New promising samples of silver nanoparticles: (SNPs)-chitosan (CT) nanocomposite (NC) abbreviated as (SNPs-CTNC) have been synthesized and characterized using the novel green chemistry approach. All the synthesized formulations showed innovative corrosion inhibition for the mild steel samples in the cooling water system. The experimental conditions for the green synthesis of eco-friendly silver nanoparticles (SNPs) using chitosan (CT) biopolymer as both reducing and protecting coating agent for SNPs have been optimized. The synthesis route presented herein was performed by the reduction of silver nitrate (AgNO₃) by CT in an autoclave reactor vessel under 1 bar applied pressure at the reaction temperature of 120 °C and various contact time (2, 4, 8, and 16 h) between (AgNO₃) and chitosan (CT). The four prepared samples of SNPs-CT NC have been abbreviated in terms of the reaction or the contact time as (2 h, 4 h, 8 h, and 16 h). The four SNPs-CT NC samples were characterized using: UV–Visible spectroscopy; Fourier transform infrared (FTIR); X-ray diffraction (XRD) and transmission electron microscopy (TEM). The SNPs coated by chitosan biopolymer showed good antimicrobial activity, and have extremely fine particle size approaching that of the quantum dots nanoparticles. The particle size distribution of all the prepared nanocomposite samples lies around the nanometer scale range of 3–6 nm. The corrosion rate of the standard corrosion coupons of mild steel in the industrial chilled water in the absence and the presence of different concentrations of SNPs-CTNC samples were measured by the gravimetric method as well as the electrochemical impedance spectroscopy (EIS) and DC-potentiodynamic polarization techniques. The inhibition efficiency (%IE) of SNPs-CTNC achieved up to 97–98% at the concentration of 150 ppm SNPs-CTNC of all the prepared samples (from chemical gravimetric weight loss results). The inhibition efficiency (%IE) of the best performance SNPs-CTNC sample (8 h) showed inhibition efficiency above 80% at 100 ppm (as evident by the further electrochemical techniques: impedance and potentiodynamic polarization results). Both the inhibition efficiency and the antimicrobial activity of SNPs-CT NC samples remained unchanged on aging for twelve months storage where: The percent inhibition efficiency of all SNPs-CTNC samples remain above the percentage of 93% on aging for this relatively long storage time period, the sample 2 h showed the most constant inhibition efficiency (97.6% for the fresh prepared sample and 97.5% for the twelve months aged sample). In addition, the scanning electron (SEM) micrographs have been showed that: A clean and bright metal surface was maintained after the exposure to the chilled water in the presence of SNPs-CTNC along the immersion time of one year. The nanocomposite samples acted by spontaneous physisorption on the metal surface as indicated by the negative value of ΔG°_adsorption (equals −18.002 kJ·mol⁻¹). The adsorption data represented in the surface coverage (θ) were found to be linearly fitted well to Langmuir adsorption isotherm with positive and relatively large value of the binding equilibrium constant (K) (43.6) that represented the strong attraction forces between the adsorbed nanocomposite particles and the metal surface. The mode of the adsorption of these nanocomposite particles on the metal surface has been interpreted in terms of the electrostatic interaction between the negatively charged colloidal SNPs and the positively the charged metal surface.

