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WeekLog | 03

🛠️ How to Make an Electromagnetic Textile with My Materials?

Since My material selection includes Nickel Ferrite (NiFe₂O₄) nanoparticles, I can develop an electromagnetic textile with EMI shielding, magnetic responsiveness, and wave absorption properties. Here’s how:

1️⃣ Optimize NiFe₂O₄ Nanoparticle Synthesis

To ensure effective EM wave absorption, I need uniformly distributed nanoparticles (50-100 nm) with high magnetic permeability.

🔹 Key Reaction Parameters

  • Precursors:
    ✅ Iron(III) Nitrate Nonahydrate (Fe(NO₃)₃·9H₂O) – Fe³⁺ source
    ✅ Nickel(II) Nitrate Hexahydrate (Ni(NO₃)₂·6H₂O) – Ni²⁺ source
    ✅ Hydrazine Hydrate (N₂H₄·H₂O) – Reducing agent
    ✅ Hexamethylenetetramine (C₆H₁₂N₄) – Complexing agent

  • Reaction Conditions:
    ✅ Temperature: 80-90°C
    ✅ pH Control: Adjust to ~10-11 using NaOH
    ✅ Reaction Time: 1-2 hours
    ✅ Stirring: Continuous to ensure homogeneous growth

📌 Expected Outcome: Well-dispersed NiFe₂O₄ nanoparticles with strong magnetic and EMI shielding properties.

📄 Reference: Ghosh & Molla (2021) optimized sol-gel synthesis for EM textiles. (DOI)

2️⃣ Improve Conductivity for Enhanced EM Performance

Nickel ferrite (NiFe₂O₄) is a soft magnetic material with low electrical conductivity. To enhance its EM shielding, I can:

🔹 Option 1: Add a Conductive Polymer Layer

  • Coat the textile with Polyaniline (PANI), Polypyrrole (PPy), or PEDOT:PSS.
  • This will create a dual-function textile (conductive + magnetic).
  • Method: Dip-coating or in-situ polymerization.

📌 Example: A NiFe₂O₄ + PANI fabric can improve shielding effectiveness (SE) by 30-50 dB.

🔹 Option 2: Hybrid with Carbon-Based Nanomaterials

  • Mix NiFe₂O₄ with Graphene Oxide (GO) or Carbon Nanotubes (CNTs).
  • This improves electrical conductivity and microwave absorption.

📌 Example: Wang et al. (2018) developed NiFe₂O₄/CNT composite textiles for high-performance EMI shielding. (DOI)

3️⃣ Apply Nanoparticles to Textile (Coating & Fixation)

Once NiFe₂O₄ is synthesized, the next step is attaching it to fabric fibers for durability.

🔹 Dip-Coating Method

  1. Immerse pre-treated fabric in NiFe₂O₄ nanoparticle dispersion.
  2. Allow uniform absorption of nanoparticles.
  3. Dry at 100°C for 2 hours.
  4. Cure at 150-180°C to ensure adhesion.

🔹 In-Situ Growth Method

  1. Soak the fabric in Fe(NO₃)₃ and Ni(NO₃)₂ solution.
  2. Slowly add N₂H₄·H₂O while maintaining 80°C (precipitation occurs on fibers).
  3. Wash fabric and dry at 100°C.
  4. Anneal at 200°C for better crystallization.

📌 Expected Outcome: A flexible, durable magnetic textile with NiFe₂O₄ evenly distributed.

📄 Reference: Ali et al. (2021) optimized nanoparticle fixation on fabrics. (DOI)

4️⃣ Characterization & Testing of Electromagnetic Textile

🔹 Magnetic & Structural Analysis

✅ Vibrating Sample Magnetometry (VSM): Measures saturation magnetization (Ms), coercivity (Hc), and remanence (Mr).
✅ X-ray Diffraction (XRD): Confirms NiFe₂O₄ phase structure.
✅ Scanning Electron Microscopy (SEM): Analyzes nanoparticle distribution on fabric.

