Amphiphilic · pH-Responsive Diblock Copolymer
PEG-b-P4VP
Also written 4VP-PEG copolymer, mPEG-b-P4VP | Block architecture — not a random copolymer
A diblock copolymer of poly(ethylene glycol) (PEG) covalently joined end-to-end to poly(4-vinylpyridine) (P4VP) — two chemically distinct chains fused at a single junction point, not randomly mixed along one backbone. The PEG block is permanently hydrophilic; the P4VP block flips between hydrophobic (neutral, high pH) and hydrophilic (protonated, low pH). That contrast is what drives the pair to self-assemble into pH-switchable micelles, vesicles, and nanostructured thin films.
- Custom PEG:P4VP block ratio, multiple Mw grades
Custom composition
H₃CO-(C₂H₄O)ₓ-b-(C₇H₇N)ₘ
PEG-b-P4VP
Appearance: White to off-white powder
Character: Amphiphilic, pH-switchable
Architecture: Linear diblock (A-b-B)
Storage: 2–8 °C, sealed, dry
ISO 9001:2015
Manufactured under certified quality management
Custom Block Ratio
PEG:P4VP block length set independently, to order
Batch-Level COA
Mn, Đ, and block-length confirmation per lot
Sample to Bulk
Gram-scale R&D up to bulk supply
CAS No.
Composition-dependent
Molecular Formula
H₃CO-(C₂H₄O)ₓ-b-(C₇H₇N)ₘ
Character
Amphiphilic, pH-switchable
Mn Range
5K – 100K
Form
Powder
Why "block" matters here
Unlike a random copolymer, a diblock's two segments stay chemically segregated — which is exactly what lets them self-assemble instead of just blending into one uniform chain.
PEG block: always hydrophilic
Non-ionic and water-loving at every pH, the PEG segment forms the corona (shell) of any self-assembled structure and gives it stealth, water solubility.
P4VP block: pH-switchable
Neutral and hydrophobic above its apparent pKa (~4–5), protonated and hydrophilic below it — this is the block that turns self-assembly on and off.
Block ratio sets morphology
The relative length of each block (the PEG volume fraction) determines whether the copolymer favors spherical micelles, worms, or vesicles.
Quaternizable, metal-coordinating core
Once assembled, the P4VP core's pyridine N can still be alkylated or used to template and stabilize metal nanoparticles inside the micelle.
This follows the general packing-parameter trend seen across amphiphilic block copolymers: as the hydrophilic (PEG) fraction shrinks relative to the hydrophobic (neutral P4VP) fraction, curvature drops and morphology shifts from spheres toward worms and bilayer vesicles. At low pH, protonated P4VP behaves more hydrophilic, which can shift or collapse this self-assembly entirely.
Values below are representative for this block pair. Batch-specific COAs with GPC and block-length data are available on request.
Chemical Name | Poly(ethylene glycol)-block-poly(4-vinylpyridine) |
|---|---|
| Synonyms | PEG-b-P4VP · mPEG-b-P4VP · 4VP-PEG copolymer · Poly(ethylene glycol)-block-poly(4-vinylpyridine) |
| Blocks | Poly(ethylene glycol) (PEG, methoxy-capped) · Poly(4-vinylpyridine) (P4VP) |
| Architecture | Linear A-b-B diblock — segregated, not statistically distributed |
| PEG : P4VP Block Ratio | Custom / composition-dependent — commonly 10:90 to 90:10 by weight |
| CAS Number | Not applicable — composition-specific block copolymers are not assigned a single CAS RN |
| Molecular Weight (Mn) | Custom synthesis, typically 5,000–100,000 g/mol total (each block independently specified) |
| Dispersity (Đ) | 1.05–1.20 (living/controlled polymerization from a PEG macroinitiator) |
| Appearance | White to off-white powder |
| Solubility | Water and common organics (THF, DMF); self-assembles into micelles above a critical concentration in selective solvents |
| Key Functional Groups | PEG ether (hydrophilic, stealth) · pyridine (basic, quaternizable, metal-coordinating) |
| Storage | Sealed, dry, 2–8 °C, protected from light |
Need a specific PEG:P4VP block ratio or a pre-formed micelle formulation? Talk to technical sales →
Choose the ratio that fits your target morphology
PEG:P4VP block ratio is the main lever for self-assembled morphology in a selective (water-based) solvent.
PEG : P4VP ≈ 70:30
PEG-dominant
High curvature favors small spherical micelles with a dense PEG corona — a common starting point for drug-delivery carriers.
