Table 1.
PDMS surface modification strategies to alleviate problems related to nonspecific adsorption and/or absorption.
| Modification method | Derivatization of PDMS substrate | Stability | Water contact angle (WCA) (θ/°) | Ref. |
|---|---|---|---|---|
| O2 plasma | n/a | 6 hours | between 50–60 | [36] |
| UV/ozone treatment | n/a | 4.5 months | 46 | [91] |
| Corona discharge | n/a | 1 hours | 50 | [92] |
| Sol-gel method | PDMS modified with TiO2 and derivatized with oligoethyleneoxide | 1 months | 23 | [94] |
| LBL deposition | PDMS coated with PEMs by carbodiimide coupling and covalent attachment of PEG chains | 5 months | 20 | [97] |
| LBL deposition | PDMS covered with PEMs and functionalized with protein G | 4 weeks | between 7.81–21.61 | [100] |
| Non-ionic surfactant | Pluronic added into uncured PDMS | 2 weeks | 62.8 | [104] |
| Non-ionic surfactant | PDMS coated with copoly(DMA-GMA) film | 6 months | 7 | [105] |
| Charged polymers | Immersed into aqueous solution containing PLL-g-PEG copolymers | n/a | 35 | [109] |
| Charged polymers | Coated with PEG | n/a | 58 (advancing) 17 (receding) | [110] |
| Surface segregation and SAMs | ATRP initiator was mixed with PDMS prepolymer and cured in contact with alkylthiolate monolayer | n/a | 58 | [35] |
| Surface segregation and SAMs | PDMS pre-polymer was mixed with a functional molecule, alkenes self-assembled near the functionalized monolayer and reacted with the PDMS backbone | n/a | 83 (static) 33 (advancing) 19 (receding) | [113] |
| Surface segregation and SAMs | Cross-linked PEG silane layers were created on the PDMS surfaces | > 2 months | 33 (advancing) 19 (receding) | [114] |
| Surface segregation and SAMs | Adding PEG molecules into PDMS prepolymer before curing | n/a | 75 | [115] |
| Silanization | PDMS surface silanized with APTES ± GA | n/a | < 60 | [38] |
| Silanization | PDMS microchannels treated with GPTMS and exposed to NH2-PEG solutions | 1 month | 70 | [116] |
| Silanization | PDMS microchannels treated with CPTMS and exposed to alkyne-PEG solutions | 1 month | 64 | [117] |
| Grafting-to | Attachment of PEG onto air plasma treated PDMS surface | 47 days | 22 | [119] |
| Grafting-to | Channel coating of preceramic polymer, AHPCS, and subsequent hydrolysis | n/a | 35 | [120] |
| Grafting-from | MPC was grafted by surface-initiated photo-induced radical polymerization | n/a | 25 | [122] |
| Grafting-from | Grafting PNIPAAm film onto PDMS Surface | n/a | 30 67 (advancing) | [123] |
| Grafting-from | Silanization by MPTMS and PEG was conjugated with peroxide- initiated polymerization | 1 month | 58–65 | [124] |
| Grafting-from | After oxidation of the PDMS surface with UV-ozone plasma generator, ATRP with acrylamide was carried out. | 1 month | between 60–70 (advancing) 5 (receeding) | [127] |
| Grafting-from | PVP chains were grafted from the PDMS surface by SI-ATRP | n/a | 32 (advancing) | [128] |
| Grafting-from | A quaternized polyDMAEMA was grafted onto PDMS surface via copper-mediated ATRP. | n/a | 49.9 (advancing) | [129] |
Abbreviations: TiO2, Titanium dioxide; PEMs, polyelectrolate multilayer; PEG, poly(ethylene glycol); DMA, dimethylmethacrylate; GMA, glycidyl methacrylate; PLL, poly(L-lysine); PEG, poly(ethylene glycol); APTES, (3-aminopropyl) triethoxy silane; GA, glutaraldehyde; GPTMS, 3-glycidoxypropyltrimethoxysilane; CPTMS, 3-chloropropyltrichlorosilane; AHPCS, allylhydridopolycarbosilane; MPC, 2-methacryloyloxyethyl phosphorylcholine; PNIPAAm, poly(N-isopropylacrylamide); MPTMS, 3-methacryloxypropyltrimethoxysilane; MPC, 2-methacryloyloxyethyl phosphorylcholine; PVP, poly(N-vinylpyrrolidone); DMAEMA, dimethylaminoethyl methacrylate.