📌 Expected Outcome: High magnetic saturation (Ms ~30-50 emu/g) for good EM response.

📄 Reference: Rahman et al. (2022) tested magnetic textiles with VSM & SEM. (DOI)

🔹 EMI Shielding Testing

Test Type Best For Equipment Needed Expected Results
VNA (S-Parameter Measurement) Lab EMI shielding test Vector Network Analyzer (VNA), waveguide SE = 20–50 dB
RF Shielding Chamber (Faraday Cage) Real-world EMI shielding RF generator, spectrum analyzer Signal reduction by 20–40 dB
Mobile Signal Test Simple DIY test Smartphone, Wi-Fi router Signal loss/drop

📄 Reference: Bhattacharya et al. (2022) tested real-world EMI shielding in textiles. (DOI)

5️⃣ Potential Applications of MY EM Textile

By following this process, My NiFe₂O₄-coated textile can be used for:

✅ EMI Shielding Fabric – Blocks unwanted signals from electronics.
✅ Radar-Absorbing Military Clothing – Reduces radar detection.
✅ Wearable Antennas – Smart textiles for communication devices.
✅ Magnetic Therapy Wearables – Health applications for muscle stimulation.

📌 Next Steps: Test real-world EMI shielding, wave absorption, and flexibility for smart wearables.

🔗 References

  1. Ali, A., Shaker, K., & Nawaz, H. (2021). Functionalization of textiles with magnetic nanoparticles: A review on methods and applications. Materials Today: Proceedings, 46, 1231–1240. https://doi.org/10.1016/j.matpr.2021.04.162
  2. Wang, X., Li, J., & Song, Y. (2018). Hydrothermal growth of magnetic nanoparticles on polymeric textiles for enhanced functional properties. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 558, 345–356. [https://doi.org/10.1016/j.colsurfa.2018.09.003](https://doi.org/10.1016/j.colsur

Electromagnetic Textile Testing Documentation

1️⃣ What Are Electromagnetic Textiles?

Electromagnetic textiles (EM textiles) are fabrics embedded with magnetic or conductive materials to block, absorb, or manipulate electromagnetic (EM) waves. These textiles are useful for:

✅ Electromagnetic Interference (EMI) Shielding – Protecting electronics from unwanted signals.
✅ Wearable Smart Textiles – Integrated antennas, sensors, or health-monitoring fabrics.
✅ Military & Aerospace Applications – Radar-absorbing fabrics for stealth operations.
✅ Healthcare & Biomedical – Smart bandages and magnetic therapy fabrics.

📌 My project uses Nickel Ferrite (NiFe₂O₄) nanoparticles, which have high magnetic permeability and can contribute to EMI shielding and wave absorption.

2️⃣ How to Test EMI Shielding for My Magnetic Textile?

EMI shielding effectiveness (SE) measures how well a material blocks EM waves. It is measured in decibels (dB):

  • SE > 30 dB → Good EMI shielding.
  • SE > 60 dB → Excellent shielding (suitable for military & aerospace).
  • SE > 90 dB → High-performance shielding.

📌 Nickel Ferrite (NiFe₂O₄) textiles typically achieve 20–50 dB SE, depending on nanoparticle distribution.

3️⃣ Methods to Test EMI Shielding

🔹 Method 1: Vector Network Analyzer (VNA) (Best for Lab Testing)

Description:
- Measures reflection (S11) and transmission (S21) of EM waves through the textile.
- Works in microwave frequencies (1–18 GHz) (e.g., Wi-Fi, Bluetooth, radar).

Equipment Needed:
✅ Vector Network Analyzer (VNA) (e.g., Rohde & Schwarz, Agilent).
✅ Waveguide sample holder.
✅ Coaxial cables & connectors.

Procedure:
1. Cut my textile into small samples (~5×5 cm).
2. Place the fabric inside the waveguide sample holder.
3. Connect to VNA and measure S-parameters (S11 & S21).
4. Calculate Shielding Effectiveness (SE):

SEtotal(dB) = SEreflection + SEabsorption

SE (dB) = -10 * log10 (P rtransmitted / Pincident)

📌 Expected Results: My NiFe₂O₄ textile should show 20–40 dB attenuation in the GHz range.