PEG : P4VP ≈ 50:50
Balanced
Intermediate curvature can yield wormlike micelles or mixed morphologies, useful for exploring assembly behavior.
PEG : P4VP ≈ 30:70
P4VP-dominant
Low curvature favors vesicles/polymersomes and thicker P4VP domains — suited to nanolithography templates and encapsulation.
Applications
pH-responsive micellar drug delivery
A hydrophobic P4VP core loads poorly water-soluble drugs; protonation at low (e.g. endosomal or tumor) pH swells and disassembles the micelle to release cargo.
Block copolymer lithography
Thin-film microphase separation creates regular nanoscale PEG/P4VP domains used as etch templates for nanopatterning and porous membranes.
Metal nanoparticle synthesis
The pyridine-rich P4VP domain coordinates and helps reduce/stabilize metal salts (Au, Ag, Pt), templating nanoparticle size and spacing.
Polymersomes & vesicles
Lower PEG fractions favor bilayer vesicle formation, useful for encapsulating hydrophilic cargo behind a P4VP-rich, pH-responsive membrane.
Nanoporous membrane templating
Selective swelling or removal of the P4VP domain from a self-assembled film leaves a nanoporous PEG-rich membrane structure.
Stimuli-responsive thin films
Surface-tethered PEG-b-P4VP films swell and reorganize with pH, enabling switchable wettability or permeability coatings.
Compatibilizer / interfacial modifier
Bridges hydrophilic and pyridine-compatible domains in polymer blends, coatings, or hybrid organic-inorganic interfaces.
Directed self-assembly (DSA)
Used in nanolithography research as a model amphiphilic system for guided pattern formation on pre-patterned substrates.
Data & safety documents
Batch-specific COAs with GPC, ¹H-NMR block-length confirmation, and DLS micelle-sizing data available for order confirmations. Contact us for a specific lot number.
Safety Data Sheet
GHS-format · EN / ZH
Certificate of Analysis
Ratio + Mw confirmation
DLS Micelle Sizing
Hydrodynamic diameter vs. pH
FAQ
Most frequent questions and answers
It’s used wherever a pH-switchable, self-assembling amphiphile is needed — pH-responsive micellar drug delivery, block copolymer lithography templates, metal nanoparticle synthesis, polymersomes, and stimuli-responsive thin films — because the PEG block and P4VP block phase-separate into a corona and core (or matrix and domain) instead of blending together.
Block. “4VP-PEG copolymer” almost always refers to this PEG-b-P4VP diblock architecture — a PEG chain and a P4VP chain joined end-to-end at one junction — which is chemically and functionally different from Poly(4VP-co-PEGMA), a random comb copolymer where short PEG side chains are scattered along a single backbone. If you actually need the random comb version, let us know and we’ll point you to that product instead.
In water above its critical micelle concentration, the hydrophilic PEG block extends outward to form a soluble corona while the more hydrophobic (neutral) P4VP block collapses inward to form the micelle core — the same driving force behind essentially all amphiphilic block copolymer self-assembly.
Yes — this is the defining feature of this pair. Below the pyridine’s apparent pKa (~4–5), the P4VP core protonates, becomes hydrophilic, and swells or disassembles the micelle; above it, the core stays collapsed and hydrophobic, favoring stable micelles. This is the basis for pH-triggered loading and release in drug-delivery applications.
Both block lengths are specified independently at synthesis. As a general trend, higher PEG fractions favor small spherical micelles, intermediate fractions can give wormlike micelles, and lower PEG fractions favor bilayer vesicles (polymersomes) — the same packing-parameter trend seen across amphiphilic block copolymers generally.
Yes. The pyridine nitrogen in the P4VP domain coordinates metal ions (e.g. Au³⁺, Ag⁺, Pt²⁺/⁴⁺), and the confined P4VP micelle core or thin-film domain can template nanoparticle nucleation, size, and spacing — a well-established route in nanoparticle synthesis literature.
Yes. Thin films of PEG-b-P4VP microphase-separate into regular nanoscale domains that can serve as etch masks or templates for nanopatterning, and the P4VP domain’s swelling behavior is also used to create nanoporous membranes after selective processing.
No — composition-specific block copolymers like this one are not assigned a single CAS Registry Number, since each block’s molecular weight and the overall dispersity are set per synthesis batch. Each lot’s COA documents the actual block lengths and total Mn.