银纳米颗粒的新有希望的样品：（SNPs-壳聚糖（CT）纳米复合物（NC）缩写为（SNPs-CTNC））已经使用新颖的绿色化学方法进行了合成和表征。所有合成的配方对冷却水系统中的低碳钢样品均显示出创新的缓蚀性能。优化了使用壳聚糖（CT）生物聚合物作为SNP的还原剂和保护剂的绿色合成环保银纳米颗粒（SNP）的实验条件。本文提出的合成路线是通过在压力为120 bar的反应温度和各种接触时间（2、4、8和16）下在高压釜反应器中在1 bar施加压力下通过CT还原硝酸银（AgNO ₃）进行的。 h）在（AgNO ₃）和壳聚糖（CT）。在反应或接触时间（2h，4h，8h和16h）方面，已将四个制备好的SNPs-CT NC样品缩写。使用以下方法对这四个SNPs-CT NC样品进行表征：紫外可见光谱；傅立叶变换红外（FTIR）; X射线衍射（XRD）和透射电子显微镜（TEM）。壳聚糖生物聚合物包被的SNP具有良好的抗菌活性，并具有接近量子点纳米粒子的极细粒度。所有制备的纳米复合材料样品的粒径分布均在3–6 nm的纳米级范围内。通过重量分析法，电化学阻抗谱法（EIS）和直流电位分析法测量了在不存在和存在不同浓度的SNPs-CTNC样品的情况下，工业冷水中低碳钢的标准腐蚀试样的腐蚀速率。极化技术。在所有制备的样品中，SNPs-CTNC的浓度为150 ppm时，SNPs-CTNC的抑制效率（％IE）达到97-98％（根据化学重量分析的失重结果）。性能最佳的SNPs-CTNC样品（8 h）的抑制效率（％IE）在100 ppm时显示出80％以上的抑制效率（进一步的电化学技术证明：阻抗和电位动力学极化结果）。SNPs-CT NC样品在储存十二个月后的抑制效率和抑菌活性均保持不变，其中：在相对较长的存储时间段内，所有SNPs-CTNC样品的抑制百分比在衰老率上均保持在93％以上，样品2 h表现出最恒定的抑制效率（新鲜制备的样品为97.6％，老化的十二个月样品为97.5％）。此外，扫描电子显微镜（SEM）的照片显示：在SNPs-CTNC存在的情况下，在一年的浸泡时间中，在有SNPs-CTNC存在的情况下，将其暴露于冷水中后，可以保持干净，明亮的金属表面。纳米复合材料样品通过在金属表面上自发发生物理吸附作用，如ΔG°的负值所示 在此相对较长的存储时间内，所有SNPs-CTNC样品的抑制率百分比均保持在93％以上的老化率之上，样品2 h表现出最恒定的抑制率（新鲜制备的样品为97.6％，而新制备的样品为97.5％）。十二个月大的样本）。此外，扫描电子显微镜（SEM）的照片显示：在SNPs-CTNC存在的情况下，在一年的浸泡时间中，在有SNPs-CTNC存在的情况下，将其暴露于冷水中后，可以保持干净，明亮的金属表面。纳米复合材料样品通过在金属表面上自发发生物理吸附作用，如ΔG°的负值所示 在此相对较长的存储时间内，所有SNPs-CTNC样品的抑制率百分比均保持在93％以上的老化率之上，样品2 h表现出最恒定的抑制率（新鲜制备的样品为97.6％，而新制备的样品为97.5％）。十二个月大的样本）。此外，扫描电子显微镜（SEM）的照片显示：在SNPs-CTNC存在的情况下，在一年的浸泡时间中，在有SNPs-CTNC存在的情况下，将其暴露于冷水中后，可以保持干净，明亮的金属表面。纳米复合材料样品通过在金属表面上自发发生物理吸附作用，如ΔG°的负值所示 新鲜制备的样品为6％，陈年十二个月的样品为97.5％）。此外，扫描电子显微镜（SEM）的照片显示：在SNPs-CTNC存在的情况下，在一年的浸泡时间中，在有SNPs-CTNC存在的情况下，将其暴露于冷水中后，可以保持干净，明亮的金属表面。纳米复合材料样品通过在金属表面上自发发生物理吸附作用，如ΔG°的负值所示 新鲜制备的样品为6％，陈年十二个月的样品为97.5％）。此外，扫描电子显微镜（SEM）的照片显示：在SNPs-CTNC存在的情况下，在一年的浸泡时间中，在有SNPs-CTNC存在的情况下，将其暴露于冷水中后，可以保持干净，明亮的金属表面。纳米复合材料样品通过在金属表面上自发发生物理吸附作用，如ΔG°的负值所示_吸附（等于-18.002kJ·mol ^-1）。发现以表面覆盖率（θ）表示的吸附数据很好地线性拟合到Langmuir吸附等温线，具有正平衡且相对较大的结合平衡常数（K）（43.6）值，代表了被吸附的纳米复合颗粒之间的强吸引力和金属表面。这些纳米复合颗粒在金属表面上的吸附方式已根据带负电的胶体SNP与带正电的金属表面之间的静电相互作用进行了解释。