Analytical-Grade Colloidal Polystyrene Nanospheres
 

  • CV< 3%;

  • Roundness > 0.980;

  • Non-cross-linked; 

  • Surface Chemistry: Non-functionalized or carboxyl-terminated (-COOH): for sizes 100 - 1000 nm;

  • Provided in Milli-Q water with a trace amount of surfactant (<0.1%);

  • Concentrations available: 10 - 100 mg/ml (i.e. 1 - 10% w/v);

  • Sizes available: 100 - 1000 nm;

  • Lifetime: At least 1 year from the date of product delivery;

  • Can be easily surface-functionalized via chemical bond formation;

  • Can be adapted to other common biological buffers like phosphate-buffered saline (PBS) or organic solvents like ethanol via repeated centrifugation and resuspension;

  • Might precipitate at the bottom of the containing vial over time, and this is not a sign of aggregation. Large particles precipitate faster than small particles. These particles can be easily resuspended using sonication (ultrasonic bath or ultrasonic homogenizer) or vortexing;

  • Only priced based on the solid content; for instance, 50 ml of the polystyrene nanospheres at 10mg/ml would have the same price as 10 ml of the polystyrene nanospheres at 50 mg/ml.

  • For instance, 100 nm polystyrene nanoparticles can be used for interfacial studies and other biomedical applications while 1 μm colloidal polystyrene nanoparticles can be used for size standards.

Safety Data Sheets

Transmission/Scanning Electron Micrographs​

100 nm

Carboxylated

100 nm

Non-
Functionalized

200 nm

Carboxylated

200 nm

Non-
Functionalized

300 nm

Carboxylated

400 nm

Carboxylated

400 nm

Non-
Functionalized

500 nm

Carboxylated

500 nm

Non-
Functionalized

600 nm

Non-
Functionalized

800 nm

Non-
Functionalized

1000 nm

Carboxylated

1000 nm

Non-
Functionalized

The preparation process for this product is mature and stable. Each batch of products is verified by various precision instruments such as high-resolution transmission electron microscopy, field emission scanning electron microscopy, particle size analyzer, and ultraviolet-visible spectroscopy. The series of monodisperse microspheres have high sphericity, strictly monodisperse particle size, small coefficient of variation and stable physical and chemical properties. Our polystyrene nanoparticles have nearly perfect sphericity and a narrow particle size distribution. These nanospheres have extremely stable physicochemical properties, are easy to store, and have good stability. The surface of the carboxylated spheres is rich in carboxylic functional groups and is easy to functionalize. The applications of these monodisperse polystyrene nanoparticles include the synthesis of the ordered materials, biomedical tests, particle size standards, and column packing.

Analytical-Grade Colloidal Polystyrene Microspheres
 

  • CV< 5% for 2 μm ~ 50 μm; CV < 20% for 100 μm;

  • Roundness > 0.980;

  • Surface Chemistry:
    Non-functionalized or carboxyl polystyrene microparticles: for sizes 5- 20 
    μm;
    Non-functionalized polystyrene microparticles: for sizes 20 - 100 
    μm;

  • Provided in Milli-Q water with a trace amount of surfactant (<0.1%);

  • Concentration available to choose from: 10 - 50 mg/ml (i.e. 1 - 5 % w/v);

  • Can be easily surface-functionalized via chemical bond formation;

  • Can be adapted to other common biological buffers like phosphate-buffered saline (PBS) or organic solvents like ethanol via repeated centrifugation and resuspension;

  • These polystyrene microparticles might precipitate at the bottom of the containing vial over time, and this is not a sign of aggregation. Large particles precipitate faster than small particles. These particles can be easily resuspended using sonication (ultrasonic bath or ultrasonic homogenizer) or vortexing;

  • Our polystyrene microparticles are only priced based on the solid content; for instance, 50 ml of the polystyrene nanospheres at 10 mg/ml would have the same price as 10 ml of the polystyrene nanospheres at 50 mg/ml.

  • Polystyrene microparticles can be used for many applications similar to those involving PMMA microparticles but polystyrene microparticles are lower in density than PMMA microparticles. 

Scanning Electron Micrographs ​

2 μm
Non-
Functionalized

2 μm
Carboxylated

5 μm
Non-
Functionalized

5 μm
Carboxylated

10 μm
Carboxylated

10 μm
Non-
Functionalized

20 μm
Carboxylated

20 μm
Non-
Functionalized

50 μm
Non-
Functionalized

Zeta Potential Measurement Results

Fourier-transform infrared spectroscopy (FTIR) Results of 1 μm Polystyrene Microspheres 

How do we measure the CV Values and reveal the real size distributions?

Through the years of working with nano-/microspheres, our researchers and technicians fully understand the importance of the size distributions from batch to batch. In the field of size characterizations, there are mainly two methods, scanning/transmission/scanning transmission electron micrographs (SEM/TEM/STEM) and dynamic light scattering (i.e. DLS). Unfortunately, we found DLS are unsuitable for accurately determine the size distributions of nano-/microspheres when compared to SEM/TEM/STEM techniques. 
 

  • DLS results are closely related to colloidal stability, and as an inevitable result, the size distributions will not be accurate for large-sized nanoparticles. For nanoparticles below 100 nm, the hydrodynamic sizes become relevant. However, for nanoparticles around or above a few hundred nanometers, colloidal stability is greatly affected by the role of gravity. In comparison, the SEM/TEM/STEM images are based on dry samples only where higher reproducibility and reliability have been seen through numerous studies in our case and in the literature.

  • DLS cannot distinguish between nanoparticles themselves and the aggregates of surfactants. As most of our colloidal nano-/microspheres have a trace of surfactants purposely added in the system for longer lifetime, DLS becomes unsuitable for direct size measurements unless the nano-/microspheres are washed at least three times with the Milli-Q water or de-ionized water to fully remove any trace of surfactants. Similarly, the nano-/microspheres due to inefficient re-suspension also distort the DLS results; for instance, a couple of aggregated 100 nm nanoparticles might be seen as 200 nm or 300 nm nanoparticles under DLS measurements.

  • DLS cannot give any insight into the shape or the spherical degree of nano-/microspheres. Irregularly-shaped particles and perfectly spherical particles can be interpreted the same under DLS measurements.

 

As a result, we use SEM/TEM/STEM techniques instead of DLS measurements as our routine quality control method. We routinely take at least 10 electron micrographs and process them with ImageJ for size distributions as well as the CV value. This is also the reason that we typically include a couple of representative SEM/TEM/STEM images with our products when delivered to our clients. We wish to reveal the real size distributions and let the clients visualize the images of nano-/microspheres directly instead of viewing the fitted curves indirectly. 

Daily Exchange Rates
(updated every 12 hr)

For Carboxylated Ones:

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For Non-Functionalized Ones:

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Please note:
 

1. We accept both online purchases at our online store or Amazon stores and invoiced orders (Net 30 Terms). In-stock items will be dispatched within 1-3 business days and the lead time for customized orders will be evaluated on a case-by-case basis.

2. Orders destined for the US will be shipped from one of our two US offices. Orders destined for the UK and the EU will be shipped from the UK office. Orders destined for Canada will be shipped from our Canadian headquarters. No duties or any additional taxes for the orders delivered to Canadian, the US and the UK addresses, regardless of the selected sales channel. For other International shipping addresses, recipients are responsible for local duties and taxes.

3. Free exchanges or full refunds will be offered within 30 days after the order fulfilment without any questions asked if the ordered items fail to meet customer expectations.

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