figure 6.FTIR spectrum of Fe 3 O 4 with additions of PEG

Table 2 .
Data of testing results from VSM