Flaky graphene oxide (GO) nanoparticles (NPs) were synthesized using Hummer’s method and then capped with polyethylene glycol (PEG) by an esterification reaction, then loaded with Nigella sativa (N. sativa) seed extract. Aiming to investigate their potential use as a smart drug delivery system against Staphylococcus aureus and Escherichia coli, the spectral and structural characteristics of GO-PEG NPs were comprehensively analyzed by XRD, AFM, TEM, FTIR, and UV- Vis. XRD patterns revealed that GO-PEG had different crystalline structures and defects, as well as a higher interlayer spacing. AFM results showed GONPs with the main grain size of 24.41 nm, while GONPs–PEG revealed graphene oxide aggregation with the main grain size of 287.04 nm after loading N. sativa seed extract, which was verified by TEM examination. A strong OH bond appeared in FTIR spectra. Furthermore, UV- Vis absorbance peaks at (275, 284, 324, and 327) nm seemed to be correlated with GONPs, GO–PEG, N. sativa seed extract, and GO –PEG- N. sativa extract. The drug delivery system was observed to destroy the bacteria by permeating the bacterial nucleic acid and cytoplasmic membrane, resulting in the loss of cell wall integrity, nucleic acid damage, and increased cell-wall permeability.

In this work, Graphene oxide (GO) was synthesized by Hummer’s method using graphite rod. Used organic chemical materials to active (GO – COOH) for esterification reaction between the graphene oxide carboxylic acid group and the Polyethylene glycol (PEG) hydroxyl group. Graphene oxide (GO) was conjugated to PEG4000 (medical polymer). The composite (GO – PEG) characterization by XRD, FTIR, UV-Vis and AFM. In UV-Vis GO showed a sharp peak at 275 nm whiles the peak of (GO – PEG) appear at 284 nm. A strong OH bond appear in Fourier transforms infrared spectroscopy (FTIR) spectra, C –H bond of (GO – PEG) also showed. In XRD pattern GO have a sharp peak appear at 2θ = 11.83° that related to 001 with d-spacing of 7.76 Å while functionalization of GO – PEG 4000 conform by broad peak at 2θ= 23.38s with d-spacing of 3.8 Å. Atomic force microscopy (AFM) images, GO image shows Graphene oxide sheet with main grain size is 24.41 nm, In GO – PEG4000 shows aggregation of Graphene oxides with PEG4000 the main grain size increase with functionalize to 287.04 nm.

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The research describes the effect of space debris on near-Earth space in order to reveal the concept of space debris composition and origin of debris, to determine the effect of space debris on space orbital flights by discussing the spatial distribution of debris, the Collisions of spacecraft with debris and their consequences, the probability of collisions of spacecraft with debris, and Measures to limit debris contamination of near-Earth space. Also, the expected consequences of debris contamination of space and the Earth have been identified in this research as the frequency of dangerous encounters between debris and vehicles will almost double. By 2059, this figure will quadruple. If we translate this prediction into absolute numbers, it turns out that in 2019 satellites and space debris converged 20 thousand times a week, and in 2059–50 thousand. Now the number of such events is about 13 thousand per week. The need to track hazards and ensure evasive maneuvers will significantly increase the cost of space missions. The research describes the ways to remove space debris from orbit by using jet propulsion devices (both high and low thrust), aerodynamic braking means, Collection of artificial objects using special spacecraft and their subsequent withdrawal, and using a solar sail.