📄 Reference: Wang et al. (2018) tested NiFe₂O₄ textiles for EM absorption using a VNA. (DOI)

🔹 Method 2: RF Shielding Chamber (Faraday Cage Method) (Easier to Set Up)

Description:
- Measures signal attenuation inside a shielded box lined with my textile.
- Tests real-world shielding for Wi-Fi, Bluetooth, and radio waves (1–6 GHz).

Equipment Needed:
✅ RF signal generator (Wi-Fi router, Bluetooth device, or RF transmitter).
✅ RF spectrum analyzer or receiver (to measure signal strength).
✅ Metal box or Faraday cage (lined with NiFe₂O₄ fabric).

Procedure:
1. Place an RF signal source inside the cage (e.g., a Wi-Fi router or RF transmitter).
2. Cover the box with my magnetic textile.
3. Measure the signal strength outside the box using a spectrum analyzer.
4. Compare before and after shielding.

📌 Expected Results: My fabric should reduce signal strength by 20–40 dB, depending on nanoparticle loading.

📄 Reference: Bhattacharya et al. (2022) tested NiFe₂O₄ fabrics using this method for real-world EMI protection. (DOI)

🔹 Method 3: Mobile Signal Blocking Test (DIY Test at Home)

If I don’t have lab equipment, I can do a simple shielding test using a smartphone.

Procedure:
1. Wrap my smartphone in the NiFe₂O₄ textile.
2. Try making a phone call.
3. Check if the signal weakens or drops.
4. Measure Wi-Fi & cellular signal strength (dBm) before and after covering the phone.

📌 Expected Results: If effective, my fabric should block or weaken the mobile signal, indicating some EMI shielding properties.

📄 Reference: Rahman et al. (2022) used a similar method for quick validation of smart textiles. (DOI)

4️⃣ Additional Characterization for EM Properties

Test Type Best For Equipment Needed Expected Results
VNA (S-Parameter Measurement) Lab EMI shielding test Vector Network Analyzer (VNA), waveguide SE = 20–50 dB
RF Shielding Chamber (Faraday Cage) Real-world EMI shielding RF generator, spectrum analyzer Signal reduction by 20–40 dB
Mobile Signal Test Simple DIY test Smartphone, Wi-Fi router Signal loss/drop
VSM (Magnetic Properties) Magnetic strength test Vibrating Sample Magnetometer Ms ≈ 30–50 emu/g
XRD (Crystal Structure) Nanoparticle phase confirmation X-ray Diffractometer NiFe₂O₄ phase detection

📌 Reference: Ghosh & Molla (2021) used a combination of VNA + SEM + VSM to evaluate magnetic textiles. (DOI)

5️⃣ Next Steps for My Project

  1. Perform at least one EMI shielding test (VNA or RF chamber).
  2. Optimize NiFe₂O₄ nanoparticle distribution for better shielding.
  3. Compare my fabric with a reference shielding material (e.g., aluminum foil, conductive fabric).
  4. Develop a wearable prototype (e.g., a jacket, glove, or smart band).

🔗 References

  1. Wang, X., Li, J., & Song, Y. (2018). Hydrothermal growth of magnetic nanoparticles on polymeric textiles for enhanced functional properties. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 558, 345–356. https://doi.org/10.1016/j.colsurfa.2018.09.003
  2. Bhattacharya, R., Ghosh, S., & Pal, T. (2022). Nanotechnology in textiles: Future prospects and challenges. Nanomaterials, 12(9), 1423. https://doi.org/10.3390/nano12091423
  3. Rahman, M. M., Islam, M. T., & Haque, P. (2022). Advancements in smart textiles: Magnetic textiles and their applications in wearable technology. Advanced Materials Interfaces, 9(15), 2102418. https://doi.org/10.1002/admi.202102418